Document:

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                                                                    EXHIBIT 4-AE

                         ---------------------------------
                          FIFTH SUPPLEMENTAL INDENTURE

                                     between

                             HERCULES INCORPORATED,
                                    as Issuer

                                       and

                            THE CHASE MANHATTAN BANK,
                                   as Trustee

                          Dated as of January 24, 2000

                         ---------------------------------
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                                TABLE OF CONTENTS

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                                                  ARTICLE 1

         SECTION 1.01.  Definitions...................................................................            2

                                                  ARTICLE 2

         SECTION 2.01.  Ratification of Base Indenture, the First Supplemental Indenture,
                                   the Second Supplemental Indenture and the Third
                                    Supplemental Indenture:
                                    Fifth Supplemental Indenture Controls.............................            2
         SECTION 2.02.  Trustee Not Responsible for Recitals..........................................            2
         SECTION 2.03.  Governing Law.................................................................            2
         SECTION 2.04.  Severability..................................................................            2
         SECTION 2.05.  Counterparts..................................................................            2
         SECTION 2.06.  Terms Defined.................................................................            2
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         FIFTH SUPPLEMENTAL INDENTURE, dated as of January 24, 2000 (the "FIFTH
SUPPLEMENTAL INDENTURE"), between Hercules Incorporated, a Delaware corporation
(the "Company"), and The Chase Manhattan Bank, a New York banking corporation,
as trustee (the "TRUSTEE").

         WHEREAS, the Company and the Trustee are parties to the Junior
Subordinated Debentures Indenture dated as of November 12, 1998 between the
Company and the Trustee (the "BASE INDENTURE"), as supplemented by a First
Supplemental Indenture dated as of November 12, 1998 between the Company and the
Trustee (the "FIRST SUPPLEMENTAL INDENTURE"), a Second Supplemental Indenture
dated as of July 6, 1999 (the "SECOND SUPPLEMENTAL INDENTURE") and a Third
Supplemental Indenture dated as of October 25, 1999 (the "THIRD SUPPLEMENTAL
INDENTURE" and together with the Base Indenture, the First Supplemental
Indenture, the Second Supplemental Indenture and this Fifth Supplemental
Indenture, the "INDENTURE");

         WHEREAS, the Company executed and delivered the Base Indenture to the
Trustee to provide for the issuance of the Company's unsecured junior
subordinated debentures (the "DEBENTURES") to be issued from time to time in one
or more series as might be determined by the Company under the Indenture, in an
unlimited aggregate principal amount which may be authenticated and delivered as
provided in the Base Indenture;

         WHEREAS, pursuant to the terms of the Indenture in the First
Supplemental Indenture, the Company provided for the establishment of a new
series of its Debentures known as its Auction Rate Reset Junior Subordinated
Notes Series A (the "SUBORDINATED NOTES");

         WHEREAS, the Indenture provides that the Company and the Trustee may
amend the Indenture, with the consent of at least a majority in the aggregate
principal amount of the Debentures affected thereby, to provide for, among other
things, a change in the stated maturity of that series of Debentures;

         WHEREAS, the Company and the Trustee desire to modify certain
provisions of the Indenture to extend the maturity date of the Subordinated
Notes;

         WHEREAS, all things necessary to make this Fifth Supplemental Indenture
a valid indenture and agreement according to its terms have been done;

         NOW THEREFORE, in consideration of the purchase and acceptance of the
Subordinated Notes by the Holder thereof, and for the purpose of amending and
restating certain terms of the Indenture relating to the stated maturity of the
Subordinated Notes, the Company covenants and agrees with the Trustee as
follows:
<PAGE>   4
                                    ARTICLE 1

         SECTION 1.01. Definitions. The definition of "Maturity Date" contained
in Section 1.01 of the Second Supplemental Indenture is hereby amended to read
in its entirety as follows:

         ""MATURITY DATE" means February 28, 2000."

                                    ARTICLE 2

         SECTION 2.01. Ratification of Base Indenture, the First Supplemental
Indenture, the Second Supplemental Indenture and the Third Supplemental
Indenture: Fifth Supplemental Indenture Controls. The Base Indenture, as
supplemented by the First Supplemental Indenture, the Second Supplemental
Indenture, the Third Supplemental Indenture and this Fifth Supplemental
Indenture, is in all respects ratified and confirmed, and this Fifth
Supplemental Indenture shall be deemed part of the Base Indenture in the manner
and to the extent herein and therein provided. The provisions of this Fifth
Supplemental Indenture shall supersede the provisions of the Base Indenture, the
First Supplemental Indenture, the Second Supplemental Indenture and the Third
Supplemental Indenture to the extent the Base Indenture, the First Supplemental
Indenture, the Second Supplemental Indenture or the Third Supplemental Indenture
is inconsistent herewith.

         SECTION 2.02. Trustee Not Responsible for Recitals. The recitals herein
contained are made by the Company and not by the Trustee, and the Trustee
assumes no responsibility for the correctness thereof. The Trustee makes no
representation as to the validity or sufficiency of this Fifth Supplemental
Indenture.

         SECTION 2.03. Governing Law. This Fifth Supplemental Indenture shall be
governed by and construed in accordance with the laws of the State of New York,
as applied to contracts made and performed within the State of New York, without
regard to its principles of conflicts of laws.

         SECTION 2.04. Severability. If any provision in the Base Indenture, the
First Supplemental Indenture, the Second Supplemental Indenture, the Third
Supplemental Indenture, this Fifth Supplemental Indenture or in the Subordinated
Notes shall be invalid, illegal or unenforceable, the validity, legality and
enforceability of the remaining provisions shall not in any way be affected or
impaired thereby.

         SECTION 2.05. Counterparts. The parties may sign any number of copies
of this Fifth Supplemental Indenture. Each signed copy shall be an original, but
all of them together represent the same agreement. Any signed copy shall be
sufficient proof of this Fifth Supplemental Indenture.

         SECTION 2.06. Terms Defined. All terms defined elsewhere in the
Indenture shall have the same meanings when used herein.

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         IN WITNESS WHEREOF, the parties hereto have caused this Fifth
Supplemental Indenture to be duly executed as of the day and year first above
written.

                                        HERCULES INCORPORATED,
                                              as Issuer

                                        By:
                                           -----------------------------------
                                                 Name:
                                                 Title:

                                        THE CHASE MANHATTAN BANK,
                                                 as Trustee

                                        By:
                                           -----------------------------------
                                                 Name:
                                                 Title:<PAGE>   1
                                                                    EXHIBIT 4-AF

                             AMENDMENT NO. 4 TO THE
                      AMENDED AND RESTATED TRUST AGREEMENT

         This AMENDMENT NO. 4 (the "AMENDMENT") is made as of February 9, 2000,
by Israel J. Floyd, Stuart C. Shears and Michael J. Scott (collectively, the
"ADMINISTRATIVE TRUSTEES"), The Chase Manhattan Bank, as Property Trustee
("CHASE"), Hercules Incorporated, a Delaware corporation (the "SPONSOR"), and by
the Holders, from time to time, of undivided beneficial interests in the assets
of Hercules Trust V (the "TRUST"), a business trust created pursuant to a Trust
Agreement dated as of October 14, 1998, as amended by the Amended and Restated
Trust Agreement dated as of November 12, 1998, the Amendment to the Amended and
Restated Trust Agreement dated as of July 6, 1999, the Amendment No. 2 to the
Amended and Restated Trust Agreement dated as of October 25, 1999 and the
Amendment No. 3 to the Amended and Restated Trust Agreement dated as of January
24, 2000 (as amended, the "TRUST AGREEMENT").

         WHEREAS, the Trustees and the Sponsor have established the Trust
pursuant to the Trust Agreement for the sole purpose of issuing and selling
certain securities representing undivided beneficial interests in the assets of
the Trust (the "SECURITIES") having such terms as are set forth in Annex I
thereto ("ANNEX I") and investing the proceeds thereof in the Auction Rate Reset
Junior Subordinated Notes Series A of the Sponsor (the "SUBORDINATED NOTES") and
engaging in only those activities necessary, advisable or incidental thereto;

         WHEREAS, the Trust Agreement and Annex I provide for amendment of the
Trust Agreement and the Securities, subject to satisfaction of certain
requirements;

         WHEREAS, the parties hereto desire to extend the Mandatory Redemption
Date (as defined in the Trust Agreement) and change the Distribution Rate (as
defined in Annex I) of the Securities and to provide for remarketing of the
Securities in certain circumstances;

         WHEREAS, this Amendment does not affect the rights, powers, duties,
obligations or immunities of the Property Trustee or of the Delaware Trustee;

         WHEREAS, all things necessary to make this Amendment a valid amendment
and agreement according to its terms have been done;

         NOW THEREFORE, in consideration of their mutual covenants contained
herein and in the Trust Agreement, the parties hereto, intending to be legally
bound, hereby mutually covenant and agree as follows:
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                                    ARTICLE 1

         SECTION 1.01. Amended Definitions. The following definitions contained
in Section 1.01 of the Trust Agreement are hereby amended to read in their
entirety as follows:

                  ""FAILED REMARKETING" has the meaning set forth in the
         Remarketing Agreement."

                  ""FINAL RESET DATE" has the meaning set forth in Section
         6.02(a)(ii)."

                  ""MANDATORY REDEMPTION DATE" means February 9, 2002; provided,
         that on and after the settlement of the sale of the Preferred
         Securities in a successful Remarketing, the Mandatory Redemption Date
         shall be the Remarketed Redemption Date; and provided, further, that,
         in accordance with Section 6.02(a)(iv), in the event the Sponsor elects
         to pay the aggregate Liquidation Amount of and accumulated and unpaid
         Distributions on the Preferred Securities upon receipt of the
         Remarketing Notice, and notifies the Remarketing Agent of such election
         within five Business Days thereafter, the Mandatory Redemption Date
         shall be the date eight Business Days after receipt of the Remarketing
         Notice."

                  ""REMARKETING AGENT" means Banc of America Securities LLC."

                  ""REMARKETING AGREEMENT" means the Remarketing and Contingent
         Purchase Agreement dated as of February 9, 2000 among the Subordinated
         Note Issuer, the Trust and the Remarketing Agent."

                  ""REMARKETING PRICE" means 100% of the aggregate stated
         Liquidation Amount of the Preferred Securities."

                  ""SECONDARY PURCHASE AGREEMENT" means an agreement to be dated
         as of the Reset Date (or such other date as permitted by applicable
         law) among the Sponsor, the Trust, the Remarketing Agent and the
         Secondary Purchaser, in the form agreed among the Sponsor, the Trust,
         the Remarketing Agent and the Secondary Purchaser."

         SECTION 1.02. Additional Definitions. The following definitions are
hereby inserted in the appropriate alphabetical order in Section 1.01 of the
Trust Agreement:

                  ""AFFILIATED BIDDER" has the meaning set forth in Section
         6.02(b)."

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                  ""FINAL RESET DATE" has the meaning set forth in Section
         6.02(a)(ii)."

                  ""PRE-REMARKETING DISTRIBUTION DATE" has the meaning set forth
         in Section 2(b) of Annex I hereto."

                  ""REMARKETED REDEMPTION DATE" means the later of (i) the first
         anniversary of the Remarketing Settlement Date on which Replacement
         Securities are issued, and (ii) February 9, 2002."

                  ""REMARKETING NOTICE" has the meaning set forth in Section
         6.02(a)(i)."

                  ""REQUESTING HOLDERS" has the meaning set forth in Section
         6.02(a)(i)."

         SECTION 1.03. Deleted Definitions. The definitions of "Maturity
Extension Date" and "Remarketed Maturity Date" are hereby deleted in their
entirety from Section 1.01 of the Trust Agreement.

                                    ARTICLE 2

         SECTION 2.01. Application of Articles 1, 2 and 3. The provisions of
Article 1, Article 2 and Article 3 hereof shall apply to the Securities and the
certificates therefor shall be appropriately amended.

         SECTION 2.02. Amendment of Distribution Rate. Section 2 of Annex I is
hereby amended to read in its entirety as follows:

         "2. Distributions.

                  (a) "DISTRIBUTIONS" with respect to the Liquidation Amount of
         $1,000 per Security (the "LIQUIDATION AMOUNT") of each Security will
         accrue and be payable at a rate (the "DISTRIBUTION RATE") (such rate
         being the rate of interest payable on the Subordinated Notes to be held
         by the Property Trustee) per annum equal to

                           (i) from and including November 12, 1998 to but
                  excluding February 9, 2000, LIBOR plus 175 basis points;

                           (ii) from and including February 9, 2000 to but
                  excluding the earlier of (A) the Remarketing Settlement Date
                  on which

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                  Replacement Securities are issued and (B) the date such
                  Security is redeemed, LIBOR plus 150 basis points;

                           (iii) from and including the Remarketing Settlement
                  Date on which Replacement Securities are issued to but
                  excluding the date such Security is redeemed, the Winning Bid
                  Rate; and

                           (iv) notwithstanding clauses (i), (ii) and (iii)
                  above, if such Security is not redeemed because the
                  Subordinated Note Issuer fails to pay the principal amount of
                  the Subordinated Notes on the date such amount becomes due,
                  then from and including such due date to but excluding the
                  date such Security is redeemed, the applicable Distribution
                  Rate in effect on the due date, compounded quarterly, but only
                  to the extent permitted by applicable law.

         Distributions that are not paid when due will bear additional
         distributions ("ADDITIONAL DISTRIBUTIONS") thereon compounded quarterly
         at the applicable Distribution Rate in effect on the due date specified
         above (to the extent permitted by applicable law). A Distribution is
         payable only to the extent that payments are made in respect of the
         Subordinated Notes held by the Property Trustee and to the extent the
         Property Trustee has funds on hand legally available therefor.

                   (b) Until the Remarketing Settlement Date on which
         Replacement Securities are issued, Distributions on the Securities will
         be payable quarterly in arrears (i) on February 12, May 12, August 12
         and November 12 of each year, commencing February 12, 1999 and (ii) on
         such Remarketing Settlement Date (each, a "PRE-REMARKETING DISTRIBUTION
         DATE"), and will accumulate from and including the most recent date to
         which Distributions have been paid or, if no Distributions have been
         paid, from November 12, 1998, to but excluding the related
         Pre-Remarketing Distribution Date, except as otherwise described below.

         The Distribution Rate in effect for the period from and including
         November 12, 1998 to but excluding February 12, 1999 shall be the rate
         determined by the Calculation Agent two London Banking Days prior to
         November 12, 1998 and shall equal LIBOR plus 175 basis points. The
         Distribution Rate in effect from and including February 12, 1999 to but
         excluding February 9, 2000, for each quarterly period from and
         including the immediately preceding Pre-Remarketing Distribution Date
         to but excluding the applicable Pre-Remarketing Distribution Date,
         shall be determined by the Calculation Agent two London Banking Days
         prior to such immediately preceding Pre-Remarketing Distribution Date
         (a "DATE

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         OF DETERMINATION") and shall equal LIBOR plus 175 basis points. The
         Distribution Rate in effect thereafter, for each quarterly period from
         and including the immediately preceding Pre-Remarketing Distribution
         Date to but excluding the applicable Pre-Remarketing Distribution Date,
         shall be determined by the Calculation Agent two London Banking Days
         prior to such immediately preceding Pre-Remarketing Distribution Date
         and shall equal LIBOR plus 150 basis points. The amount of the
         Distribution payable on February 12, 2000 shall reflect the pro rata
         application of the two Distribution Rates applicable to the calculation
         period for such Distribution for each day on which the applicable
         Distribution Rate was in effect. The amount of Distributions payable
         for any quarterly period shall be computed on the basis of a 360-day
         year of twelve 30-day months. Except as provided in the last sentence
         of this paragraph, the amount of Distributions payable for any period
         shorter than a full quarterly period for which Distributions are
         computed will be computed on the basis of the actual number of days
         elapsed per 30-day month. If a Pre-Remarketing Distribution Date is not
         a Business Day, then such Pre-Remarketing Distribution Date will be the
         next succeeding Business Day, except if such Business Day is in the
         next succeeding calendar month, such Pre-Remarketing Distribution Date
         will be the immediately preceding Business Day.

         All percentages resulting from any calculations on the Securities will
         be rounded, if necessary, to the nearest one hundred-thousandth of a
         percentage point, with five one-millionths of a percentage point
         rounded upward (e.g., 9.876545% (or .09876545) being rounded to
         9.87655% (or .0987655)), and all dollar amounts used in or resulting
         from such calculation will be rounded to the nearest cent (with
         one-half cent being rounded upward).

                  (c) From and including the Remarketing Settlement Date on
         which Replacement Securities are issued, Distributions on the
         Replacement Securities and on the Common Securities will be payable
         quarterly in arrears (i) on February 12, May 12, August 12 and November
         12 of each year, commencing on such Remarketing Settlement Date and
         (ii) on the Mandatory Redemption Date (each, a "DISTRIBUTION DATE"),
         and will accumulate from the most recent date to which Distributions
         have been paid or, if no Distributions have been paid, from and
         including such Remarketing Settlement Date, to but excluding the
         related Distribution Date, except as otherwise described below. The
         amount of Distributions payable for any quarterly period shall be
         computed on the basis of a 360-day year of twelve 30-day months. Except
         as provided in the last sentence of this paragraph, the amount of
         Distributions payable for any period shorter than a full quarterly
         period for which Distributions are

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         computed will be computed on the basis of the actual number of days
         elapsed per 30-day month. If a Distribution Date is not a Business Day,
         then such Distribution Date will be postponed to the next succeeding
         Business Day (and without any interest or other payment in respect of
         any such delay); provided, that if such Business Day is in the next
         succeeding calendar month, such Distribution Date will be the
         immediately preceding Business Day.

                   (d) Distributions on the Securities will be payable to the
         Holders thereof as they appear on the books and records of the Trust on
         the fifteenth day prior to each Pre-Remarketing Distribution Date or
         Distribution Date, as the case may be. Subject to any applicable laws
         and regulations and the provisions of the Agreement, each such payment
         in respect of the Preferred Securities will be made in respect of any
         global certificate representing Preferred Securities, to the Depository
         (or other applicable Depository), which shall credit the relevant
         accounts at the Depository (or such other Depository) on the applicable
         payment dates, or in respect of Preferred Securities in certified form,
         by check mailed to the address of the Holder entitled thereto as such
         address shall appear on the register; provided that at the written
         request of any Holder of at least $10,000,000 aggregate Liquidation
         Amount of Preferred Securities received by the Property Trustee not
         later than the fifteenth day prior to the applicable Pre-Remarketing
         Distribution Date or Distribution Date, Distributions accrued on such
         Preferred Securities will be payable by wire transfer within the
         continental United States in immediately available funds to the bank
         account number of such holder specified in such request. The relevant
         record dates for the Common Securities shall be the same as the record
         dates for the Preferred Securities. Distributions payable on any
         Securities that are not punctually paid on any Distribution Date, as a
         result of the Subordinated Note Issuer having failed to make a payment
         under the Subordinated Notes, will cease to be payable to the Holder on
         the relevant record date, and such defaulted Distributions will instead
         be payable to the Person in whose name such Securities are registered
         on the special record date or other specified date determined in
         accordance with the Indenture.

                   (e) The Distribution Rate on the Securities (as well as the
         interest rate on the Subordinated Notes) shall be reset in the manner
         provided in Section 6.03 of the Agreement and in the Indenture.

                   (f) In the event that there is any money or other property
         held by or for the Trust that is not accounted for hereunder, such
         property shall be distributed Pro Rata (as defined herein) among the
         Holders of the Securities."

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         SECTION 2.03. Amendment of Securities. Each Holder of Common Securities
and each Holder of Preferred Securities (by signing a separate consent to this
Amendment) agrees to surrender the certificates representing the Securities to
the Property Trustee in exchange for new certificates reflecting the amended
terms provided for in this Amendment in the forms set forth as Exhibits A-1 and
A-2 attached hereto. Such replacement certificates shall be executed by an
Administrative Trustee, and authenticated (in the case of Preferred Securities)
and delivered by the Property Trustee to such Holders upon surrender to the
Property Trustee of the old certificates. The surrendered certificates shall be
canceled by the Property Trustee and shall no longer be outstanding.

                                    ARTICLE 3

         SECTION 3.01. Remarketing of Preferred Securities. (a) Section 4.03(e)
of the Trust Agreement is hereby amended to read in its entirety as follows:

                  "(e) negotiate the terms of, enter into, sign on behalf of the
         Trust and deliver the Purchase Agreement, in the form of Exhibit C,
         providing for the sale of the Preferred Securities, the Remarketing
         Agreement, providing for the Remarketing of the Preferred Securities,
         or under certain circumstances, the Subordinated Notes, and the
         Secondary Purchase Agreement providing for the resale of the Preferred
         Securities."

         (b) Article 6 of the Trust Agreement is hereby amended to read in its
entirety as follows:

                                   "ARTICLE 6

                     DISTRIBUTIONS; RESET RATE; REMARKETING

         SECTION 6.01. Distributions. Holders shall receive Distributions in
accordance with the applicable terms of the relevant Holder's Securities.
Distributions shall be made on the Securities in accordance with the respective
terms and preferences set forth below and in Annex I. If and to the extent that
the Subordinated Note Issuer makes a payment of interest, premium and/or
principal on the Subordinated Notes held by the Property Trustee (the amount of
any such payment being a "PAYMENT AMOUNT"), the Property Trustee shall and is
directed, to the extent funds are available for that purpose, to make a
distribution (a "DISTRIBUTION") of the Payment Amount to Holders.

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<PAGE>   8
         SECTION 6.02.  Remarketing Procedures.

                  (a) (i) Subject to Section 6.04, the Holders of a Majority in
         Liquidation Amount of the Securities, acting together as a single class
         (the "REQUESTING HOLDERS") have the right to require Remarketing of the
         Preferred Securities at any time. The Requesting Holders may exercise
         this right by delivering a written notice to the Remarketing Agent at
         any time requesting a Remarketing of the Preferred Securities. Upon the
         receipt of such notice, the Remarketing Agent shall immediately deliver
         a written notice to the Sponsor on behalf of the Requesting Holders
         (the "REMARKETING NOTICE"). If the Requesting Holders exercise their
         right to require the Remarketing of the Preferred Securities, the Reset
         Date shall be the sixth Business Day (the "EXPECTED RESET DATE") after
         the date on which the Remarketing Notice is received by the Sponsor.

                  (ii)  Notwithstanding Section 6.02(a)(i):

                           (A) the Sponsor may, by notice to the Remarketing
                  Agent, direct that the Reset Date be delayed if the Sponsor
                  believes it will be unable to meet the conditions to
                  Remarketing in the absence of such a delay; and

                           (B) the Remarketing Agent may, by notice to the
                  Sponsor, direct that the Reset Date be delayed if the
                  Remarketing Agent believes that a Remarketing will not be
                  successful in the absence of such a delay;

         provided that the Sponsor and the Remarketing Agent, in either such
         event, will use their reasonable best efforts to establish a delayed
         Reset Date that is within five Business Days after the Expected Reset
         Date, but in no event later than the 15th Business Day following the
         date on which the related Remarketing Notice was received, or the 20th
         Business Day in the case of a Renewed Remarketing (as hereinafter
         defined) to which the provisions of Section 6.04 are applicable (as
         applicable, the "FINAL RESET DATE").

                  (iii) If the Sponsor and the Remarketing Agent have not
         agreed, on or prior to the sixth Business Day preceding the Final Reset
         Date, to a Reset Date that is not later than the Final Reset Date, a
         Failed Remarketing shall be deemed to have occurred.

                  (iv) Notwithstanding the provisions of this Article 6, upon
         receipt of a Remarketing Notice the Sponsor shall have the right, in
         its sole discretion, to elect to pay the aggregate Liquidation Amount
         of and

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<PAGE>   9
         accumulated and unpaid Distributions on the Preferred Securities,
         rather than proceed with the Remarketing. The Sponsor shall make such
         election by sending written notice, within five Business Days after the
         receipt of the Remarketing Notice, to the Remarketing Agent and the
         Property Trustee. If the Sponsor makes such election, it shall pay the
         aggregate Liquidation Amount of and accumulated and unpaid
         Distributions on the Preferred Securities to the Holders thereof on the
         date eight Business Days after receipt of the Remarketing Notice.

                   (b) The Sponsor shall, by notice to the Remarketing Agent no
         later than five Business Days prior to the Reset Date, select and
         specify three Reference Corporate Dealers. By 3:00 p.m., New York City
         time, on the Reset Date, the Remarketing Agent shall request Bids from
         such Reference Corporate Dealers. The Remarketing Agent or an Affiliate
         or Associated Person thereof (any such person, an "AFFILIATED BIDDER")
         may, at its option, also enter a Bid. The Remarketing Agent shall
         disclose to the Sponsor the Bids obtained and determine the lowest Bid
         Rate (the "WINNING BID RATE") from among the Bids obtained on the Reset
         Date. By approximately 4:30 p.m., New York City time, on the Reset
         Date, the Remarketing Agent shall notify the Sponsor and the Property
         Trustee of the Winning Bid Rate. If on a Reset Date, Bids are not
         submitted by at least two Reference Corporate Dealers, or if the lowest
         Bid submitted would result in a Winning Bid Rate in excess of the rate
         permitted by applicable law, such Remarketing shall be deemed to be a
         Failed Remarketing on the corresponding Remarketing Settlement Date.
         The Winning Bid Rate determined by the Remarketing Agent, absent
         manifest error, shall be binding and conclusive upon the Holders of the
         Trust Securities, the Sponsor and the Trust.

                   (c) On the Reset Date, the Remarketing Agent shall designate
         as the Secondary Purchaser (the "SECONDARY PURCHASER") the Reference
         Corporate Dealer providing the Bid containing the Winning Bid Rate. If
         the Winning Bid Rate is specified in the Bids submitted by two or more
         bidders, the Remarketing Agent shall, in consultation with the Sponsor,
         designate one of such bidders as the Secondary Purchaser.

                   (d) On the Reset Date, the Secondary Purchaser shall enter
         into a Secondary Purchase Agreement for the purchase by such Secondary
         Purchaser at the Remarketing Price of the aggregate Liquidation Amount
         of the Preferred Securities, with a Distribution Rate equal to the
         Winning Bid Rate and with a Mandatory Redemption Date on the Remarketed
         Redemption Date.

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                   (e) If a Remarketing has occurred pursuant to this Section
         6.02 but settlement of the purchase and sale of the Preferred
         Securities does not occur on the corresponding Remarketing Settlement
         Date, then, unless the provisions of Section 6.04 with respect to a
         Renewed Remarketing shall apply, a Failed Remarketing shall be deemed
         to have occurred on such Remarketing Settlement Date.

                   (f) At the time and in the manner specified in the Secondary
         Purchase Agreement, the Secondary Purchaser shall pay on the
         Remarketing Settlement Date to the Remarketing Agent on behalf of the
         Holders of the Preferred Securities, an amount of cash equal to the
         Remarketing Price.

                   (g) Unless otherwise agreed among the Remarketing Agent, the
         Paying Agent and any Former Holder, the Remarketing Agent shall pay the
         Remarketing Price to the Paying Agent, acting solely as agent for the
         Former Holders, and the Paying Agent shall promptly pay such amounts to
         the Former Holders on the Remarketing Settlement Date in the manner
         specified in Section 5(g) of Annex I hereto for payments with respect
         to redemptions of the Preferred Securities. Any amounts held by the
         Paying Agent for payment to the Former Holders shall not be property of
         the Trust.

                   (h) The obligation of the Remarketing Agent to make payment
         to the Former Holders in connection with the Remarketing shall be
         limited to the extent that the Secondary Purchaser has delivered the
         Remarketing Price therefor to the Remarketing Agent.

                   (i) Any outstanding Preferred Securities purchased on the
         Remarketing Settlement Date shall be deemed to be transferred to the
         Secondary Purchaser and shall be replaced in the manner provided in
         Section 6.02(j). After the Remarketing Settlement Date (except in the
         event of (y) a Failed Remarketing or (z) a failure by the Trust to pay
         on the Remarketing Settlement Date all accrued and unpaid Distributions
         (including any Additional Distributions) to such Remarketing Settlement
         Date), (A) the Trust shall make no further payments to, and the Trust
         shall have no further obligations under this Agreement in respect of,
         the Holders of such replaced Preferred Securities (the "FORMER
         HOLDERS"), (B) the Trust shall only be obligated to make payments to
         the Holders of Replacement Securities and (C) the Preferred Securities
         of the Former Holders shall no longer represent an obligation of or
         interest in the Trust but shall only represent a right to receive the
         proceeds of the Remarketing from the Paying Agent.

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                   (j) The Sponsor shall cause replacement certificates
         evidencing the remarketed Preferred Securities (the "REPLACEMENT
         SECURITIES") to be executed by an Administrative Trustee on behalf of
         the Trust and authenticated by the Property Trustee in accordance with
         the provisions of Section 7.03. The Replacement Securities shall be
         delivered to the purchaser or purchasers of the remarketed Preferred
         Securities in accordance with the terms of the Secondary Purchase
         Agreement.

         SECTION 6.03. Reset of Distribution Rate and Mandatory Redemption Date.
         From and including the Remarketing Settlement Date on which Replacement
         Securities are issued, the Distribution Rate on the Securities shall be
         the Winning Bid Rate and the Mandatory Redemption Date shall be the
         Remarketed Redemption Date.

         SECTION 6.04. Renewed Remarketing. If a Remarketing has occurred
         pursuant to Section 6.02 that would be a Failed Remarketing pursuant to
         Section 6.02(e), because the purchase and sale of the Preferred
         Securities do not take place on the corresponding Remarketing
         Settlement Date, and such failure, in the good faith determination of
         the Remarketing Agent, results from facts or circumstances other than
         the action or inaction of the Sponsor, then the provisions of Section
         6.02 shall apply to a second remarketing (a "RENEWED REMARKETING") of
         the Preferred Securities, except that the Expected Reset Date shall be
         the sixth Business Day following such corresponding Remarketing
         Settlement Date; provided that upon the occurrence of a Failed
         Remarketing pursuant to Section 6.02(e), only one Renewed Remarketing
         may occur pursuant to this Section 6.04, and no Renewed Remarketing
         shall occur after the Final Reset Date.

         SECTION 6.05. Failed Remarketing. The Remarketing Agent shall give
         notice of any Failed Remarketing by 4:00 p.m., New York City time, on
         the date such Failed Remarketing occurs or is deemed to have occurred
         to the Sponsor and the Property Trustee.

         SECTION 6.06. Payment of Taxes, Duties, Etc. of the Trust. Upon receipt
         under the Subordinated Notes of Additional Interest, the Property
         Trustee shall promptly pay from such Additional Interest any taxes,
         duties or governmental charges of whatever nature (other than
         withholding taxes) imposed on the Trust by the United States or any
         other taxing authority."

                                       11
<PAGE>   12
                  (c) The following Section 3 is hereby inserted into Annex I:

                  "3. Remarketing.

         The Preferred Securities shall be remarketed in accordance with the
         provisions of Article 6 of the Agreement.

         FROM AND AFTER THE REMARKETING SETTLEMENT DATE ON WHICH REPLACEMENT
         SECURITIES ARE ISSUED, THIS CERTIFICATE SHALL REPRESENT ONLY THE RIGHT
         TO RECEIVE THE REMARKETING PRICE, AS PROVIDED IN THE AGREEMENT (AS
         DEFINED BELOW), AND SHALL NO LONGER REPRESENT AN OBLIGATION OF OR
         INTEREST IN THE TRUST."

                                    ARTICLE 4

         SECTION 4.01. Ratification of the Trust Agreement; this Amendment. The
Trust Agreement is in all respects ratified and confirmed, and this Amendment
shall be deemed part of the Trust Agreement in the manner and to the extent
herein and therein provided. The provisions of this Amendment shall supersede
the provisions of the Trust Agreement to extent the Trust Agreement is
inconsistent herewith.

         SECTION 4.02. Trustees Not Responsible for Recitals. The recitals
herein contained are made by the Sponsor and not by the Trustees, and the
Trustees assumes no responsibility for the correctness thereof. The Trustees
make no representation as to the validity or sufficiency of this Amendment.

         SECTION 4.03. Governing Law. This Amendment and the rights of the
parties hereunder shall be governed by and construed in accordance with the laws
of the State of Delaware, and all rights and remedies shall be governed by such
laws, without regard to its principles of conflicts of laws.

         SECTION 4.04. Severability. If any provision in the Trust Agreement or
this Amendment shall be invalid, illegal or unenforceable, the validity,
legality and enforceability of the remaining provisions shall not in any way be
affected or impaired thereby.

         SECTION 4.05. Counterparts. The parties may sign any number of copies
of this Amendment. Each signed copy shall be an original, but all of them
together represent the same agreement. Any signed copy shall be sufficient proof
of this Amendment.

                                       12
<PAGE>   13
         SECTION 4.06. Terms Defined. All terms defined elsewhere in the Trust
Agreement shall have the same meanings when used herein.

         SECTION 4.07. Waiver of Tax Opinion. The parties hereto (including the
Holder of the Preferred Securities by its separate consent to this Amendment)
waive the requirement set out in Section 8 of Annex I and in Section
3.07(a)(vii)(D)(2) of the Trust Agreement for a reasoned Opinion of Counsel of
independent tax counsel.

                                       13
<PAGE>   14
         IN WITNESS WHEREOF, the parties have signed this Amendment as of the
date and year first above written.

                           -----------------------------------------------

                           Israel J. Floyd, not in his individual
                           capacity but solely as Administrative Trustee
                           of the Trust

                           -----------------------------------------------
                           Michael J. Scott, not in his individual
                           capacity but solely as Administrative Trustee
                           of the Trust

                           -----------------------------------------------
                           Stuart C. Shears, not in his individual
                           capacity but solely as Administrative Trustee
                           of the Trust

                           -----------------------------------------------
                           HERCULES INCORPORATED, as Sponsor and Holder
                           of the Common Securities

                           -----------------------------------------------
                           By:
                                  Name:
                                  Title:

                           -----------------------------------------------
                           THE CHASE MANHATTAN BANK, not in its
                           individual capacity, but solely as Property
                           Trustee of the Trust

                           -----------------------------------------------
                           By:
                                  Name:
                                  Title:
<PAGE>   15
                                                                     EXHIBIT A-1

                     FORM OF PREFERRED SECURITY CERTIFICATE

                         PREFERRED SECURITY CERTIFICATE
                     (prior to Remarketing Settlement Date)

THE SECURITIES EVIDENCED HEREBY HAVE NOT BEEN REGISTERED UNDER THE U.S.
SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"), AND, ACCORDINGLY, MAY
NOT BE OFFERED OR SOLD EXCEPT AS SET FORTH IN THE FOLLOWING SENTENCE. BY ITS
ACQUISITION HEREOF, THE HOLDER (1) REPRESENTS THAT IT IS A "QUALIFIED
INSTITUTIONAL BUYER" (AS DEFINED IN RULE 144A UNDER THE SECURITIES ACT), (2)
AGREES THAT IT WILL NOT PRIOR TO THE EXPIRATION OF THE HOLDING PERIOD APPLICABLE
TO SALES OF THE SECURITIES EVIDENCED HEREBY UNDER RULE 144(K) UNDER THE
SECURITIES ACT (OR ANY SUCCESSOR PROVISION) RESELL OR OTHERWISE TRANSFER THE
SECURITIES EVIDENCED HEREBY EXCEPT (A) TO HERCULES INCORPORATED OR ANY
SUBSIDIARY THEREOF, (B) TO A QUALIFIED INSTITUTIONAL BUYER IN COMPLIANCE WITH
RULE 144A UNDER THE SECURITIES ACT OR (C) TO A SECONDARY PURCHASER (AS DEFINED
IN THE AMENDED AND RESTATED TRUST AGREEMENT OF HERCULES TRUST V DATED AS OF
NOVEMBER 12, 1998 (AS AMENDED FROM TIME TO TIME, THE "TRUST AGREEMENT")) THAT
HAS ENTERED INTO A SECONDARY PURCHASE AGREEMENT (AS DEFINED IN THE TRUST
AGREEMENT) WITH THE TRUST, (3) AGREES THAT IT WILL DELIVER TO EACH PERSON TO
WHOM THE SECURITIES EVIDENCED HEREBY ARE TRANSFERRED A NOTICE SUBSTANTIALLY TO
THE EFFECT OF THIS LEGEND AND (4) AGREES, WITH RESPECT TO ANY TRANSFER OCCURRING
PRIOR TO THE REMARKETING DATE ON WHICH REPLACEMENT SECURITIES ARE ISSUED, TO
PROVIDE TO THE PROPERTY TRUSTEE A DULY EXECUTED CERTIFICATE SUBSTANTIALLY TO THE
EFFECT OF CLAUSES (1), (2) AND (3), ABOVE. THIS LEGEND WILL BE REMOVED AFTER THE
EXPIRATION OF THE HOLDING PERIOD APPLICABLE TO THE SALES OF THE SECURITIES
EVIDENCED HEREBY UNDER RULE 144(K) UNDER THE SECURITIES ACT.

FROM AND AFTER THE REMARKETING SETTLEMENT DATE ON WHICH REPLACEMENT SECURITIES
ARE ISSUED, THIS CERTIFICATE SHALL REPRESENT ONLY THE RIGHT TO RECEIVE THE
REMARKETING PRICE, AS PROVIDED IN THE AGREEMENT (AS DEFINED BELOW), AND SHALL NO
LONGER REPRESENT AN OBLIGATION OF OR INTEREST IN THE TRUST.

                                     A-1-1
<PAGE>   16
Certificate Number                                Number of Preferred Securities
         PS-03                                              200,000

                                                           CUSIP NO. __________

                   Certificate Evidencing Preferred Securities

                                       of

                                HERCULES TRUST V

                     Auction Rate Reset Preferred Securities
               (Liquidation Amount $1,000 per Preferred Security)

         HERCULES TRUST V, a statutory business trust created under the laws of
the State of Delaware (the "TRUST"), hereby certifies that NMS Services, Inc.
(the "HOLDER") is the registered owner of 200,000 securities of the Trust
representing undivided beneficial interests in the assets of the Trust
designated the Auction Reset Rate Preferred Securities (Liquidation Amount
$1,000 per Preferred Security) (the "PREFERRED SECURITIES"). This Preferred
Security is transferable on the books and records of the Trust, in person or by
a duly authorized attorney, upon surrender of this certificate duly endorsed and
in proper form for transfer. The designation, rights, privileges, restrictions,
preferences and other terms and provisions of the Preferred Securities
represented hereby are issued and shall in all respects be subject to the
provisions of the Amended and Restated Trust Agreement of the Trust dated as of
November 12, 1998, as the same has been and may be amended from time to time,
including the designation of the terms of the Preferred Securities as set forth
in Annex I to the Agreement (the "AGREEMENT"). Capitalized terms used but not
defined herein shall have the meaning given them in the Agreement. The Sponsor
will provide a copy of the Agreement, the Preferred Securities Guarantee and the
Indenture to a Holder without charge upon written request to the Trust at its
principal place of business.

         Upon receipt of this certificate, the Holder is bound by the Agreement
and is entitled to the benefits thereunder and to the benefits of the Preferred
Securities Guarantee to the extent provided therein.

         By acceptance, the Holder agrees to treat, for United States Federal
income tax purposes, the Subordinated Notes as indebtedness and the Preferred
Securities as evidence of indirect beneficial ownership in the Subordinated
Notes.

                                     A-1-2
<PAGE>   17
         IN WITNESS WHEREOF, the Trust has executed this certificate this 9th
day of February, 2000.

                                         HERCULES TRUST V

                                         By:
                                             ----------------------------------
                                             Name: Israel J. Floyd
                                             Title:   Administrative Trustee

         PROPERTY TRUSTEE'S CERTIFICATE OF AUTHENTICATION

         This is one of the Preferred Securities referred to in the
within-mentioned Agreement.

Dated:   February 9, 2000

                                         THE CHASE MANHATTAN BANK,
                                         as Property Trustee

                                         By:
                                             -----------------------------------
                                             Authorized Signatory
<PAGE>   18
                              [REVERSE OF SECURITY]

           (a) "DISTRIBUTIONS" with respect to the Liquidation Amount of $1,000
per Preferred Security (the "LIQUIDATION AMOUNT") of each Security will accrue
and be payable at a rate (the "DISTRIBUTION RATE") (such rate being the rate of
interest payable on the Subordinated Notes to be held by the Property Trustee)
per annum equal to

                            (i) from and including November 12, 1998 to but
                  excluding February 9, 2000, LIBOR plus 175 basis points;

                           (ii) from and including February 9, 2000 to but
                  excluding the earlier of (A) the Remarketing Settlement Date
                  on which Replacement Securities are issued and (B) the date
                  such Security is redeemed, LIBOR plus 150 basis points;

                          (iii) from and including the Remarketing Settlement
                  Date on which Replacement Securities are issued to but
                  excluding the date such Security is redeemed, the Winning Bid
                  Rate; and

                           (iv) notwithstanding clauses (i), (ii) and (iii)
                  above, if such Security is not redeemed because the
                  Subordinated Note Issuer fails to pay the principal amount of
                  the Subordinated Notes on the date such amount becomes due,
                  then from and including such due date to but excluding the
                  date such Security is redeemed, the applicable Distribution
                  Rate in effect on the due date, compounded quarterly, but only
                  to the extent permitted by applicable law.

Distributions that are not paid when due will bear additional distributions
("ADDITIONAL DISTRIBUTIONS") thereon compounded quarterly at the applicable
Distribution Rate in effect on the due date specified above (to the extent
permitted by applicable law). A Distribution is payable only to the extent that
payments are made in respect of the Subordinated Notes held by the Property
Trustee and to the extent the Property Trustee has funds on hand legally
available therefor.

           (b) Until the Remarketing Settlement Date on which Replacement
Securities are issued, Distributions on the Securities will be payable quarterly
in arrears (i) on February 12, May 12, August 12 and November 12 of each year,
commencing February 12, 1999 and (ii) on such Remarketing Settlement Date (each,
a "PRE-REMARKETING DISTRIBUTION DATE"), and will accumulate from and including
the most recent date to which Distributions have been paid or, if no
Distributions have been paid, from November 12, 1998, to but excluding the
related Pre-Remarketing Distribution Date, except as otherwise described below.

                                     A-1-4
<PAGE>   19
         The Distribution Rate in effect for the period from and including
November 12, 1998 to but excluding February 12, 1999 shall be the rate
determined by the Calculation Agent two London Banking Days prior to November
12, 1998 and shall equal LIBOR plus 175 basis points. The Distribution Rate in
effect from and including February 12, 1999 to but excluding February 9, 2000,
for each quarterly period from and including the immediately preceding
Pre-Remarketing Distribution Date to but excluding the applicable
Pre-Remarketing Distribution Date, shall be determined by the Calculation Agent
two London Banking Days prior to such immediately preceding Pre-Remarketing
Distribution Date (a "DATE OF DETERMINATION") and shall equal LIBOR plus 175
basis points. The Distribution Rate in effect thereafter, for each quarterly
period from and including the immediately preceding Pre-Remarketing Distribution
Date to but excluding the applicable Pre-Remarketing Distribution Date, shall be
determined by the Calculation Agent two London Banking Days prior to such
immediately preceding Pre-Remarketing Distribution Date and shall equal LIBOR
plus 150 basis points. The amount of the Distribution payable on February 12,
2000 shall reflect the pro rata application of the two Distribution Rates
applicable to the calculation period for such Distribution for each day on which
the applicable Distribution Rate was in effect. The amount of Distributions
payable for any quarterly period shall be computed on the basis of a 360-day
year of twelve 30-day months. Except as provided in the last sentence of this
paragraph, the amount of Distributions payable for any period shorter than a
full quarterly period for which Distributions are computed will be computed on
the basis of the actual number of days elapsed per 30-day month. If a
Pre-Remarketing Distribution Date is not a Business Day, then such
Pre-Remarketing Distribution Date will be the next succeeding Business Day,
except if such Business Day is in the next succeeding calendar month, such
Pre-Remarketing Distribution Date will be the immediately preceding Business
Day.

         All percentages resulting from any calculations on the Preferred
Securities will be rounded, if necessary, to the nearest one hundred-thousandth
of a percentage point, with five one-millionths of a percentage point rounded
upward (e.g., 9.876545% (or .09876545) being rounded to 9.87655% (or .0987655)),
and all dollar amounts used in or resulting from such calculation will be
rounded to the nearest cent (with one-half cent being rounded upward).

           (c) From and including the Remarketing Settlement Date on which
Replacement Securities are issued, Distributions on the Replacement Securities
and on the Common Securities will be payable quarterly in arrears (i) on
February 12, May 12, August 12 and November 12 of each year, commencing on such
Remarketing Settlement Date and (ii) on the Mandatory Redemption Date (each, a
"DISTRIBUTION DATE"), and will accumulate from the most recent date to which

                                      A-1-5
<PAGE>   20
Distributions have been paid or, if no Distributions have been paid, from and
including such Remarketing Settlement Date, to but excluding the related
Distribution Date, except as otherwise described below. The amount of
Distributions payable for any quarterly period shall be computed on the basis of
a 360-day year of twelve 30-day months. Except as provided in the last sentence
of this paragraph, the amount of Distributions payable for any period shorter
than a full quarterly period for which Distributions are computed will be
computed on the basis of the actual number of days elapsed per 30-day month. If
a Distribution Date is not a Business Day, then such Distribution Date will be
postponed to the next succeeding Business Day (and without any interest or other
payment in respect of any such delay); provided, that if such Business Day is in
the next succeeding calendar month, such Distribution Date will be the
immediately preceding Business Day.

 Subject to other conditions set forth in the Agreement and the Indenture, the
Property Trustee may, at the direction of the Sponsor, at any time dissolve the
Trust and cause the Subordinated Notes to be distributed to the Holders of the
Securities in liquidation of the Trust or, simultaneously with any redemption of
the Subordinated Notes, cause a Like Amount of the Securities to be redeemed by
the Trust.

This Preferred Security shall be redeemable as provided in the Agreement.

                                     A-1-6
<PAGE>   21
                              ---------------------

                                   ASSIGNMENT

FOR VALUE RECEIVED, the undersigned assigns and transfers this Preferred
Security Certificate to:

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
        (Insert assignee's social security or tax identification number)

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
                    (Insert address and zip code of assignee)

and irrevocably appoints

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
to transfer this Preferred Security Certificate on the books of the Trust. The
agent may substitute another to act for him or her.

Date:
      ------------------------

Signature:
           -------------------
(Sign exactly as your name appears on the other side of this Preferred Security
Certificate)

Signature Guarantee(1):
                       -----------------------------------

--------
(1)      Signature must be guaranteed by an "eligible guarantor institution"
         that is a bank, stockbroker, savings and loan association or credit
         union meeting the requirements of the Registrar, which requirements
         include membership or participation in the Securities Transfer Agents
         Medallion Program ("STAMP") or such other "signature guarantee program"
         as may be determined by the Registrar in addition to, or in
         substitution for, STAMP, all in accordance with the Securities and
         Exchange Act of 1934, as amended.

                                     A-1-7
<PAGE>   22
                                                                     EXHIBIT A-2

                       FORM OF COMMON SECURITY CERTIFICATE

                           COMMON SECURITY CERTIFICATE

THIS CERTIFICATE IS NOT TRANSFERABLE EXCEPT IN COMPLIANCE WITH APPLICABLE LAW
AND THE PROVISIONS OF THE AMENDED AND RESTATED TRUST AGREEMENT OF HERCULES TRUST
V DATED AS OF NOVEMBER 12, 1998, AS AMENDED FROM TIME TO TIME.

                                     A-2-1
<PAGE>   23
Certificate Number                                  Number of Common Securities
      CS-03                                                  6,200

                    Certificate Evidencing Common Securities

                                       of

                                HERCULES TRUST V

                      Auction Rate Reset Common Securities
                 (Liquidation Amount $1,000 per Common Security)

         HERCULES TRUST V, a statutory business trust created under the laws of
the State of Delaware (the "TRUST"), hereby certifies that Hercules Incorporated
(the "HOLDER") is the registered owner of 6,200 securities of the Trust
representing undivided beneficial interests in the assets of the Trust
designated the Auction Rate Reset Common Securities (Liquidation Amount $1,000
per Common Security) (the "COMMON SECURITIES"). Except as set forth in the
Agreement (as defined herein), the Common Securities are not transferable. The
designation, rights, privileges, restrictions, preferences and other terms and
provisions of the Common Securities represented hereby are issued and shall in
all respects be subject to the provisions of the Amended and Restated Trust
Agreement of the Trust dated as of November 12, 1998, as the same has been and
may be amended from time to time, including the designation of the terms of the
Common Securities as set forth in Annex I to the Agreement (the "AGREEMENT").
Capitalized terms used but not defined herein shall have the meaning given them
in the Agreement. The Sponsor will provide a copy of the Agreement, the Common
Securities Guarantee and the Indenture to a Holder without charge upon written
request to the Trust at its principal place of business.

         Upon receipt of this certificate, the Holder is bound by the Agreement
and is entitled to the benefits thereunder and to the benefits of the Common
Securities Guarantee to the extent provided therein.

         By acceptance, the Holder agrees to treat, for United States Federal
income tax purposes, the Subordinated Notes as indebtedness and the Common
Securities as evidence of indirect beneficial ownership in the Subordinated
Notes.

                                      A-2-2
<PAGE>   24
         IN WITNESS WHEREOF, the Trust has executed this certificate this 9th
day of February, 2000.

                                           HERCULES TRUST V

                                           By: _______________________________
                                               Name: Israel J. Floyd
                                               Title: Administrative Trustee
<PAGE>   25
                          [REVERSE OF COMMON SECURITY]

                (a) "DISTRIBUTIONS" with respect to the Liquidation Amount of
$1,000 per Common Security (the "LIQUIDATION AMOUNT") of each Security will
accrue and be payable at a rate (the "DISTRIBUTION RATE") (such rate being the
rate of interest payable on the Subordinated Notes to be held by the Property
Trustee) per annum equal to

                        (i) from and including November 12, 1998 to but
                  excluding February 9, 2000, LIBOR plus 175 basis points;

                       (ii) from and including February 9, 2000 to but excluding
                  the earlier of (A) the Remarketing Settlement Date on which
                  Replacement Securities are issued and (B) the date such
                  Security is redeemed, LIBOR plus 150 basis points;

                      (iii) from and including the Remarketing Settlement Date
                  on which Replacement Securities are issued to but excluding
                  the date such Security is redeemed, the Winning Bid Rate; and

                       (iv) notwithstanding clauses (i), (ii) and (iii) above,
                  if such Security is not redeemed because the Subordinated Note
                  Issuer fails to pay the principal amount of the Subordinated
                  Notes on the date such amount becomes due, then from and
                  including such due date to but excluding the date such
                  Security is redeemed, the applicable Distribution Rate in
                  effect on the due date, compounded quarterly, but only to the
                  extent permitted by applicable law.

Distributions that are not paid when due will bear additional distributions
("ADDITIONAL DISTRIBUTIONS") thereon compounded quarterly at the applicable
Distribution Rate in effect on the due date specified above (to the extent
permitted by applicable law). A Distribution is payable only to the extent that
payments are made in respect of the Subordinated Notes held by the Property
Trustee and to the extent the Property Trustee has funds on hand legally
available therefor.

         (b) Until the Remarketing Settlement Date on which Replacement
Securities are issued, Distributions on the Securities will be payable quarterly
in arrears (i) on February 12, May 12, August 12 and November 12 of each year,
commencing February 12, 1999 and (ii) on such Remarketing Settlement Date (each,
a "PRE-REMARKETING DISTRIBUTION DATE"), and will accumulate from and including
the most recent date to which Distributions have been paid or, if no
Distributions have been paid, from November 12, 1998, to but excluding the
related Pre-Remarketing Distribution Date, except as otherwise described below.

                                      A-2-4
<PAGE>   26
         The Distribution Rate in effect for the period from and including
November 12, 1998 to but excluding February 12, 1999 shall be the rate
determined by the Calculation Agent two London Banking Days prior to November
12, 1998 and shall equal LIBOR plus 175 basis points. The Distribution Rate in
effect from and including February 12, 1999 to but excluding February 9, 2000,
for each quarterly period from and including the immediately preceding
Pre-Remarketing Distribution Date to but excluding the applicable
Pre-Remarketing Distribution Date, shall be determined by the Calculation Agent
two London Banking Days prior to such immediately preceding Pre-Remarketing
Distribution Date (a "DATE OF DETERMINATION") and shall equal LIBOR plus 175
basis points. The Distribution Rate in effect thereafter, for each quarterly
period from and including the immediately preceding Pre-Remarketing Distribution
Date to but excluding the applicable Pre-Remarketing Distribution Date, shall be
determined by the Calculation Agent two London Banking Days prior to such
immediately preceding Pre-Remarketing Distribution Date and shall equal LIBOR
plus 150 basis points. The amount of the Distribution payable on February 12,
2000 shall reflect the pro rata application of the two Distribution Rates
applicable to the calculation period for such Distribution for each day on which
the applicable Distribution Rate was in effect. The amount of Distributions
payable for any quarterly period shall be computed on the basis of a 360-day
year of twelve 30-day months. Except as provided in the last sentence of this
paragraph, the amount of Distributions payable for any period shorter than a
full quarterly period for which Distributions are computed will be computed on
the basis of the actual number of days elapsed per 30-day month. If a
Pre-Remarketing Distribution Date is not a Business Day, then such
Pre-Remarketing Distribution Date will be the next succeeding Business Day,
except if such Business Day is in the next succeeding calendar month, such
Pre-Remarketing Distribution Date will be the immediately preceding Business
Day.

         All percentages resulting from any calculations on the Common
Securities will be rounded, if necessary, to the nearest one hundred-thousandth
of a percentage point, with five one-millionths of a percentage point rounded
upward (e.g., 9.876545% (or .09876545) being rounded to 9.87655% (or .0987655)),
and all dollar amounts used in or resulting from such calculation will be
rounded to the nearest cent (with one-half cent being rounded upward).

         (c) From and including the Remarketing Settlement Date on which
Replacement Securities are issued, Distributions on the Replacement Securities
and on the Common Securities will be payable quarterly in arrears (i) on
February 12, May 12, August 12 and November 12 of each year, commencing on such
Remarketing Settlement Date and (ii) on the Mandatory Redemption Date (each, a
"DISTRIBUTION DATE"), and will accumulate from the most recent date to which
Distributions have been paid or, if no Distributions have been paid, from and

                                      A-2-5
<PAGE>   27
including such Remarketing Settlement Date, to but excluding the related
Distribution Date, except as otherwise described below. The amount of
Distributions payable for any quarterly period shall be computed on the basis of
a 360-day year of twelve 30-day months. Except as provided in the last sentence
of this paragraph, the amount of Distributions payable for any period shorter
than a full quarterly period for which Distributions are computed will be
computed on the basis of the actual number of days elapsed per 30-day month. If
a Distribution Date is not a Business Day, then such Distribution Date will be
postponed to the next succeeding Business Day (and without any interest or other
payment in respect of any such delay); provided, that if such Business Day is in
the next succeeding calendar month, such Distribution Date will be the
immediately preceding Business Day.

         Subject to other conditions set forth in the Agreement and the
Indenture, the Property Trustee may, at the direction of the Sponsor, at any
time dissolve the Trust and cause the Subordinated Notes to be distributed to
the Holders to the Securities in liquidation of the Trust or, simultaneously
with any redemption of the Subordinated Notes, cause a Like Amount of the
Securities to be redeemed by the Trust.

         This Common Security shall be redeemable as provided in the Agreement.

                                      A-2-6

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