Exhibit
10.5




Joinder
Agreement




SUPPLEMENT
NO. 1 (the “Supplement”) dated as
of May 5, 2008, to the Guarantee Agreement, dated as of February 28, 2008 (as
amended, restated, amended and restated, supplemented or otherwise modified from
time to time, the “Guarantee
Agreement”), among each of the subsidiaries of SOLUTIA INC., a
Delaware corporation (the “Borrower”) listed on
Schedule I
thereto (each such subsidiary individually, a “Subsidiary Guarantor”
and collectively, together with each other Subsidiary that becomes a party
thereto, the “Subsidiary
Guarantors”) in favor of CITIBANK, N.A., as administrative agent for the
Lenders (as defined in the Bridge Credit Agreement referred to below) (in such
capacity, together with its successors in such capacity, the “Administrative
Agent”).




1.
            Reference
      is made to (a) the Credit Agreement dated as of February 28, 2008 (as
      amended, restated, amended and restated, supplemented or otherwise
      modified from time to time, the “Bridge Credit
      Agreement”), among the Borrower, the Administrative Agent, the
      Lenders, and the other agents party thereto and (b) the Indemnity,
      Subrogation and Contribution Agreement, dated as of February 28, 2008, (as
      amended, restated, amended and restated, supplemented or otherwise
      modified from time to time, the “Indemnity, Subrogation
      and Contribution Agreement” and, together with the Guarantee
      Agreement, the “Guarantee
      Documents”), made by the Borrower and the each of the subsidiaries
      of the Borrower listed on Schedule I
      thereto in favor or the Administrative Agent.  Capitalized terms
      used herein and not otherwise defined herein shall have the meanings
      assigned to such terms in the Guarantee
  Agreement.




2.
            The
      Guarantors have entered into the Guarantee Documents in order to induce
      the Lenders to enter into the Bridge Credit Agreement and to induce the
      Lenders to make Loans to the Borrower under the Bridge Credit
      Agreement.




3.
            Pursuant
      to Section 5.15 of the Bridge Credit Agreement, each Subsidiary
      (other than any Excluded Subsidiary) of the Borrower that was not in
      existence or not a Subsidiary on the date of the Bridge Credit Agreement
      is required to enter into the Guarantee Documents upon becoming a
      Subsidiary.  Each undersigned Subsidiary (“New
      Subsidiary”) is executing this Supplement in accordance with the
      requirements of the Bridge Credit Agreement, Guarantee Agreement and
      Indemnity, Subrogation and Contribution Agreement to become a Guarantor
      under the Guarantee Documents.




Accordingly,
the Administrative Agent and each New Subsidiary agree as follows:







SECTION 1.In
accordance with Section 19 of the Guarantee Agreement and Section 14 of the
Indemnity, Subrogation and Contribution Agreement, each New Subsidiary by its
signature below becomes a Guarantor under the Guarantee Documents with the same
force and effect as if originally named therein as a Guarantor and each New
Subsidiary hereby (a) agrees to all the terms and provisions of the Guarantee
Documents applicable to it as a Guarantor thereunder and (b) represents and
warrants that the representations and warranties made by it as a Guarantor
thereunder are true and correct (or true and correct in all material respects if
not otherwise qualified by materiality or a Material Adverse Effect) on and as
of the date hereof (except to the extent that they expressly relate to an
earlier date, in which case they shall be true and correct (or true and correct
in all material respects if not otherwise qualified by materiality or a Material
Adverse Effect) as of such earlier date).  As of the date hereof, each
reference to a Guarantor in the Guarantee Documents shall be deemed to include
each New Subsidiary.  The Guarantee Documents are hereby incorporated
herein by reference.




SECTION
2. Each New
Subsidiary represents and warrants to the Administrative Agent and the Lenders
that this Supplement has been duly authorized, executed and delivered by it and
constitutes its legal, valid and binding obligation, enforceable against it in
accordance with its terms, except that the enforcement thereof may be subject to
bankruptcy, insolvency, reorganization, moratorium or other similar laws now or
hereafter in effect relating to creditors’ rights generally and to general
principles of equity, regardless of whether considered in a proceeding in equity
or at law.




SECTION
3. This
Supplement may be executed in counterparts (and by different parties hereto on
different counterparts), each of which shall constitute an original, but all of
which when taken together shall constitute a single
contract.  Delivery of an executed signature page to this Supplement
by facsimile or other electronic transmission shall be as effective as delivery
of a manually signed counterpart of this Supplement.




SECTION
4. Except as
expressly supplemented hereby, the Guarantee Agreement shall remain in full
force and effect.




SECTION
5. THIS
SUPPLEMENT SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF
THE STATE OF NEW YORK.




SECTION
6. In case
any one or more of the provisions contained in this Supplement should be held
invalid, illegal or unenforceable in any respect, the validity, legality and
enforceability of the remaining provisions contained herein and in the Guarantee
Documents shall not in any way be affected or impaired thereby (it being
understood that the invalidity a particular provision in a particular
jurisdiction shall not in and of itself affect the validity of such provision in
any other jurisdiction).  The parties hereto shall endeavor in
good-faith negotiations to replace the invalid, illegal or unenforceable
provisions with valid provisions the economic effect of which comes as close as
possible to that of the invalid, illegal or unenforceable
provisions.




SECTION
7. All
communications and notices hereunder shall (except as otherwise expressly
permitted herein) be in writing and given as provided in Section 9.01 of
the Bridge Credit Agreement.  All communications and notices hereunder
to any New Subsidiary shall be given to it c/o the Borrower at the Borrower’s
address as provided in Section 9.01 of the Bridge Credit Agreement, with a copy
to the Borrower.




SECTION
8. Each New
Subsidiary agrees to reimburse the Administrative Agent for its reasonable
out-of-pocket expenses in connection with this Supplement, including the
reasonable fees, other charges and disbursements of counsel for the
Administrative Agent in each case in accordance with the terms of the Bridge
Credit Agreement.






[Signature
Page Follows]







IN
WITNESS WHEREOF, each New Subsidiary and the Administrative Agent have duly
executed this Supplement as of the day and year first above
written.





S E
      Investment LLCBy:
            /s/ James A.
      TichenorName:
            James
      A. TichenorTitle:
            Vice
      President and TreasurerAddress:
            575
      Maryville Centre Drive
              St.
      Louis, MO 63141CITIBANK,
      N.A.
              As
      Administrative AgentBy:
            /s/ David
      JaffeName:
            David
      JaffeTitle:
            Director/Vice
      President