Hyperbranched copolymers from AB monomers and C monomers

A process for preparing hyperbranched polymers from AB monomers and C monomers Using a self-constructing approach is disclosed along with the hyperbranched polymers of a living-like character produced by such process.

BACKGROUND OF THE INVENTION 
Structurally, polymers are classified as either linear or branched wherein 
the term "branched" generally means that the individual molecular units of 
the branches are discrete from the polymer backbone, yet may have the same 
chemical constitution as the polymer backbone. Thus, regularly reacting 
side groups which are inherent in the monomeric structure and are of 
different chemical constitution than the polymer backbone are not 
considered as "branches"; that is, for example, the methyl groups pendant 
on a polydimethylsiloxane chain or a pendant aryl group in a polystyrene 
are not considered to be branches of such polymers. All descriptions of 
branching and backbone in the present application are consistent with this 
meaning. 
The simplest branched polymers are the comb branched polymers wherein a 
linear backbone bears one or more essentially linear pendant side chains. 
This simple form of branching, often called comb branching, may be regular 
wherein the branches are distributed in uniform fashion on the polymer 
backbone or irregular wherein the branches are distributed in non-uniform 
or random fashion on the polymer backbone. An example of regular comb 
branching is a comb branched polystyrene as described by T. Altores et al. 
in J. Polymer Sci., Part A, Vol. 3 4131-4151 (1965) and an example of 
irregular comb branching is illustrated by graft copolymers as described 
by Sorenson et Preparative Methods of Polymer Chemistry, 2nd Ed., 
Interscience Publishers, 213-214 (1968). 
Another type of branching is exemplified by cross-linked or network 
polymers wherein the polymer chains are connected through the use of 
bi-functional compounds; e.g., polystyrene molecules bridged or 
cross-linked with divinylbenzene. In this type branching, many of the 
individual branches are not linear in that each branch may itself contain 
side chains pendant from a linear chain and it is not possible to 
differentiate between the backbone and the branches. More importantly, in 
network branching, each polymer macromolecule (backbone) is cross-linked 
at two or more sites to other polymer macromolecules. Also the chemical 
constitution of the cross-linkages may vary from that of the polymer 
macromolecules. In this cross-linked or network branched polymer, the 
various branches or cross-linkages may be structurally similar (called 
regular cross-linked) or they may be structurally dissimilar (called 
irregularly cross-linked). An example of regular cross-linked polymers is 
a ladder-type poly(phenylsisesquinone) [sic] 
{poly-(phenylsilsesquioxane)}. Sogah et al, in the background of U.S. Pat. 
No. 4,544,724, discusses some of these types of polymers and gives a short 
review of the many publications and disclosures regarding them. U.S. Pat. 
No. 4,435,548, discusses branched polyamidoamines; U.S. Pat. Nos. 
4,507,466, 4,558,120, 4,568,737, 4,587,329, 4,713,975, 4,871,779, and 
4,631,337 discuss the preparation and use of dense star polymers, and U.S. 
Pat. Nos. 4,737,550 and 4,857,599 discuss bridged and other modified dense 
star polymers. 
Other structural configurations of macromolecular materials that have been 
disclosed include star/comb-branched polymers, such disclosure being found 
in U.S. Pat. Nos. 4,599,400 and 4,690,985, and rod-shaped dendrimer 
polymers are disclosed in U.S. Pat. No. 4,694,064. 
Hutchins et al, in U.S. Pat. Nos. 4,847,328 and 4,851,477, deal with hybrid 
acrylic-condensation star polymers and Joseph et al, in U.S. Pat. Nos. 
4,857,615, 4,857,618, and 4,906,691, with condensed phase polymers having 
regularly, or irregularly, spaced polymeric branches essentially on the 
order of a comb structure macromolecules. 
M. Gauthier et al, Macromolecules, 24, 4548-4553 (1991) discloses uniform 
highly branched polymers produced by stepwise anionic grafting. M. Suzuki 
et al, Macromolecules, 25, 7071-2 (1992) describes palladium-catalyzed 
ring-opening polymerization of cyclic carbamate to produce hyperbranched 
dendritic polyamines. Macromolecules, 24, 1435-1438 (1991) discloses 
comb-burst dendrimer topology derived from dendritic grafting. U.S. Pat. 
No. 5,041,516 discloses other dendritic macromolecules. 
The various architectures of these macromolecules results in a variety of 
end product uses. It is desirable to produce macromolecules that are 
hyperbranched (containing 2 or more generations of branching) so as to 
enable the production of highly functional macromolecules. Increasing the 
functionality of a macromolecule at a multiplicity of sites within the 
macromolecule can make it a much more useful molecule. 
Dendrimers and hyperbranched polymers have received much attention recently 
due to their unusual structural features and properties. In the early 
1950's, Flory, J. Am. Chem. Soc., 74, 2718 (1952) discussed the potential 
of AB.sub.2 monomers, in which A and B are different reactive groups which 
react with each other to form a chemical bond, for the formation of highly 
branched polymers. However, the formation of high molecular weight 
hyperbranched polymers from AB.sub.2 monomers containing one group of type 
A and two of type B was not accomplished until 1988 when Kim et al., 
Polym. Prep., 29(2), 310 (1988) (U.S. Pat. No. 4,857,630) reported the 
preparation of hyperbranched polyphenylene. 
Numerous other hyperbranched polymers have been reported since that time by 
Hawker et al., J. Am. Chem. Soc., 113, 4583, (1991); Uhrich et al, 
Macromolecules, 25, 4583 (1994); Turner et al, Macromolecules, 27, 1611 
(1994); and others. See also U.S. Pat. Nos. 5,196,502; 5,225,522; and 
5,214,122. All of these hyperbranched polymers are obtained by 
polycondensation processes involving AB.sub.2 monomers. In general, these 
hyperbranched polymers have irregularly branched structures with high 
degrees of branching between 0.2 and 0.8. 
The degree of branching DB of an AB.sub.2 hyperbranched polymer has been 
defined by the equation DB=(1-f) in which f is the mole fraction of 
AB.sub.2 monomer units in which only one of the two B groups has reacted 
with an A group. 
In contrast to hyperbranched polymers, regular dendrimers are regularly 
branched, macromolecules with a branch point at each repeat unit. Unlike 
hyperbranched polymers that are obtained via a polymerization reaction, 
most regular dendrimers are obtained by a series of stepwise coupling and 
activation steps. Examples of dendrimers include the polyamidoamide 
(PAMAM) Starburst.TM. dendrimers of Tomalia et al, Polym. J., 17, 117 
(1985) or the convergent dendrlmers of Hawker et al, J. Am. Chem. Soc., 
112, 7638 (1990). 
Recently, some highly branched polymers have been prepared in multistep 
processes involving a graft on graft technique that leads to a dramatic 
increase in molecular weight as a result of successive stepwise grafting 
steps. Examples of such polymers are the Combburst.TM. polymers of Tomalia 
et al., Macromolecules, 24, 1435 (1991); U.S. Pat. No. 4,694,064; and the 
"arborescent" polymers of Gauthier et al., Macromolecules, 24, 4548 (1991) 
and Macromolecular Symposia, 77, 43 (1994). 
The preparation of hyperbranched polymers by a chain growth vinyl 
polymerization has not been accomplished previously. 
DISCLOSURE OF THE INVENTION 
Accordingly, the present invention is directed to a process for preparing 
highly branched or "hyperbranched" polymers by a chain-growth 
polymerization process involving the copolymerization reaction of an AB 
monomer with a C monomer. The AB monomers that may be used contain two 
reactive groups A and B, which react independently of each other within a 
molecule, i.e., reaction onto A is not required to trigger the reaction of 
B. The A group is a polymerizable vinyl group that is able to react with 
an active moiety such as an anion, a cation, or a conventional initiating 
or propagating moiety of the type well known in the art of vinyl 
polymerization such as those described in Principles of Polymerization, 
3rd Ed. by G. Odian (Wiley) to produce anew activated group A* that is 
capable of further reaction with any A-containing moiety present in the 
polymerization mixture to give an A'-A* unit in which A' is an inactive 
(non-reactive) group derived from A that acts as a building block of the 
final polymer. 
The B group is preferably a reactive group that can be activated by an 
activator such as one or more external activator molecules like (i) alkyl 
aluminum halide, e.g. EtAlCl.sub.2 and Et.sub.1.5 AlCl.sub.1.5, (ii) 
SnCl.sub.4 ; (iii) SnCl.sub.4 combined with Bu.sub.4 NCl, (iv) HI combined 
with I.sub.2, or (v) CH.sub.3 SO.sub.3 H combined with Bu.sub.4 NCl and 
SnCl.sub.4 or SnCl.sub.4 combined with 2,6-di-tert-butylpyridine. Other 
external activators include Lewis acids, bases such as hydroxides, butyl 
lithium, amines and carbanions, heat, light, or radiation, which activate 
to produce an anion, cation, or conventional initiating or propagating 
moiety well known in the art of vinyl polymerization such as those 
described in Aoshima et al, J. Polymer Science, A, Polymer Chemistry, 32, 
1729 (1994) or in Ishihama et. al. Polymer Bulletin 24 201 (1990) or in 
Higashimura et. al. Macromolecules 26, 744 (1993) or in "Polymer 
Synthesis", 2nd Ed, by P. Rempp and E. Merrill (Huthig & Wepf). Once 
activated, B becomes B*. Any B* group present in the polymerization 
mixture may react with any A-containing moiety present in the 
polymerization mixture to afford a B'-A* unit in which B' is an inactive 
group derived from B that acts as a building block of the final polymer. 
The C monomer contains a polymerizable group that can be initiated by A*, 
B*, as well as by another suitable initiator such as alkyl aluminum 
halides, Lewis acids, bases, heat, light, and radiation. Once reaction of 
C with an A* or a B* unit or another initiator has occurred, C becomes a 
new activated C* group that is capable of further reaction with any A 
containing moiety present in the system, as well as with any C monomer 
remaining in the system. For example, further reaction of a moiety 
containing C* with an A containing moiety affords a new product with a 
C'-A, unit in which C' is an inactive (non-reactive) group derived from C 
that acts as a building block of the final polymer. Similarly, further 
reaction of a moiety containing C* with a C monomer unit affords a new 
product with a C'-C* unit in which C' is an inactive group derived from C 
that acts as a building block of the final polymer. 
The reactive moiety of the C monomer, such as a vinyl ether group, may be 
exactly the same as the A moiety of the AB monomer which is presently the 
preferred embodiment, or it may be another type of vinyl group having a 
reactivity or polymerizability similar to that of A with respect to B* or 
A*. 
This invention represents a new concept whereby hyperbranched polymers are 
obtained not from an AB.sub.2 type monomer as described in the prior art, 
but from an AB monomer in combination with a C monomer. The process 
comprises "self-constructing" polymers that contain throughout their 
growth a single polymerizable group A and a multiplicity of propagating 
species such as A* or B*, for example, a carbenium ion. 
In the process of the present invention, the "monomer" consists of 
polymerizable initiator molecules (AB molecules) that are activated by an 
external event to produce activated polymerizable initiator molecules (AB* 
molecules). Not all AB molecules need to be activated to A-B* since both 
A* and B* can add to any available A group, and any B group that remains 
inactivated may become activated later as a result of an exchange process. 
These molecules grow by adding to any available polymerizable A or C group 
present in the reaction mixture in a process that involves successive and 
repeated couplings of growing polymer chains with A-containing moieties 
and C-containing moieties, including the growing chains themselves, until 
the concentration of A and C groups is so reduced that the polymerization 
process no longer proceeds at an appreciable rate. Alternately, the 
polymerization of the C monomer may be started first followed by addition 
of the AB monomer to produce a hyperbranched polymer. 
The process of the present invention leads to a growing chain and therefore 
a final polymer containing not only units derived from the AB monomer but 
also units derived from the C monomer. Compared to a process involving 
homopolymerization of only AB monomers, in the branched polymers produced 
by the process of this invention the distance between branches may be 
larger, at least on average, due to the incorporation of the linear units 
C' in the final branched polymer. The incorporation of units of C into the 
final polymer structure may provide for looser branching densities (a 
lower degree of branching) and/or for the introduction of desirable 
features in the final polymers through the functionalities or 
characteristics that are inherent to the C' building blocks. 
According to the process of the present invention, both AB monomers and C 
monomers may be present together at the start of the polymerization or the 
polymerization may be started first from one or more AB monomers alone and 
an activator moiety (or external stimulus) while C is added later either 
in one addition or multiple additions, including a continuous or 
incremental addition over a defined period of time during the 
polymerization reaction. Alternately, the polymerization could be started 
using monomer C alone and a suitable initiator with a Lewis acid such as 
Et AlCl.sub.2, a base such as hydroxide, butyl lithium, or a carbanion or 
by using radiation to produce C*, and then adding the AB monomer. Yet 
another alternative is to use both AB and C monomers and add an initiator 
obtained, for example, by the reaction of compounds containing the B 
reactive group alone; i.e. not part of an AB molecule, with an activator 
moiety such as a Lewis acid, a base, or an external stimulus. 
According to one embodiment of the present invention, an A--A monomer is 
added during the polymerization, commonly in the later stages of 
polymerization, prior to its completion or quenching, to couple pre-formed 
molecules of hyperbranched polymer to increase the molecular weight of the 
final hyperbranched polymer. An A--A monomer is added in an amount and at 
a time such that precipitation of the polymer does not occur. Too much 
A--A may lead to undesirable crosslinking. If used, a suitable amount of 
A--A monomer is about 0.1 to 10 mole % of total monomer. As the amount of 
A--A increases, the reaction generally requires greater monitoring to 
terminate it prior to crosslinking or insolubilization. Suitable A--A 
monomers may be selected from any of divinyl ether, 
1,1'-bis(2-vinyloxyethoxy)-4,4'-isopropylidene diphenol, diethyleneglycol 
divinylether, butanediol divinyl ether, cylohexanedimethanol divinylether, 
hexanediol divinyl ether, cyclohexanediol divinyl ether, poly(THF) divinyl 
ether, polyethyleneglycol divinyl ether, ethylene glycol divinyl ether, 
triethyleneglycol divinyl ether, tetraethyleneglycol divinyl ether, 
divinylbenzene, bis-(4-ethenylphenyl)methane, 
bis-1,2-(4-ethenylphenyl)ethane, ethyleneglycol dimethacrylate, 
bis-1,2-(4-ethenylphenoxy) ethane, or bis-1,4-(4-ethenylphenoxy)butane. 
Particularly preferred A--A monomers are di-vinyl ether and 
bis-ethenylbenzene. 
Due to the balanced reactivities of AB, C, AB*, B*, A*, and C*, the 
composition of the polymerization mixture can be varied at will from a 
substantially AB homopolymer having only a few C monomer linear units to a 
copolymer containing almost exclusively C monomer units with only a few 
branching units resulting from the incorporation of some AB monomer. It is 
also possible to have systems in which more than one C monomer is used 
with an AB monomer or in which more than one AB monomer are used with one 
or more C monomers, provided of course that the reactivities of all the 
monomers are balanced or similar. For example, If the AB monomer is a 
vinyl ether then C will usually be a vinyl ether too and if AB is a 
styrene monomer then C will also be a styrene, although different families 
of polymers (e.g. vinyl ethers and styrenes) may be used if their 
reactivities are similar as described, for example, by Kojima et al. 
Polymer Bulletin 23,139 (1990) or in Macromolecules 24, 2658 (1991) or by 
Ohmura et al Macromolecules 27. 3714 (1994). 
The "self-constructing" polymerization will generally not provide a degree 
of branching of 1.0, because of thermodynamic, kinetic, and steric factors 
that may prevent some sites from reacting regular fashion. Therefore, a 
hyperbranched polymer with a degree of branching below to 1.0, generally 
about 0.05-0.95, preferably above about 0.2, more preferably above about 
0.3, still more preferably above about 0.5, will be obtained in all but 
ideal conditions, i.e. when there are absolutely no side reactions and 
growth follows a regular geometric pattern not affected by any steric or 
similar factor. The degree of branching of an AB hyperbranched polymer is 
defined as the mole fraction of AB monomer units located at branch points 
or chain ends. Since C functions similarly to a spacer group and its 
addition to an AB polymer leads to a looser structure with more space 
between AB units which are responsible for branching, it has no effect on 
the degree of branching. 
The hyperbranched polymers of the present invention retain their 
living-like character in that once the polymerization stops and before 
quenching is carried out the final polymer still contains many active 
sites such as A*, B* and C, that could be polymerized further using AB, C, 
or AA monomers to produce larger hyperbranched structures or star-like 
polymers with hyperbranched cores or globular block polymers with linear 
arms. Moreover, the active sites A*, B*, and C* may be quenched to produce 
many functionalized chain ends. In cationic polymerizations, suitable 
quenching agents are generally nucleophiles such as methanol, water, the 
sodium salt of diethyl malonate, amines, halides, or substituted phenyl 
lithium. In the case of anionic polymerizations, suitable quenching agents 
are generally electrophiles such as aldehydes, ketones, substituted alkyl 
or benzyl halides, alcohols, or water. As a result, the hyperbranched 
polymers have and can be designed for numerous end uses many of which are 
not possible for other polymers. 
The hyperbranched polymers are useful in the formulation of adhesives, 
carriers for drugs or biological materials, slow release formulations, 
crosslinking agents, paints, rheology modifiers, additives for coatings 
and plastics, inks, lubricants, foams, components of cosmetic 
formulations, hairspray, deodorents and the like, components of separation 
media, porosity control agents, complexing and chelating agents, carriers 
for chiral resolution agents, components of medical imaging systems, 
carriers for gene transfection, and resist or imaging materials.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
An example of the process of the present invention whereby a hyperbranched 
polymer is prepared from the AB monomer in combination with a C monomer is 
described in Reaction Scheme 1: 
##STR1## 
As shown in Reaction scheme 1, a vinyl ether AB monomer (labeled AB) and a 
Lewis acid activator are added to a different vinyl ether (labeled C) to 
afford a growing initiated moiety that can continue to grow by successive 
additions of either or both A containing moieties and C monomer units. 
Each addition to an A containing moiety results in an increase in the 
number of active growing centers contained on a single chain, therefore 
the resulting polymer becomes highly branched. Reaction Scheme 1 is a very 
general and simplified overview of the process of the invention since it 
is difficult to represent all of the different growth pathways. The AB 
monomer is shown to contain a group Sx which is a spacer group separating 
the "A" end of the monomer from the B end. This spacer group may be of 
varying length and is constituted of building blocks that are unreactive 
with A, B, C, A*, B,, C*. Therefore, the Sx group does not participate 
directly in the polymerization process but it may contribute to the 
properties of the final polymer (density, refractive index, thermal, 
mechanical, optical properties, etc.). 
The order of addition of AB and C can be varied and the initiation will 
typically occur upon addition of an activator such as ethyl aluminum 
sesquichloride as shown. As described previously, it is possible to 
achieve a similar objective by adding a classical living-type 
polymerization initiator such as 1-acetoxyethylbenzene, or 
4-acetoxypentane or 1-phenoxy-2-(1-acetoxyethyloxy)ethane or 
(1-acetoxyethyloxy)ethane that contains the 1-acetoxyethyl group found in 
B plus an activator to the mixture of monomers AB and C (or to C, then 
adding AB, and the like). Other initiating systems such as those described 
by Aoshima et al., J. Polymer Science, A, Polymer chemistry 32, 1729 
(1994) and references therein are also suitable. 
As is well known in the art, the cationic polymerization of vinyl ethers 
requires that special conditions be maintained to ensure that undesirable 
side-reactions such as crosslinking, chain transfer or termination are 
avoided. The use of such standard precautions as described for example in 
the review by M. Sawamoto, Prog. Polym. Sci., 1991, 16, 111-172 is 
preferred. For example, polymerization is generally carried out in the 
absence of water and in the presence of slightly basic agents such as 
ethers or esters that help stabilize the "living" chain ends (propagating 
groups). Conditions must also be maintained to prevent elimination 
reactions. Suitable conditions are well known in the art and include the 
absence of water, selection and strength of the Lewis acid and of the 
complex formed between the Lewis acid and the carbocationic center, the 
addition of a "basic" or "nucleophilic" additive such as dioxane, 
tetrahydrofuran, ethylacetate, or 2,6-di-t-butyl pyridine to stabilize the 
carbocationic propagating center, and the like. For an anionic process, 
suitable conditions include the use of a dry solvent such as 
tetrahydrofuran or cyclohexane and the absence of water or electrophilic 
impurities such as aldehydes, ketones, benzylic or aliphatic halides. The 
use of additives such as glymes or cyclic ethers including tetrahydrofuran 
or dioxane, or tetramethyl ethylenediamine (TMEDA), or hexamethyl 
phosphoramide (HMPA) or crown ethers and cryptants that help stabilize the 
propagating center is also well known in the art. (See, for example, P. 
Rempp and E. Merrill in "Polymer Synthesis" 2nd Edition, chapter 5, 
(Huthig & Wepf). 
To simplify the representation in Reaction Scheme 1, it is assumed that all 
AB molecules are transformed into AB, molecules at the start of the 
process. This is not a requirement because both A* and B* can react with 
any molecule containing a reactive A and/or a reactive C group. 
Once the polymerization is complete, the remaining activated A*, B*, and C* 
sites can be terminated by addition of a suitable reagent. In the case of 
the cationic polymerization shown in Reaction Scheme 1, this reagent could 
be a nucleophile like methanol, water, amine, halide ion, or the sodium 
salt of diethyl malonate, or a substituted phenyl lithium. In the case of 
anionic polymerizations, suitable reagents are generally electrophiles 
such as aldehydes, ketones, substituted alkyl or benzyl halides, alcohols, 
or water. The same would also apply to a group transfer polymerization 
that involve electrophiles as terminating agents. For example, styrene AB 
and C monomers polymerized cationically would be terminated by reaction 
with nucleophilic reagents, while styrene monomers polymerized anionically 
would be terminated by electrophilic reagents. Vinyl ether AB and C 
monomers would be polymerized cationically and therefore they would be 
terminated with nucleophilic reagents. Acrylic monomers AB and C 
polymerized by group transfer polymerization would be terminated using 
electrophilic reagents. 
In Reaction Scheme 1, the active chain-ends or propagating sites (A* and B* 
groups) are shown by a "+" sign indicating their cationic nature. The 
counterions represented by an "X" and a "-" sign may be any suitable 
counterion such as Et.sub.1.5 AlCl.sub.1.5 (OAc), C.sub.2 H.sub.5 
AlCl.sub.2 OAc, I.sub.2 Ac or I.sub.3.sup.-. 
Reaction Scheme 2 shows the structure of a typical growing chain that is 
applicable in the case where the polymerization is initiated by the 
preferred process of the addition of an activator; e.g., Lewis acid, base 
or external stimulus such as heat or light, to monomers AB and C. Because 
a vinyl ether is depicted the activator is a Lewis acid. 
##STR2## 
As shown, a characteristic of these chains is the presence of one reactive 
vinyl group per growing chain (top left of Reaction Scheme 2, labeled as 
"center group") as well as many cationic centers (shown by a + sign). 
Reaction Scheme 3 below is also oversimplified as growth is shown with an 
alternation of monomer units AB and C in the main-chain of the copolymer. 
In all but ideal situations, the chain would grow in more random fashion; 
growth being affected by the nature of the two monomers, their relative 
reactivities and concentrations, etc. 
In the special case of initiation using a classical living-like 
polymerization initiator; e.g. B-like initiator plus an activator, the 
growing chains may or may not look like the structure shown in Reaction 
Scheme 2, because it is possible to have "center groups" derived from the 
initiator molecule itself and therefore without a vinyl group. 
Reaction Scheme 3 shows a final polymer corresponding to the growing chains 
of Reaction Scheme 2 after termination of growth by addition of methanol 
as described in greater detail in the Examples. Other reagents such as 
water, the sodium salt of diethyl malonate, substituted phenyl lithium, or 
other nucleophiles may also be used to effect termination. 
##STR3## 
In this fashion, a hyperbranched polymer containing numerous reactive 
groups at its chain ends is obtained. 
The specific shape (globular, globular-linear blocks, star, loose highly 
branched chains, etc.) of the copolymers obtained in accordance with this 
invention is primarily controlled by the following six factors: 
(1) ratio of AB to C monomers; 
(2) relative reactivities of A and C towards activated species A*, B* and 
C*; 
(3) thermodynamic and steric factors; 
(4) method of addition of AB or C monomers; 
(5) eventual addition of an additional initiator molecule (such as a B 
moieties alone; not coupled with A); 
(6) combinations involving more than one AB and C monomer such as two 
different AB monomers and one C monomer, or two different AB monomers and 
two C monomers, etc. 
In addition to the versatility of functionalities allowed by the AB 
structures themselves, the use of a C monomer allows the introduction of 
additional functional groups throughout the highly functionalized polymer. 
Therefore, the nature and reactivity of the main chain of the highly 
branched macromolecule can be controlled through the choice of C. For 
example, C may carry a pendant group that does not participate in the 
polymerization but is available for subsequent reactions involving the 
finished highly branched polymer; e.g. pendant acrylic group, masked 
amine, masked alcohol or protected carboxylic group. It must be emphasized 
that this versatility is in addition to that provided through the control 
of chain ends and other groups included in the A-B units and the choice of 
the termination reaction. The nature and amount of C used in the 
copolymerization can affect the final properties of the hyperbranched 
copolymers. For example, C may change the physical and mechanical 
properties such as viscosity or modulus of the final hyperbranched 
copolymer. 
AB molecules useful in the present invention are best represented by the 
formula A-(Sx).sub.p -B in which A and B are as defined above, Sx is a 
spacer group separating A from B and p is an integer of 0, 1 or 2. In the 
specific compositions shown below a bond is shown on A and B to show the 
point of attachment of either to the other or to Sx. The term AB monomer 
as used herein means A-(S).sub.p -B. In this formula when p is 2, there 
may two of the same Sx groups or the two Sx groups may be different. 
Moreover, according to this definition, Sx need not be present in any of 
the monomers. A spacer group S changes the distance between branch points 
and may be used to contribute to the final polymer properties such as 
resistance to oil, elongation, rigidity, shape, thermal or optical 
properties or the like or it may be used to introduce reactive pendant 
groups such as pendant acrylic group, masked amine, masked alcohol or 
protected carboxylic groups. Any such pendant group must be inert to the 
polymerization reaction used to prepare the hyperbranched polymer. Only 
certain A, B and S groups are compatible with each other. Only certain C 
monomers may be used with certain AB monomers. Thus, they are described in 
compatible groups hereinafter. 
While any A, B, C and Sx groups may be used, they must be compatible with 
each other. The compatibility of A, B, C and Sx groups is related to the 
reactivity of A, B, C, Sx, A, B, and C*. Compatible groups are those for 
which the reactivity of A*, B* and C* with an A group will be 
substantially similar such that the polymerization may proceed through any 
of A*, B* or C* alone. The compatibility of the Sx group with A B and C 
relate to its inability to react chemically with A, B, C, A* or B* or C* 
moieties for example to cause the formation of a new active propagating 
center through processes such as addition, chain transfer, or elimination 
reaction. Non-compatible groups may lead to side reactions such as chain 
transfer, inhibition, elimination or termination that may prevent growth 
of the hyperbranched polymer. 
Since certain A, B, and Sx groups may not be compatible with each other, 
preferred such groups are specified below by compatible groups. 
The first AB monomer grouping is represented by the formula A.sup.1 
(S.sup.1).sub.p B.sup.1 wherein A.sup.1 is selected from any of 
##STR4## 
wherein R.sup.1 is selected from any of H or C.sub.1 -C.sub.4 alkyl, 
preferably H; and R.sup.2 is selected from any of H and C.sub.1 -C.sub.4 
alkyl, preferably H. 
A suitable companion B.sup.1 group for the A.sup.1 groups is represented by 
the general formula: 
##STR5## 
R.sup.3 is selected from any of C.sub.1 -C.sub.4 alkyl, dilphenyl, aryl 
such as phenyl or naphthyl, optionally substituted with one or more 
substituent such as halo, cyano, C.sub.1 -C.sub.4 alkyl, and C.sub.1 
-C.sub.4 alkoxy. Preferably, R.sup.3 is C.sub.1 -C.sub.4 alkyl, most 
preferably methyl. R.sup.4 is selected from any of H or C.sub.1 -C.sub.4 
alkyl. More preferably R.sup.4 is H. X.sup.1 is 0. "t" is 0 or 1. X.sup.2 
is OR.sup.5, OCOR.sup.5, or halo, preferably chloro. R.sup.5 is C.sub.1 
-C.sub.4 alkyl, haloalkyl, aryl, or aralkyl, more preferably methyl. 
A suitable S.sub.x.sup.1 group which may be used with the above described 
companion A.sup.1 and B.sup.1 groups may be selected from any of C.sub.2 
-C.sub.12 alkylene, substituted C.sub.2 -C.sub.12 alkylene wherein the 
substituents are selected from C.sub.1 -C.sub.4 alkyl or aralkyl wherein 
the alkyl is C.sub.1 -C.sub.4 ; 
##STR6## 
wherein m and n are the same or different and are each integers from 0 to 
about 18, Ar.sup.1 and Ar.sup.2 are the same or different and are aryl 
selected from phenyl, naphthyl, biphenyl, optionally substituted with one 
or more substituents selected from C.sub.1 -C.sub.4 alkyl, C.sub.1 
-C.sub.4 alkoxy, halo, or acetoxy; 
##STR7## 
wherein y=0 or 1, and X.sup.3 is selected from any of O, S, SO.sub.2, 
CH.sub.2 or CO; 
##STR8## 
wherein R.sup.5 is C.sub.1 -.sub.4 alkyl or aryl; 
##STR9## 
polystyrene, polyisobutylene, polyester, polyether, polyolefin, 
polyetherketone, polycarbonate, polysulfone; or 
##STR10## 
wherein W is 
##STR11## 
More preferably, S.sub.x.sup.1 selected from any of 
##STR12## 
Suitable C monomers which may be reacted with the preceding A.sup.1 
(S.sub.x.sup.1).sub.p B.sup.1 monomer is C.sup.1, represented by the 
general formula: 
##STR13## 
R.sup.11 is selected from any of H or C.sub.1 -C.sub.6 alkyl, more 
preferably methyl or H and most preferably H; R.sup.12 is selected from 
any of H or C.sub.1 -C.sub.6 alkyl, more preferably methyl or H and most 
preferably H; R.sup.13 is selected from any of C.sub.1 -C.sub.18 alkyl, 
C.sub.1 -C.sub.18 haloalkyl, aralkyl, 
##STR14## 
--Si--(R.sup.16).sub.3, and --CH.sub.2 CH.sub.2 OSi(R.sup.16).sub.3. 
R.sup.14 is C.sub.1 -C.sub.18 alkyl, C.sub.1 -C.sub.18 haloalkyl, aralkyl, 
or 
##STR15## 
wherein R.sup.17 is OCH.sub.3 or CN. R.sup.15 is C.sub.1 -C.sub.18 alkyl, 
C.sub.1 -C.sub.18, haloalkyl, aralkyl, 
##STR16## 
wherein R.sup.18 is H, phenyl or --CH.dbd.CH--CH.sub.3. R.sup.16 is 
C.sub.1 -C.sub.18 alkyl or aryl. 
Alternatively, the A, B and Sx groups in an AB monomer may be represented 
by the formula A.sup.2 (S.sub.X.sup.1)B.sup.2 wherein A.sup.2 is selected 
from 
##STR17## 
wherein R.sup.6 is H or C.sub.1 -C.sub.4 alkyl, preferably H; Ar.sup.3 is 
aryl or N-alkyl-3-carbazoyl wherein the alkyl is C.sub.1 -C.sub.4, 
preferably phenyl; (X.sup.4).sub.y is O or CH.sub.2, preferably X.sup.4 is 
O attached to a phenyl Ar.sup.3 at the para position; and y is 0 or 1. 
A suitable Compatible B.sup.2 group is: 
##STR18## 
R.sup.7 is selected from any of H, CH.sub.3, C.sub.1 -C.sub.8 alkyl or 
aryl, preferably H. R.sup.8 is H or C.sub.1 -C.sub.8 alkyl, preferably 
methyl. X.sup.5 is halo, OR.sup.9, or OCH.sub.2 OCO-R.sup.9 wherein 
R.sup.9 is selected from any of C.sub.1 -C.sub.8 alkyl, C.sub.1 -C.sub.8 
haloalkyl or aryl; preferably X.sup.5 is chloro. 
B.sup.2 may also be selected from 
##STR19## 
R.sup.10 is selected from any of C.sub.1 -C.sub.8 alkyl or aryl, 
preferably methyl. X.sup.6 is halo such as chloro, bromo, iodo, etc., 
preferably chloro. 
A suitable C monomer which may be used with the immediately preceding 
A.sup.2 (S.sub.X.sup.1)B.sup.2 monomer is C.sup.1 as previously defined 
herein or and most preferably C.sup.2 selected from any of 
##STR20## 
wherein R.sup.19 is selected from any of C.sub.1 -C.sub.8 alkyl, aralkyl 
or --COO-alkyl (C.sub.1 -C.sub.8 ); 
##STR21## 
wherein R.sup.20 is selected from any of H or C.sub.1 -C.sub.12 alkyl; or 
##STR22## 
Alternatively, the A, B and S.sub.x groups in an AB monomer may be 
represented by the formula A.sup.3 (S.sub.X.sup.2)B.sup.3 wherein A.sup.3 
is selected from any of 
##STR23## 
A suitable B.sup.3 group is 
##STR24## 
wherein S.sub.x.sup.2 is C.sub.1 -C.sub.8 alkyl, aryl, substituted aryl, 
aralkyl substituted aralkyl or --(CH.sub.2 --CH.sub.2 --O--).sub.r, 
wherein r is 1-18 and wherein the substituents are selected from any of F, 
OCH.sub.3, or C.sub.1 -C.sub.12 alkyl. 
The C monomer which may be used with the preceding A.sup.3 
(S.sub.X.sup.2)B.sup.3 monomer, C.sup.3, may be selected from any of 
##STR25## 
wherein R.sup.21 is H or CH.sub.3 and R.sup.22 is C.sub.1 -C.sub.18 alkyl, 
aryl or aralkyl; 
##STR26## 
wherein R.sup.23 is C.sub.1 -C.sub.18 alkyl. 
Alternatively, the A, B, and Sx groups in an AB monomer may be such that 
the AB monomer is selected from any of 
##STR27## 
wherein X.sup.7 is halo, preferably chloro or bromo, and R.sup.24 is H or 
C.sub.1 -C.sub.6 alkyl, preferably CH.sub.3. 
The C monomer used with the preceding AB monomers is a styrene of the 
formula: 
##STR28## 
wherein R.sup.25 is in the 3 or 4 position and is selected from H, alkyl 
C.sub.1 -C.sub.6, --O-alkyl (C.sub.1 -C.sub.6), --OCO-alkyl (C.sub.1 
-C.sub.6), and --O--Si-trialkyl (C.sub.1 C.sub.6); preferably H or alkyl 
C.sub.1 -C.sub.4 ; more preferably H or CH.sub.3. 
Particularly suitable AB monomers include: 1-(2-vinyloxyethyl- 
oxy)-1'-[2-(1-acetoxyethoxy)-ethyloxy]bisphenol; 
1-vinyloxymethyl-4-(1-acetoxy)ethyloxymethylcyclohexane; 
1-(2-vinyloxyethyl)-4-[1-acetoxyethyloxy)ethyl]terephthalate; 
2-(2-vinyloxyethyl)-2-[(1-acetoxyethyloxy)ethyl]diethyl malonate; 
1-(2-vinyloxyethyl)-3-[(1-acetoxyethyloxy)ethyl]-5-(2-methacryloxyethyl)-1 
,3,5-benzene tricarboxylate; 
1-[(4-ethenyl)-phenoxymethyl]-4-[4-(1-chloroethyl)phenoxymethyl]benzene; 
4(2-(1-chloroethyloxy))ethyloxystyrene; 4-(1-bromoethyl)styrene; 
4-(1-chloroethyl)styrene; chloromethylstyrene; 3-(1-bromoethyl)styrene; 
and 3-(1-chloroethyl)styrene. 
Particularly suitable C monomers include 2-methoxyethyl vinyl ether, 
2-(trimethylsilyloxy)ethyl vinyl ether, isobutyl vinyl ether, 
2-methoxyethyl vinyl ether, 2-butoxyethyl vinyl ether, ethyl vinyl ether, 
methyl vinyl ether, butyl vinyl ether, cyclohexylmethyl vinyl ether, 
[4-(methoxymethyl)cyclohexyl]methyl vinyl ether, 
2-(trimethylsilyloxy)ethyl vinyl ether, 2-(t-butyldimethylsilyloxy)ethyl 
vinyl ether, t-amyl vinyl ether, triethyleneglycol methyl vinyl ether, 
2-ethylhexyl vinyl ether, cylohexylvlnyl ether, 4-(trimethylsilyloxy)butyl 
vinyl ether, [4-(trimethylsilyloxymethyl)cyclohexyl]methyl vinyl ether, 
4-methoxystyrene, 4-methylstyrene, 4-acetoxystyrene, 
4-t-butyldimethylsilyloxystyrene, 4-trimethylsilyloxystyrene, 
4-(2-methoxyethoxy)styrene, methylmethacrylate, ethyl methacrylate, butyl 
methacrylate, phenyl methacrylate, methyl acrylate, ethyl acrylate, butyl 
acryiate, phenyl acrylate, N,N-dimethyl methacrylamide, 
N,N-dimethylacrylamide, N-vinylcarbazole. 
As used herein, unless otherwise noted alkyl and alkoxy, whether used alone 
or as part of a substituent group, include straight and branched chains. 
For example, alkyl radicals include methyl, ethyl, propyl, isopropyl, 
n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, 3-(2-methyl)butyl, 
2-pentyl, 2-methylbutyl, neopentyl, n-hexyl, 2-hexyl and 2-methylpentyl. 
Alkoxy radicals are oxygen ethers formed from the previously described 
straight or branched chain alkyl groups. 
The term "aryl" as used herein alone or in combination with other terms 
indicates aromatic hydrocarbon groups such as phenyl or naphthyl. The term 
"aralkyl" means an alkyl group substituted with an aryl group. 
While certain currently preferred substituents are identified above, these 
are not intended in any manner to limit the substituents which may be 
present on the various AB and C compounds, provided that they do not 
interfere in the primary polymerization reactions. 
EXAMPLES 
In the Examples, the following abbreviations have the meanings recited: 
DMSO=Dimethyl sulfoxide; THF=Tetrahydrofuran; CEVE=2-Chloroethyl vinyl 
ether; TLC=Thin layer chromatography; Et=ethyl and SEC=Size-exclusion 
chromatography; Bu=butyl; Ac=acetyl. 
Example I 
Preparation of Vinyl Ether-Type A-B Molecule (1) 
1-(2-vinyloxy-ethyloxy)-1'-[2-(1-acetoxyethoxy)-ethyloxy]-4,4'-isopropylid 
ene diphenol 
##STR29## 
A mixture of bisphenol A (23 g), powdered NaOH (12 g), and DMSO (45 ml) 
were heated at 70.degree.-75.degree. C. with stirring under nitrogen for 
1.5 hours. To the mixture, CEVE (39 g) was added slowly over 2 hours. An 
additional 20 ml of DMSO was added to this viscous mixture. Then the 
solution was heated for another 5 hours at 70.degree.-75.degree. C., and 
was allowed to stand overnight at room temperature. The reaction mixture 
was washed with water, and the isolated crude products purified by 
crystallizing twice from ethanol. The aromatic bisvinyl ether (2) was 
obtained as a white-pale yellow solid in 75% yield. 
The preparation of acetic acid-adduct of the bisvinyl ether of bisphenol 
was carried out as follows. To the solution of bisvinyl ether 2 (7.4 g) in 
toluene (15 ml), was added a slight excess of glacial acetic acid (1.4 g). 
The mixture was heated at 70.degree. C. under nitrogen for 8 hours. After 
cooling the mixture was evaporated to remove toluene and unreacted acetic 
acid. The yellowish oil was obtained almost quantitatively (&gt;95%). TLC 
showed that the crude products contained three major materials: unreacted 
2, mono-adduct of acetic acid to 2 (1), and di-adduct of acetic acid. 
The mono-adduct of acetic acid to 2 (vinyl ether 1), an A-B type molecule, 
was separated from the mixture by flash chromatography eluting with 
hexane/diethyl ether (60/40); the Rf values of three fractions are 0.56, 
0.31, 0.14, respectively. The eluent was them removed on a rotary 
evaporator and vacuum dried for 1 hour. A colorless transparent oil was 
obtained (43% yield based on 2). 
Cationic copolymerization of Isobutylvinyl ether (IBVE) with 1 as an A-B 
Molecule 
The purified 1 and isobutyl vinyl ether were dissolved in the mixture of 
dry ethyl acetate and hexane, and, the solution was allowed to stand 
overnight over granular CaH.sub.2, to remove trace amounts of water. The 
transparent supernatant fraction was then transferred to the reaction 
vessel and used to prepare the monomer solution. Polymerization was 
carried out under dry nitrogen in a baked glass vessel equipped with a 
three-way stopcock. The reaction was initiated by addition of E.sub.1.5 
AlCl.sub.1.5 in toluene used as an activator to the solution containing 
IBVE, 1 and ethyl acetate in hexane at 0.degree. C. ([IBVE].sub.0 =0.76 
mol/l, [1].sub.0 =[Et.sub.1.5 AlCl.sub.1.5 ].sub.0 =0.15 mol/l, [ethyl 
acetate].sub.0 =2.0 mol/l; total scale of the reaction: 5 ml). Ethyl 
acetate was used as an added base to stabilize the propagating 
carbocations by its nucleophilic interaction and prevent the occurrence of 
various side reactions such as crosslinking, chain transfer reaction etc. 
After 30 min, the reaction was quenched by 2 ml of 0.3 wt % ammonia in 
methanol. The quenched reaction mixture was diluted with hexane and then 
washed with dilute hydrochloric acid (0.6 mol/l) and water to remove the 
initiator residues. After neutralization, the polymer product was 
recovered by evaporation of the solvents under reduced pressure, and 
vacuum dried overnight. The colorless polymer is isolated quantitatively 
as a viscous liquid. The polymer is completely soluble in hexane, toluene, 
THF, ethyl acetate, chloroform. The molecular weight measured by SEC with 
polystyrene standard (THF, 40.degree. C.) was MW=2.times.10.sup.4. The 
molecular weight distribution curve showed a clear shoulder extending to 
5.times.10.sup.5. The structure of the polymer is confirmed by NMR and IR. 
Example II 
Preparation of Hyperbranched Poly(1) with Higher Molecular Weight 
The polymerization was carried out as above with addition of small amount 
of 2 (A--A type molecule, 0.01 mol/l) after 30 min followed by quenching. 
The work up process was similar to that in Example I. The polymer was 
obtained in 88% yield. The polymer is completely soluble in THF, ethyl 
acetate, chloroform. SEC measurement with the resulting polymer shows that 
Mw exceeds 100,000 as measured with polystyrene standards. 
Example III 
Preparation of Vinyl Ether-Type A-B Molecule (3) 
4-vinyloxymethyl-4-(1-acetoxy]ethyloxymethylcyclohexane 
##STR30## 
Vinyl ether-type A-B molecule 3 was prepared by the following two steps 
that include the synthesis of bisvinyl ether 4 by vinyl 
transetherification and the reaction with acetic acid. To a solution of 
distilled ethyl vinyl ether (29 ml, 0.3 mol), 1,4-cyclohexyl dimethanol 
(11 g, 0.075 mol), and 1,4-dioxane (15 ml) were added mercury(II) acetate 
(0.75 g, 0.0024 mol) as a catalyst and molecular sieves 4A (20 g) as an 
adsorbent of ethanol. The reaction was carried out at room temperature for 
5 hours with occasional shaking. The reaction was then stopped by adding 2 
g of anhydrous potassium carbonate. The reaction mixture was washed with 
water, dried over Na.sub.2 SO.sub.4, and fractionated by flash 
chromatography eluting with hexane/diethyl ether (50/50)(yield 
.about.20%). 
The reaction of 4 (5.2 g) with acetic acid (1.9 g) was carried out at 
70.degree. C. under nitrogen. After 4 hours, the reaction mixture was 
allowed to cool, and evaporated to remove unreacted acetic acid. A 
colorless oil was obtained. The mono-adduct of acetic acid to 4, an A-B 
type molecule (3), was separated from the mixture by flash chromatography 
eluting with hexane/diethyl ether (80/20). The eluent was removed on a 
rotary evaporator and vacuum dried for 1 hour. The product was obtained as 
a colorless transparent oil (40% yield based on 4). 
Cationic Copolymerization of IBVE with 3 as an A-B Type Molecule 
Purified 3 and IBVE were dissolved in the mixture of dry ethyl acetate and 
hexane, and the solution was allowed to stand overnight over granular 
caH.sub.2 to remove trace amounts of water. The transparent supernatant 
fraction was transferred to the reaction vessel and used to prepare the 
monomer solution. The polymerization process was similar to that of 
compound 1 of Example I except for the use of EtAlCl.sub.2 as the 
activator instead of Et.sub.1.5 AlCl.sub.1.5. The reaction was initiated 
by addition of EtAlCl.sub.2 in hexane to the solution containing IBVE, 3 
and ethyl acetate in hexane at 0.degree. C. ([IBVE].sub.0 =0.76 mol/l, 
[3].sub.0 =0.15 mol/l, [EtAlCl.sub.2 ].sub.0 =0.16 mol/l, [ethyl 
acetate].sub.0 =4.0 mol/l; total scale of the reaction: 5 ml). Ethyl 
acetate was used as an added base to stabilize the propagating 
carbocations by its nucleophilic interaction and prevent the occurrence of 
various side reactions such as crosslinking, chain transfer, etc. The 
polymerization reaction progressed homogeneously. After 30 min, the 
reaction was quenched by 2 ml of 0.3 wt % ammonia in methanol. Work up was 
as described for compound 1 (see Example I). The polymer was obtained in 
89% yield as a viscous liquid. The polymer was completely soluble in 
hexane, toluene, THF, ethyl acetate, and chloroform. The molecular weight 
measured by SEC with polystyrene standard (THF, 40.degree. C.) was 
MW=10.sup.4. The molecular weight distribution curve showed a shoulder 
extending to 10.sup.5. The structure of the polymer is confirmed by NMR 
and IR. 
Example IV 
Preparation of Highly Branched Copolymer of IBVE and 1 with Different 
Lengths of Branches 
Purified 1 was dissolved in the mixture of dry ethyl acetate and hexane, 
and the solution was allowed to stand overnight over granular CaH.sub.2 to 
remove trace amounts of water. The copolymerization with IBVE and 
following work up processes were similar to those for compound 1 (see 
Example I) except for the different ratios of [IBVE].sub.0 /[I].sub.0 that 
were used varying from 1:1 to 500:1. In all cases evaporation of the 
copolymerized mixture after quenching and work-up gave yields of copolymer 
exceeding 85%. Each of the copolymers was found to be completely soluble 
in hexane, toluene, THF, ethyl acetate, and chloroform. The polymer was 
characterized as described in Examples I and III. 
Example V 
Preparation of Highly Branched Copolymer of 2-Methoxyethyl Vinyl Ether and 
1 
Purified 1 was dissolved in the mixture of dry ethyl acetate and toluene, 
and the solution was allowed to stand overnight over granular CaH.sub.2 to 
remove trace amounts of water. The copolymerization and following work up 
processes were similar to those for compound 1 and IBVE (see Example I) 
except for the difference of the added monomer: 2-methoxyethyl vinyl ether 
instead of IBVE ([2-methoxyethyl vinyl ether].sub.0 =0.76 mol/l) and 
solvent, toluene. The polymer was obtained in 92% yield. The polymer is 
completely soluble in toluene, THF, ethyl acetate, and chloroform. The 
polymer was characterized as described in Examples I and III. Furthermore, 
the polymer solution in water exhibits the characteristic of 
thermally-induced phase separation. 
Example VI 
Preparation of Highly Branched Amphiphilic Block Copolymer 
Purified 1 was dissolved in the mixture of dry ethyl acetate and hexane, 
and the solution was allowed to stand overnight over granular CaH.sub.2 to 
remove trace amounts of water. The copolymerization of 1 with IBVE was 
carried out as described in example 1 until 95-100% conversion of the IBVE 
monomer at which point a fresh feed of 2-(trimethylsilyloxy)ethyl vinyl 
ether was added ([2-(trimethylsilyloxy)ethyl vinyl ether].sub.0 =0.5 
mol/l). The polymer was obtained in 95% yield. The quenched reaction 
mixture was diluted with ethyl acetate and then washed with dilute 
hydrochloric acid (0.6 mol/l) and water to remove the initiator residues. 
During this washing procedure or during the further treatment with a 
catalytic amount of methanolic HCl for less than 5 min at room 
temperature, quantitative desilylation of the polymer occurred, to give a 
block containing alcohol units. After neutralization and washing the 
polymer product was recovered by evaporation of the solvents under reduced 
pressure, and vacuum dried overnight. The colorless polymer is isolated 
essentially quantitatively as a viscous liquid. The polymer is soluble in 
THF, ethyl acetate, and chloroform. The highly branched polymer containing 
a hydrophobic poly(IBVE) unit and a hydrophilic poly(2-hydroxyethyl vinyl 
ether) unit was characterized as described in Examples I and III. 
Example VII 
Terpolymerization of IBVE with Two Different A-B Type Molecules 
The terpolymerization of IBVE with two different A-B type molecules of 
comparable reactivities was carried out similarly to Examples I and III. 
Purified 1 and 3 were dissolved in a mixture of dry ethyl acetate and 
hexane, and the solution was allowed to stand overnight over granular 
CaH.sub.2 to remove trace amounts of water. The transparent supernatant 
fraction was transferred to the reaction vessel and used to prepare the 
monomer solution. The polymerization process was similar to those for 
compounds 1 or 3 (see Example I or III). The reaction was initiated by 
addition of EtAlCl.sub.2 in hexane to the solution containing IBVE, 1 and 
3, and ethyl acetate, in hexane at 0.degree. C. ([IBVE].sub.0 =0.76 mol/l, 
[EtAlCl.sub.2 ].sub.0 =[1].sub.0 +[3].sub.0 =0.15 mol/l, [ethyl 
acetate[.sub.0 =2.0 mol/l; total scale of the reaction: 5 ml). Ethyl 
acetate was used as an added base to stabilize the propagating 
carbocations by its nucleophilic interaction and prevent the occurrence of 
various side reactions such as crosslinking, chain transfer, etc. After 30 
min, the reaction was quenched by 2 ml of 0.3 wt % ammonia in methanol. 
Work up was as described for compound 1 (see Example I). The polymer was 
obtained in 96% yield as a viscous liquid. The polymer was completely 
soluble in hexane, toluene, THF, ethyl acetate, and chloroform. The 
polymer was characterized as described in Examples I and III. 
Example VIII 
Preparation of Tree-Like Polymers 
Preparation of tree-like polymers was carried out similarly to Example I. 
On the first step, the living polymer of IBVE with a narrow molecular 
weight distribution (Mn=1.6.times.10.sup.4, Mw/Mn=1.06) was obtained by 
the living cationic polymerization with (CH.sub.3 CHO) isoC.sub.4 
H.sub.9)OCOCH.sub.3 (B)/EtAlCl.sub.2 in the presence of ethyl acetate at 
0.degree. C. ([IBVE].sub.0 =0.76 mol/l, [5].sub.0 =4 mmol/l, [EtAlCl.sub.2 
].sub.0 =20 mmol/l; conversion: 75%; total scale of the reaction: 5 ml). 
To the reaction mixture, compound 1 and extra IBVE were added ([1].sub.0 
=16 mmol/l, [IBVE].sub.0 =1.0 mol/l), followed by quenching and work up as 
described in Example I. The resulting tree-like polymer with a linear 
block attached to a globular highly branched block has Mn=5.times.10.sup.4 
which is close to the calculated value. The polymer was completely soluble 
in hexane, toluene, THF, ethyl acetate, and chloroform. The polymer was 
characterized as described in Examples I and III. 
As starting polymers, the highly branched polymer obtained in the Example I 
or III are also available, instead of the living poly(IBVE) to give more 
highly branched polymers with higher molecular weight (MW&gt;10.sup.5). A 
second portion of IBVE may also be added to the tree-like polymer to 
extend and increase the branches. 
Example IX 
Chemical Modification of Terminal Groups in the Polymer 
As shown in Reaction Scheme 3, this type of highly branched polymer has a 
large number of useful terminal groups. As one example, chemical 
modification of the terminal groups was carried out by using a polymer 
with acetal terminal groups in Reaction Scheme 3 obtained under the 
conditions of Example I. The polymer was dissolved in dioxane, and then 
allowed to react with 1N HCl aqueous solution at room temperature, 
followed by neutralization. The quantitative conversion to aldehyde is 
confirmed by NMR. 
Example X 
Copolymerization of 4-(1-chloroethyl) styrene with 4-methlstyrene 
A freshly dried glass apparatus was used for this polymerization under 
nitrogen atmosphere. A solution of 4-(1-chloroethyl)styrene (1.0 g, 6 
mmoles) and 4-methylstyrene ((0.72 g, 6 mmoles) in dichloromethane (6 ml) 
was cooled to -15.degree. C. then pre-cooled SnCl.sub.4 (3 mmoles) 
dissolved in dichloromethane was added under nitrogen. A color change was 
observed upon mixing and the color increased as the temperature was 
allowed to rise to 0.degree. C. After 8 hours of reaction with occasional 
stirring under inert atmosphere, the polymerization was quenched by 
addition of pre-chilled methanol (10 ml) containing a trace of ammonia. 
The color was discharged and the mixture diluted with dichloromethane then 
washed with 2% aqueous HCl and distilled water (5 times). The organic 
layer was concentrated and the copolymer (83% yield) isolated by 
precipitation from THF into methanol. After reprecipitation into hexanes 
its peak molecular weight measured by standard GPC with polystyrene 
standards was 70,000. The structure of the polymer was further confirmed 
by NMR in CDCl.sub.3 and by infrared spectroscopic analysis. 
Example XI 
Copolymerization of 4-(1-chloroethyl) styrene with vinyltoluene 
The copolymerization of the mixture of monomers (10 mmoles of each in a 
total of 10 ml dichloromethane) was accomplished as described in Example X 
except using inverse addition of the prechilled monomer solution to a 
solution containing SnCl.sub.4 (5 mmoles) and tetrabutylammonium chloride 
(2.0 mmole) in dichloromethane cooled to -30.degree. C. Once the addition 
was complete, the mixture was brought slowly from -30.degree. C. to 
0.degree. C. with occasional mixing until the polymerization was quenched 
after 12 hours as described above. The highly branched copolymer was 
processed and characterized as described above in Example X.