Functionalized polyesters copolymers

To design amphiphilic and/or reactive copolymers containing aliphatic polyesters, one of the most promising approaches is copolymerization with functional monomers having protected reactive side-chain groups. Some kinds of monomers having reactive (hydrophilic) side-chain groups have been reported (Fig. 3). Recently, the synthesis of various types of functional polyesters has been reviewed [15-19],... 

Last but not least, some of us have recently synthesized polyimide-aliphatic polyester triblock and graft copolymers in collaboration with Hedrick and his coworkers [ 97,98]. Well-defined aminophenyl or diaminophenyl end-functional polyester oligomers have been synthesized on purpose and used as end-cappers or macromonomers leading to the aforementioned triblock or graft copolymers, respectively. The polyimide-polyester copolymers so obtained proved to be highly efficient promoters of polyimide nanofoams (for more details see Sect. 4.2). 

Studies have been made of PEST/PO/styrene copolymer blend compatibilization in which a copolymer may be formed between polyester alcohol end-groups and pendent anhydride functionality on a styrene copolymer (Table 5.27). Because the alcohol-anhydride reaction is reversible (with the equilibrium lying on the side of unreacted anhydride), only a relatively small amount of copolymer may be formed. In consequence, the dispersed phase polymer may not be well stabilized against coalescence upon further thermal treatment [Sun et al., 1996]. Alternatively, at least some copolymer may be formed by a degradative mechanism through transesterification between PEST main-chain linkages and a low concentration of pendent acid groups in anhydride-functionalized styrene copolymer (see Section 5.7.12.5). 

Chem. Descrip. Polyester-modified, hydrory-functional acrylic copolymer emulsion (47%) in water CAS 25133-97-5... 

PEST/PPE blends have been compatibilized through graft copolymer formation between polyester and a PPE-miscible functionalized styrene copolymer (Table 5.39). In this instance, the reaction is between polyester carboxylic acid... 

Insights into the chemical properties of polyesters have also been obtained using afm imaging as a tool. The dififusion/deposition of oligomers to the surface of PET copolyesters was demonstrated by imaging hard nodules on the polyester surfaces as a function of copolymer composition. The frequency of these hard nodules observed by afm correlated with the levels of oligomer that could be solvent-extracted from the copolymers (96). 

PMMA Polyester elastomers PMMA (hydroxyl functional) star copolymer incorporated in crosslinked polyester elastomers giving excellent balance of hardness/flexibUity 824... 

Another approach to increase the molecular weight of polyesters obtained in direct polycondensation is to use chain-extenders, for example through the reaction of oc,(jo-functionalized polyesters with diisocyanates or oxazo-lines " Using hexamethylene diisocyanate as a chain extender, an increase in the number average molecular weight from 33 000 to 72 000 g moU for copolymers with butylene succinate and butylene adipate units was reported. ... 

DADC may be polymerised industrially with small amounts of other miscible Hquid monomers. Some acryflc ester monomers and maleic anhydride may accelerate polymerisation. Copolymerisation with methacrylates, diaHyl phthalates, triaHyl isocyanurate, maleates, maleimides, and unsaturated polyesters are among the examples in the early Hterature. Copolymers of DADC with poly-functional unsaturated esters give castings of high clarity for eyeglass lenses and other optical appHcations (20). 

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