Unsaturated oligoesters

The introduction into the process of esterification or transesterification of some unsaturated dicarboxylic acids (or their anhydrides) leads to the production of unsaturated oligoesters, also called polyester resins. Mixtures of saturated and un- 

Also interesting is the synthesis of unsaturated polyesters by copolycondensation of oligoCeihylene terephthalate) with maleic acid. The raw material oligo(ethylene terephthalate) for this process is obtained by degradation of residues coming from the textile industry [48]. Thus, high-flexibility lacquers [49], adhesives for the footwear industry [50], textile additives, and ingredients for lubricants and rubber have been obtained [51—55]. 

A group of acid-terminated unsaturated oligoesters having molecular weights of 500 to 1400 and incorporating a lactone as co-reactant with an aromatic, or partially or fully hydrogenated aromatic, dicarboxylic acid and an aliphatic diol are valuable plasticizers for poly(vinyl chloride) [56-59]. 

Polyfunctional oxazoline-terminated unsaturated oligoesters are useful in preparing coatings, caulks, impregnants, adhesives for textiles, leather, plastics, wood, and metals, and binding agents for pigments, fibers, and nonwoven fabrics [60-67]. 

The vinyl monomers used to effect crosslinking include styrene [68-70], or a combination of styrene with other copolymerizable monomers, such as a-methylstyrene, methyl acrylate, methyl methacrylate [71], diallyl phthalate [72], triallylcyanurate, and so forth. 

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This brief description of the properties of unsaturated oligoesters indicates that they are promising starting materials for the production of free-foamed gas-filled polymeric materials. The very interesting possibilities of using composite foams based on OEM and commercial thermoplastics or elastomers should also be mentioned. 

All-trans unsaturated ester oligomers have been synthesized by lipase-catalyzed polymerization of diesters of fumaric acid and 1,4-butanediol.217 No isomerization of the double bond was observed, as opposed to the extensive isomerization found during chemical polycondensations. Crystallinity was found in the enzymatically formed unsaturated oligoesters prepared in acetonitrile, whereas industrial unsaturated polyesters are amorphous. 

Anisimov, Y. M., and Grekhova, O. B., Initiation of curing and copolymerization of unsaturated oligoesters resins with styrene, Russian J. Appl. Chem., 67, 1034, 1994. Nisimov, G. B., and Grekhova, G. B., Hardening and copolymerization of unsaturated oligoester resins with methyl methacrylate and copolymer composition, Russian J. Appl. Chem., 67, 1719, 1994. 

Unsaturated oligoesters based on novolak-type phenol-formaldehyde and toluene-formaldehyde or xylene-formaldehyde resins... 

The effect of incorporating p-hydroxybenzoic acid (I) into the structures of various unsaturated polyesters synthesised from polyethylene terephthalate (PET) waste depolymerised by glycolysis at three different diethylene glycol (DEG) ratios with Mn acetate as transesterification catalyst, was studied. Copolyesters of PET modified using various I mole ratios showed excellent mechanical and chemical properties because of their liquid crystalline behaviour. The oligoesters obtained from the twelve modified unsaturated polyesters (MUP) were reacted with I and maleic anhydride, with variation of the I ratio with a view to determining the effect on mechanical... 

The production of oligoesters with urethanic groups and unsaturated acrylic type and groups is based on the following two reactions ... 

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