Oligoester glycol

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... 

Like PU TPE, blends of thermoplastic polyurethanes and polyamide-12 (PA-12) have been studied by Polosmak and co-workers [61]. They have mixed two types of thermoplastic polyurethane (TPU) based on oligoether (polytetramethylene oxide, molecular weight, 1000) and oligoester (polyethylene butylene glycol adipate, molecular weight, 2000) and PA 12 were characterised by IR spectra and thermal analysis. IR spectra of TPU, PA-12 and their blends show that in amide one (Al) carbonyl absorbancy is seen to split [55] into two main bands with maxima at 1705 and 1730 cm 1. At 1730 cm 1,... 

This part of the work is devoted to the study of adhesive joint formation based on urethane polymer mixtures with free NCO groups. The materials under investigation were adhesives obtained from toluylene diisocyanate (TDI) and hydroxyl-containing polyesters. The hydroxyl-containing components were ohgooxypropylenetriols (L-3003 and P-2200 oligoester, the product of reaction of diethylene glycol, trimethylolpropane and adipic acid interaction). 

Glycolysis consists of the transesterification of PET and the destruction of its polymer chain, resulting in the decrease of its MW. When glycols are used for the depolymerisation of PET, the oligomers obtained have two hydroxyl end groups, i.e., oligoester diols are formed. 

Oligoesters with acrylic ester end groups can be polymerized either directly or in blends with other monomers. The synthesis of the oligoesters from dicarboxylic acid and glycols in Fig. 7 has already been described with similar molar relationships for epoxide and isocyanate curing agents. The hydroxylic end groups are saturated with acrylic acid esters and then polymerized. 

Maleic acid and phthalic acid are used as oligoester components together with bivalent alcohols (e.g., ethylene glycol, 1,4-butanediol) as co-condensation partners. Crosslinking is achieved by copolymerization of styrene, vinyl acetate, diallyl phthalate, acrylonitrile or acrylic ester. Cyclic structures impart a higher glass transition temperature. The aliphatic glycols in the... 

Relaxation in pol3nners flexibilized with Empol differs only slightly from that in the system modified with sebacic acid-neopentyl glycol oligoester, even though there are considerable differences in the chemical structures of the two flexibilizers. 

Preparation of macrocyclic oligoesters has so far been achieved by two major approaches [1]. One is condensation of dibasic acid derivatives with glycols or dihalides, and the other is depolymerization of linear polyesters. However, the yield of macrocyclic oligoesters by these methods are generally unsatisfactory, and moreover, the product distribution is mostly controlled by intrinsic thermodynamic factors. In order to overcome these drawbacks, a new procedure using tin derivatives as covalent templates has been proposed recer tly for the synthesis of some macrocyclic tetra-esters [2]. 

Oxyacids. In 1985, a lipase-catalyzed polymerization of 10-hydroxydecanoic acid was reported. The monomer was polymerized in benzene using poly(ethylene glycol) (PEG)-modified lipase solnble in the medium to give an oligoester with DP more than 5 (74). 

By direct esterification or transesterification of dicarboxylic acids with various glycols in the presence of monocarboxylic acids and alcohols, oligoesters are produced. As catalysts, benzene- and toluenesulfonic acids are used as well as carboxylic acids salts or tetrabutoxytitane. The main use of these is in the plasticizing of various plastics [24,25]. 

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