Copolyesters graft

Fig. 37 Synthesis of graft copolyesters by the grafting from approach...

S.M. Aharoni, and D. Masilamani, Process for preparing extended chain polyesters and block or graft copolyesters, US Patent 4568720, assigned to Allied Chemical Corporation, February 4,1986. 

When the grafting of MMA was initiated by polyenolate 94, derived from poly(vinyl acetate) (equation 68), Inoki and coworkers applied deuterolysis to show that 26% of the acetate units were lithiated by 0.3 equivalent of LDA with respect to these units and, thus, that 87% of the original lithium was incorporated into the copolyester °. The average number of PMMA grafts was in the range of 1 to 7, and the average number of... 

Blends of PET/HDPE have been treated previously in the literature [157, 158]. These are immiscible, but the addition of compatibilizers improves the mechanical properties of the blend, such as styrene-ethylene/butylene-styrene (SEBS) and ethylene propylene diene monomer (EPDM) [157], MAH [158], Poly(ethylene-stat-glycidyl metha-crylate)-graft-poly(acrilonitrile-stat-styrene) (EGMA), poly (ethylene acrylic acid), and maleated copolymers of SEBS, HDPE, ethylene-propylene copolymer (EP). The addition of compatibilizers modifies the rheological properties of blends of PET with HDPE, in such a way that increases in viscosity are observed as the component interactions augment. Changes in crystallization of PET were evaluated in blends with Polyphenylene sulfide (PPS), PMMA, HDPE aromatic polyamides, and copolyesters [159]. 

Segmented copolyester as hydrophilic substrates based on end-grafted polyethylene glycol (PEG)... 

Radiation-sterilizable, segmented copolyester made by end-grafting radiostable aromatic prepolymers with glycolide... 

Gel-forming (GF) absorbable copolyesters made by end-grafting one or more cyclic monomer onto a polyalkylene glycol, such as polyethylene glycol for use in tissue repair and controlled delivery of bioactive agents... 

Copolyesters Made by End-Grafting Cyclic Monomers onto... 

For this group of new polymers, a prepolymeric polyalkylene succinate was prepared, end-grafted with e-caprolactone (CL) and/or trimethylene carbonate (TMC), and the product was then end-grafted with glycolide or a gly-colide-rich mixture of monomers. Discussion in this chapter is focused on these copolyesters based on polytrimethylene succinate. 

T3 ical Polymer Properties of Segmented Copolyesters of End-grafted Polytrimethylene Carbonate (PTS) ... 

Similar graft copolymers were also obtained by esterification of the carboxy-terminal groups of PHAs with cellulose hydroxyl functions. These copolyesters showed a slightly increased melting transition when compared with a physical mixture of PHB and cellulose (Yalpani et al. 1991). 

Aliphatic polyesters, copolyesters, and natural macromolecules (mainly collagen, elastin, fibrin, chitosan, and hyaluronic acid (HA)), as well as their blends, have also been used to prepare polymeric-based vascular grafts with tuned mechanical properties. Couet et al. reported a comprehensive overview of materials that have been explored as scaffolds for vascular tissue engineering [59]. The analysis of the mechanical behavior of non-PU-based vascular grafts is beyond the scope of this chapter. 

Branched copolymers have also been synthesized by the preparation of macromonomers. Various types of methacrylate-functionalized macromonomers have been reported in the literature for the preparation of graft and star copolyesters. The reaction scheme used for the preparation of the macromonomers is depicted in Figure 4.11. 

Li, H., Jerome, R., and Lecomte, P. (2008) Amphiphilic sun-shaped polymers by grafting macrocyclic copolyesters with PEG. Macromolecules, 41,650-654. 

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