Copolymer lactic acid-trimethylene carbonate

Synthesis of Copolymers of Lactic Acid Trimethylene Carbonate... 

Glycolide L-lactide copolymers Lactide trimethylene carbonate copolymers Lactide tetramethylglycolide copolymers Lactide a-valerolactone copolymers Methacrylate N-vinyl-pyrrolidone copolymers Lactic acid ethylene oxide copolymers... 

POLYd, 3-TRIMETHYLENE CARBONATE) AND THEIR COPOLYMERS WITH d,l-LACTIC acid ANDE-CAPROLACTONE... 

The most important polymer on the market today is PLA, which upon degradation yields lactic acid, a natural metabolite in the human body [79]. The formation of natural metabolites should be advantageous as the body has routes to eliminate them. Other commercial degradable materials are polyparadioxane [238], the copolymer of glycolic acid and trimethylene carbonate [239], which does not give natural metabolites when degraded. Their most important charac-... 

Owing to its hydrolytic instability, initially, its use was limited. Currently, polyglycolide and its copolymers poly(lactic-co-glycolic acid) with lactic acid, poly(glycolide-co-caprolactone) with e-caprolactone, and poly(glycolide-co-trimethylene carbonate) with trimethylene carbonate) are widely used to develop synthetic absorbable sutures that were marketed under the trade name of Dexon and are now sold as Surgicryl [61],... 

PHA chemical modification can be done via block copolymerizadon and grafting reactions, chlorination, cross-linking, epoxidation, hydroxyl and carboxylic acid functionalization, etc. (Chen et al. 2009 Wu et al. 2008 Li et al. 2003 Loh et al. 2007). A common approach to confer toughness to PLA is the use of a flexible monomer or macromolecules for copolymerization with lactide to form PLA-based random or block copolymers. Reported PLA-based block copolymers include diblock, triblock, and multiblock copolymers, such as poly(L-lactic acid) (PLLA)-polycaprolactone (Jeon et al. 2003), poly(ethylene glycol)-PLLA (Chen et al. 2003), poly(trimethylene carbonate)-PLLA (Tohru et al. 2003), and PLA-PBS-PLA. 

Bioresorbable copolymers between linear aliphatic polyesters in (1) and monomers other than Unear aUphatic polyesters like, poly(glycoUde-trimethylene carbonate) copolymer, poly(L-lactic acid-L-lysine) copolymer, tyrosine-based polyarylates or polyiminocarbonates or polycarbonates, poly(DJL-lactide-urethane), and poly(ester-amide). 

The six-membered lactide, a cyclic dimer of lactic acid, was polymerized by lipase as a catalyst in bulk to yield the corresponding polylactide with an of up to 126000 with a relatively low yield. The D,L-lactide gave a higher molecular weight compared to the D,D- and L,L-lactides [45,46]. The L,L-, D,D-, and D,L-lactides were copolymerized with trimethylene carbonate by porcine pancreatic lipase (PPL) to produce random copolymers having molecular weights of up to 21000 [47]. 

Biodegradable synthetic polymers such as poly(glycolic acid), poly(lactic acid) and their copolymers, and copolymers of trimethylene carbonate and glycolide have been used in a number of clinical applications [26-30]. The major applications include resorbable sutures, drug delivery systems and orthopaedic fixation devices such as pins, rods and screws [31, 32]. 

---