Polyglycolide-<?0-caprolactone

Poly (e-caprolactone), poly lactides, and polyglycolides have quite unusual properties of biodegradability and biocompatibility. The majority of polymers used in the biomedical field to develop implants, sutures, and controlled drug-delivery systems are the aforesaid resorbable polyesters produced by ring-opening polymerization of cyclic (di)esters. 

Accordingly, the first part of this chapter deals with the copolymerization of an 8-caprolactone/glycolide mixture that is rich in glycolide wherein the critical stage of the copolymerization is conducted in the solid state below 200°C, which is well below the 225°C of tiie of polyglycolide. ... 

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],... 

Polycaprolactone (PCL) is a biodegradable semicrystalline polyester that is synthesized from cap-rolactone using staimous octoate in a similar maimer to polylactide or polyglycolide. PCL has a very low modulus of around 50 ksi since it has a low Tg of —60 C. PCL degrades very slowly, and therefore, it is usually not used as a homopolymer. Caprolactone, however, is copolymerized with glycolide to make a flexible suture material (trade name Monocryl). ... 

Absorbable suture materials are catgut (collagen derived from sheep intestinal submucosa), reconstituted collagen, polyglycolide (e.g., Dexon , Dexon II , Dexon S ), poly(glycolide/lactide) random copolymer (e.g.. Vicryl ), antimicrobial-coated Vicryl (Vicryl Plus ), poly-/ -dioxanone (e.g., PDS , PDSII PDS Plus), poly(glycolide/trimethylene carbonate) block copolymer (e.g., Maxon ), poly(glycolide/e-caprolactone) (e.g., Monocryl ,... 

Degradable polymers such as polylactide (PLA), polyglycolide (PGA), poly(e-caprolactone) (PCL), poly(trimethylene carbonate) (PTMC) and poly (para-dioxanone) (PDO) have been widely investigated, and approved by FDA for use in the biomedical field (Middleton and Tipton, 2000). Table 4.1 presents the stmctures and thermal properties of these polymers. 

Bioresorbable linear aliphatic polyesters (e.g., polyglycolide, polylactide, polycaprolactone, polyhydroxybutyrate) and their copolymers within the aliphatic polyester family like poly(glycolide-L-lactide) copolymer and poly(glycolide-E-caprolactone) copolymer. 

As widely usable biodegradable materials, PLA is found to exhibit too hard and too brittle characters. The weakness might be improved when a polymer with lower glass transition temperature is used together [18]. Polyfe-caprolactone) (PCL) and poly(glycolic acid) (PGA), also known as polyglycolide, are two other... 

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