DECALACTONE COPOLYMER

The mechanisms of biodegradation of polylactide, polycaprolactone and caprolactone copolymers with dilactide copolymer, valerolactone copolymer, and decalactone copolymer in the rabbit were shown to be qualitatively similar. The rate of the first stage of the degradation process, non enzymatic random hydrolytic chain scission, was found to vary by an order of magnitude and was dependent on morphological as well as chemical effects. 17 refs. 

Stannous octoate has the advantage of having been used to prepare polymers (Silastic, Capronor) for which substantial toxicological data are now available (6,48). Stannous octoate-initiated polymerization has been used to prepare copolymers of e-caprolactone with other lactones, including diglycolide, dilactide, 6-valerolactone, e-decalactone, and other alkyl-substituted e-caprolactones. Conducting... 

Evidence of enzymatic degradation in vivo was first observed with a random copolymer of e-caprolactone and e-decalactone (93). 

The chain scission and weight loss of a semicrystalline copolymer with 8 mol % e-decalactone was almost identical to that of PCL and was clearly nonenzymatic. When the proportion of e-decalactone was... 

Decalactone-co Caprolactone. Copolymers of -decalactone and caprolactone were prepared in bulk at 130°C with stannous octoate as catalyst. For accurate determinations of copolymer compositions H-labeled -caprolactone was used. The copolymerization parameter for caprolactone was found to be 2.2, whereas the parameter for -decalactone was practically zero. The latter finding agrees with homopolymerization experiments which established that -decalactone polymerizes extremely slowly to low molecular weight products ([n] 0.4 dl/g). 

Copolymers of e-decalactone and e-caprolactone represent useful implant materials only when the decalac-tone content is very low. A change of the decalactone content from 8 to 13 mole-% has a pronounced effect on the biodegradation behavior of implants as shown by the data of Table II and Fig. 10. 

Fig. 10 - In vivo degradation of e-decalactone-e-caprolactone (DL/CL) and dilactide-e-caprolactone (LA/CL) copolymers in tube form. Change in intrinsic viscosity of excised implants.

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