Poly caprolactone

PCL is commonly used in the manufacture of polyurethanes because of its imparting good water, oil, solvent, and chlorine resistance to the polyurethane produced. In 1934, Carothers et al. [103] prepared epsilon-caprolactone for the first time. Under the condition of heat epsilon-caprolactone is converted to a polyester of high molecular weight. The 1965, Magnus [104] published details of his study of effects of components and varying -NCO/-OH or -NCO/-NH2 group ratio on the low-temperature properties, hydrolytic and heat stability, and solvent and chemical resistance of the polyurethane elastomers. It was found that 

Carboxylates are much weaker nucleophiles than alkoxides, and they are unable to give rise to an 0-acyl scission upon attack of another lactone molecule. The consequence is that once the propagation site is a carboxylate, it stays as such. Only if the probability of 0-acyl scission is equal to unity can one be sure that all propagation sites are alcoholates, even at high conversions. At various degrees of conversion, all experimental data showed that the propagating sites are alkoxides until the end of the reaction. 

Normally, the polymerization is conducted at low temperature because the activation energy for chain growth is generally rather low, which means that the variation of the rate of propagation with temperature is not very large. 

The polymerization was stopped with a few drops of acetic acid at rather low conversion (30%), after a period of 2-10 min, depending upon the desired molecular weight. The monomer conversion was determined from the size exclusion chromatography (SEC) diagrams obtained on polymerization mixtures [107]. 

Chemical and Physical Properties The major physical and mechanical properties of poly(caprolactone) are summarized briefly in Table 1.5. Its physical and mechanical properties depend mainly on its molecular weight and crystallinity. In general, aromatic and some polar solvents such as benzene, toluene, cyclohexanone, dichloromethane and 2-nitropropane are good solvents for PCL. Water, alcohols, petroleum ether, diethylether are poor solvents for PCL. PCL can be slightly soluble in acetonitrile, acetone, 2-butanone, ethyl acetate and dimethylformamide. 

Cellophane multilayer films have prepared by coating with PCL and chitosan (65). The effects on barrier and mechanical properties were investigated. The multilayer films exhibit a much better water vapor barrier than cellophane and have high oxygen barriers. The mechanical properties of the multilayer films are slightly decreased. 

Sarazin, J. Li, and Z. Yuan, Microporous articles comprising biodegradable medical polymers, method of preparation thereof and method of use thereof, US Patent 8 007 823, assigned to Corporation de I Ecole Polytechnique de Montreal (Montreal, CA), August 30, 2011. 

Prasad, Polishing pad comprising biodegradable polymer, US Patent 7 264 641, assigned to Cabot Microelectronics Corporation (Aurora, IL), September 4,2007. 

Coates, Syndiotactic poly(lactic acid), US Patent 6608 170, assigned to Cornell Research Foundation, Inc. (Ithaca, NY), August 19, 2003. 

Kakida, and S. Obuchi, Biodegradable resin composition, US Patent 7714048, assigned to Toho Chemical Industry Co., Ltd. (Tokyo, JP), May 11, 2010. 

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Zhenyang, Y., Jingbo, Y., Shifeng, Y., Yongtao, X., Jia, M. and Xuesi, G. 2007. Biodegradable poly(L-lactide)/poly(3-caprolactone)-modified montmorillonite nanocomposites Preparation and characterization. Polymer 48 6439-6447. 

Pantoustier, N., Alexandre, M., Degee, P, Calberg, C., Jerome, R., Henrist, C., et al. (2001). Poly(3-caprolactone) layered silicate nanocomposites effect of clay surface modifiers on the melt intercalation process. e-Polymer, 9, 1-9. 

Sorrentino, A., Gorrasi, G., Tortora, M., Vittoria, V., Costantino, U., Marmottini, F., et al. (2005). Incorporation of Mg-Al hydrotalcite into a biodegradable poly(3-caprolactone) by high energy ball milling. Polymer, 46, 1601-1608. 

Khan F, Valere S, Euhrmann S, Arrighi V, Bradley M. Synthesis and cellular compatibility of multi-block biodegradable poly(3-caprolactone)-based polyurethanes. J Mater... 

Singh NK, Singh SK, Dash D, Purkayastha BPD, Roy JK, Maiti P. Nanostructure controlled anti-cancer drug delivery using poly(3-caprolactone) based nanohybrids. J Mater Chem 2012 22 17853-63. 

Block copolymers based on hard segments of crystallizable poly((R)-3-hydroxybutyrate-co-(R)-3-hydroxyvalerate) (PHBV) and switching segments of hyperbranched three-arm poly(3-caprolactone) were proposed by Xue et al. (2010) as biodegradable SMPs for fast, self-deploying stents. Those containing copolymer with 25 wt% PHBV demonstrated almost complete self-expansion at 37°C within just 25 s, which is much faster than current self-deployable stents. 

Bechara, S. L., A. Judson, and K. C. Popat. 2010. Template synthesized poly(3-caprolactone) nanowire surfaces for neural tissue engineering. Biomaterials 31 3492-501. 

Ghasemi-Mobarakeh, L., Prabhakaran, M.P., Morshed, M., Nasr-Esfahani, M.-H., and Ramakrishna, S. (2008) Electrospun poly(3-caprolactone)/gelatin nanofibrous scaffolds for nerve tissue engineering. /. Biomater., 29, 4532-4539. 

Biodegradation of poly(3-caprolactone)/starch blends and composites in composting and culture environments the effect of compatibilization on the inherent biodegradability of the host polymer. Carbohydr. Res., 338 (17), 1759-1769. 

Synthesis and structure of poly(3-caprolactone)/synthetic montmo-rillonite nano-intercalates. Eur. Polym. J., 40 (11), 2591-2598. 

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