<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Pandey, Asutosh K.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Copolymerzation of L,L-lactide with epsilon-caprolactone by using novel zinc L-proline organometallic catalyst</style></title><secondary-title><style face="normal" font="default" size="100%">E-Polymers</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">DEC</style></date></pub-dates></dates><publisher><style face="normal" font="default" size="100%">EUROPEAN POLYMER FEDERATION</style></publisher><pub-location><style face="normal" font="default" size="100%">1, QUAI LEZAY-MARNESIA, F067000 STRASBOURG, FRANCE</style></pub-location><pages><style face="normal" font="default" size="100%">139</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Copolyesters based on L, L-lactide (LA) and e-caprolactone (CL) with different LA: epsilon-CL ratios were synthesized by ring opening polymerization using zinc (L-proline) as a catalyst. Ring opening polymerization results in random P(L, L-lactide-epsilon-caprolactone) copolymers of molecular weights between 9,800 to 30,000 and block copolymer up to 51,800 Da. H-1 NMR spectroscopy analysis was used for calculation of monomer incorporation in the copolymer. FT-IR spectra were used to differentiate between random and block copolymer using carbonyl region splitting. C-13 quantitative NMR spectroscopy analysis coupled with information from TGA and DSC allowed determination of the polymer structure. Copolymers (CP-1, CP-2 and CP-3) prepared by ROP are random copolymer (h &amp;gt; 1), while CP-4 prepared by ROP (sequential addition of epsilon-caprolactone and L, L-lactide) has a multi block character (h &amp;lt; 1). The LA number-average sequence length (L-LA) decreased from 14 to 5 for LA-CL 80:20 to 50:50 copolymers prepared by ROP. The copolymer (CP-4) prepared by sequential addition showed the number-average sequence length (L-LA) to be 83.0.&lt;/p&gt;</style></abstract><custom3><style face="normal" font="default" size="100%">Foreign</style></custom3><custom4><style face="normal" font="default" size="100%">0.574</style></custom4></record></records></xml>