02096nas a2200229   4500008004100000022001400041245020100055210006900256260006700325490000800392520112200400653001801522653001501540653003801555653002601593653003201619100002201651700002401673700002301697700002501720856012101745       2016                        eng d  a0021-899500aSynthesis and characterization of well-defined random and block copolymers of epsilon-caprolactone with l-lactide as an additive for toughening polylactide: Influence of the molecular architecture0 aSynthesis and characterization of welldefined random and block c  a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcAPR0 v1333 a<p>Well-defined multiarmed star random and block copolymers of epsilon-caprolactone with l-lactide with controlled molecular weights, low polydispersities, and precise numbers of arms were synthesized by the ring-opening polymerization of respective cyclic ester monomers. The polymers were characterized by H-1-NMR and C-13-NMR to determine their chemical composition, molecular structure, degree of randomness, and proof of block copolymer formation. Gel permeation chromatography was used to establish the degree of branching. Star-branched random copolymers exhibited lower glass-transition temperatures (T-g's) compared to a linear random copolymer. When the star random copolymers were melt-blended with poly(l-lactic acid) (PLA), we observed that the elongation of the blend increased with the number of arms of the copolymer. Six-armed block copolymers, which exhibited higher T-g's, caused the maximum improvement in elongation. In all cases, improvements in the elongation were achieved with no loss of stiffness in the PLA blends. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43267.</p>10abiodegradable10acopolymers10adifferential scanning calorimetry10amechanical properties10aring-opening polymerization1 aDeokar, Megha, D.1 aIdage, Susheela, B.1 aIdage, Bhaskar, B.1 aSivaram, Swaminathan  uhttps://library.ncl.res.in/content/synthesis-and-characterization-well-defined-random-and-block-copolymers-epsilon-0