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Impact modification of lactic acid based poly(ester‐urethanes) by blending
Author(s) -
HiljanenVainio Mari,
Kylmä Janne,
Hiltunen Kari,
Seppälä Jukka V.
Publication year - 1997
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(19970307)63:10<1335::aid-app13>3.0.co;2-3
Subject(s) - copolymer , materials science , polymer chemistry , lactide , miscibility , lactic acid , dynamic mechanical analysis , biodegradable polymer , izod impact strength test , polymer , composite material , ultimate tensile strength , biology , bacteria , genetics
Branched biodegradable poly(ester‐urethane)(PEU) was blended with two elastic biodegradable copolymers in proportions 5, 10, 15, and 20 wt % to investigate their effect on this hard and brittle polymer. Copolymer of L‐lactide and ϵ‐caprolactone, P(L‐LA50/CL50), was synthesized by ring‐opening polymerization and the other elastic poly(L‐lactic acid‐ co ‐ϵ‐caprolactone)urethane, P(LA50/CL50)U, was prepared by direct polycondensation of L‐lactic acid and ϵ‐caprolactone, followed with urethane bonding. In addition, four elastic biodegradable copolymers, three of them P(L‐LA/CL) and one P(LA/CL)U, were blended with linear PEU to investigate their modifying effect on PEU. These compositions studied were 10, 15, and 20 wt % of P(L‐LA40/CL60), P(L‐LA60/CL40), P(L‐LA80/CL20), and P(LA40/CL60)U in PEU. Blending was done in a batch mixer. PEU became more ductile when blended with P(L‐LA/CL) and P(LA/CL)U, and its impact resistance improved markedly. In general, an addition of 15 wt % of copolymer appeared to give the most desirable mechanical properties. Moreover, the more L‐lactide in the P(L‐LA/CL) copolymer, the better was the miscibility of the blends, as shown by dynamic mechanical thermal analysis (DMTA) and scanning electron microscopy (SEM). One P(L‐LA/CL) was also blended with poly(DL‐lactide) (PDLLA) to see if the dispersion of rubbery copolymer particles was the same in PDLLA and PEU. A well‐known commercial nonbiodegradable rubber [styrene/ethylene/butylene copolymer (SEBS)] was blended with linear PEU to compare its effect on impact strength. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1335–1343, 1997