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Preparation and characterization of thermoplastic polyurethane elastomer and polyamide 6 blends by in situ anionic ring‐opening polymerization of ϵ‐caprolactam
Author(s) -
Hou Lianlong,
Liu Hongzhi,
Yang Guisheng
Publication year - 2006
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.20589
Subject(s) - materials science , caprolactam , differential scanning calorimetry , thermoplastic polyurethane , composite material , flexural modulus , thermoplastic elastomer , polyamide , glass transition , flexural strength , elastomer , dynamic mechanical analysis , polymerization , ultimate tensile strength , crystallinity , compatibilization , in situ polymerization , izod impact strength test , copolymer , polymer chemistry , polymer , polymer blend , physics , thermodynamics
The blends of thermoplastic polyether‐based urethane elastomer (TPEU) and monomer casting polyamide 6 (MCPA6) were prepared using ε‐caprolactam (CL) as a reactive solvent, and CL sodium as a catalyst at various TPEU contents (2.5–15 phr by weight). In situ anionic ring‐opening polymerization and in situ compatibilization of TPEU/MCPA6 blends were realized in one step. The dissociated TPEU chains acted as macroactivator to initiate MCPA6 chain growth from the TPEU chains. The formed block copolymers (TPEU‐ co ‐MCPA6), which have been confirmed by Fourier transform infrared spectroscopy and 1 H‐NMR analysis, improved the compatibility between TPEU and MCPA6. In addition, both differential scanning calorimetry and dynamic mechanical analysis studies revealed that the crystallinity temperature, melting temperature, the degree of crystallization, and the glass‐transition temperature of MCPA6 component remarkably shifted to a low temperature with increasing TPEU content. Mechanical properties demonstrated that the impact strength and the elongation‐at‐break of the blends significantly increased with the content of TPEU, whereas a progressive decrease occurred in tensile strength, flexural strength, and flexural modulus. WAXD spectra showed that only α‐form crystal of PA6 component existed in the TPEU/MCPA6 blends. Furthermore, scanning electron microscopes (SEM) of the cryo‐fractured surfaces confirmed a substantially improved compatibility, and reflected a seemly single‐phase morphology. POLYM. ENG. SCI., 46: 1196–1203, 2006. © 2006 Society of Plastics Engineers