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Structure and mechanical properties of thermoplastic polyurethane, based on hyperbranched polyesters
Author(s) -
Cao Qi,
Cai Yuanli,
Jing Bo,
Liu Pengsheng
Publication year - 2006
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/app.24779
Subject(s) - differential scanning calorimetry , materials science , thermoplastic polyurethane , copolymer , polyurethane , elongation , polyester , thermoplastic elastomer , crystallization , thermoplastic , polymer chemistry , dynamic mechanical analysis , composite material , chemical engineering , polymer , elastomer , ultimate tensile strength , thermodynamics , physics , engineering
A series of hyperbranched polyurethane (HB‐PU) were synthesized using hyperbranched polyester as a precursor. Morphology of these HB‐PU films was investigated using atomic force microscopy and wide‐angle X‐ray diffraction; it's molecular dynamics was studied by dynamic mechanical analysis. FTIR studies showed that hard segments get more aggregated to form domains in the HB‐PU block copolymer as hard segment content increases. Such domain formation has a significant influence on the mechanical and thermomechanical properties of HB‐PU, such as maximum stress and elongation at break. Especially, maximum stress and elongation at break increased significantly at 25 wt % of hard segment content, and the highest loss tangent was observed at the same composition. Heat of crystallization as measured by differential scanning calorimetry is also dependent on the hard segment content, and the control of hard segment content in PU block copolymers is very important in determining their physical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5266–5273, 2006