Premium
Structural and Mechanical Properties of Polybutadiene‐Urethane Elastomer
Author(s) -
Chiu WenYen,
Chen LeoWang,
Lee ShyhHwang
Publication year - 1987
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.198700010
Subject(s) - polybutadiene , chemistry , ultimate tensile strength , elastomer , copolymer , polymer chemistry , polymerization , elongation , dynamic mechanical analysis , phase (matter) , hydroxyl terminated polybutadiene , polyester , chemical engineering , polymer , composite material , organic chemistry , materials science , engineering
A series of polyurethanes based on hydroxyl‐terminated polybutadiene (HTPBD) and cured with Bis ‐(‐hydroxy ethyl)‐terephthalate (BHET) have been synthesized. Mechanical, microscopic and kinetic studies were carried out to elucidate the structure‐property relationships from the view point of phase separation. We studied the effects of the polymerization method, varying the hard to soft segment ratio and changing the hard‐segment domain structure on the properties of the subject materials. Dynamic mechanical responses showed that the Tg of the soft‐segment at −60° C was independent of the hard‐segment content, which indicates that the copolymers were well phase separated. A higher hard‐segment content brought about a slight increase in the modulus, a moderate increase in the tensile strength and a decrease in the ultimate elongation. The size of the hard‐segment domain, as estimated from electron micrographs, ranged from 60A to 100A. It was observed that a higher content of hard‐segments causes an increase in the hard‐segment domain size. In addition, a general survey of the reaction rate indicated that BHET is less reactive with diphenyl methyl diisocyanate (MDI) than with HTPBD.