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Effect of hydration on the mechanical properties, composition and molecular weight of polyurethaneureas
Author(s) -
Wu Limin,
You Bo,
Li Dan,
Qian Feng
Publication year - 2000
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/1097-0126(200012)49:12<1609::aid-pi559>3.0.co;2-x
Subject(s) - molecule , hydrogen bond , polyurethane , materials science , chemical engineering , chemical structure , oxide , chemical composition , polymer chemistry , leaching (pedology) , chemistry , composite material , organic chemistry , environmental science , soil science , engineering , soil water
Though there exist extensive studies on the relationship between structure and properties of polyurethane [PU] and polyurethaneurea [PUU], practically no fundamental information is available on hydrated PUU. In this study, the PUU films were immersed in saline solution (0.9 wt% NaCl, 37 °C) for periods of up to 60 days and evaluated by the change in static and dynamic mechanical properties, composition and hydrogen‐bonding structure. It was found that immersion in saline solution greatly increased the average molecular weight and degree of phase separation, resulting in an increase in mechanical strength and decrease in flexibility. The increase in average molecular weight is thought to come from chain extension or crosslink reactions inside the molecules and between molecules, and from leaching out of poly(tetramethylene oxide) (PTMO) oligomers. FT‐IR analysis indicated that water molecules did not obviously change the hydrogen‐bonding structure of PUU. © 2000 Society of Chemical Industry