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Polyurethane–polystyrene interpenetrating polymer networks synthesized at low temperature: Effect of crosslinking level
Author(s) -
Lee Doo Sung,
Park Tae Sung
Publication year - 1991
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.1991.070430309
Subject(s) - miscibility , polyurethane , materials science , polystyrene , polymer , interpenetrating polymer network , polymer chemistry , polymerization , photopolymer , chemical engineering , composite material , engineering
Interpenetrating polymer networks (IPNs) of polyurethane (PU)–polystyrene (PS) containing 50 wt % PU were synthesized at low temperature with varying crosslink density of each component. PU was polymerized first, followed by the photopolymerization of PS at low temperature (0 and 40°C). The theoretical molecular weight between crosslink ( M̄ c ) of PU ranged from 8200 to 2050, and the M̄ c of PS varied from linear to 2000. The degree of mixing of the components in these IPNs was investigated using dynamic mechanical analysis, electron microscopy, and density measurement. The degree of mixing increased with decreasing M̄ c and/or synthesis temperature. The crosslink density variation at low synthesis temperature is more effective in enhancing the miscibility of IPN than at high synthesis temperature, because both the temperature and crosslink density can affect the polymer chain mobility during the synthesis. The variation of PU network crosslink density shows the better effect in increasing the miscibility of IPN than that of the PS network. The morphology and the density behavior agree well with the dynamic mechanical result.