イソシアヌレート架橋ポリウレタンの粘弾性

概要

論文の詳細を見る
Isocyanurate crosslinked polyurethanes were prepared from poly (oxypropylene glycol). Physical properties such as gel fraction, swelling ratio, density, glass transition temperature, and stress relaxation were measured and compared with those of TMP-cured and MOCA-cured polyurethanes. Ten-second modulus vs. temperature relationships obtained from stress relaxation data revealed that isocyanurate crosslinked polyurethanes had normal temperature dispersions as in the case of TMP-cured ones, and that glass transition region was shifted to lower temperatures and had more gentle slope with increasing flexibility of diisocyanate segment. On the other hand, MOCA-cured polyurethanes show fairly broad glass transition region and have high rubbery modulus. Stress relaxation curves were superimposed successfully and master curves were obtained. Temperature dependence of log a_T obayed WLF equation. The distribution curves of relaxation times at reference temperature Ts were calculated, which showed that isocyanurate crosslinked polyurethanes behaved as typical amorphous polymer networks as in the case of TMP-cured ones but had higher wedge-type spectra than those of the latter. MOCA-cured polyurethanes, in contrast, show remarkably gentle slope in transition region. Log a_T referred to Tg vs. (T-Tg) relationships were plotted between the curve for polar polymer and that for non-polar polymer.
近畿大学の論文
1973-12-01