聚丁二烯型聚氨酯/环氧树脂互穿聚合物网络的研究

POLYBUTADIENE-BASED POLYURETHANE/EPOXY INTERPENETRATING NETWORKS

用同步法合成了聚丁二烯型聚氨酯/环氧树脂互穿聚合物网络[PU(HTPB)/EP-IPN].FTIR分析表明两组分网络间存在一定的化学结合。动态力学温度谱表明该IPN具有两个T_g,与纯PU(HTPB)和EP比较,两个T_g均内移,但T_(g1)内移很小,T_(g2)内移程度大且处于PU(HTPB)硬段转变和EP的T_g之间,证明交联结构的互锁主要存在于PU(HTPB)的硬段与EP网络之间。透射电镜研究表明,组分比对IPN的形态有显著影响,随着EP含量的增加,微区尺寸增大,并出现相转换,相应的IPN材料逐步由补强橡胶转变为增韧塑料。在组分比相同的情况下,全IPN的力学性能优于半IPN和线型共混物。

Interpenetrating polymer networks of polybu-tadiene-based polyurethane/epoxy were synthesized by simultaneous polymerization. FTIR spectra showed that there existed some chemical bonds between PU(HTPB) and EP networks. The results of DMS indicated that the IPNs had two Tg which shifted inward in comparison with the Tg's of PU(HTPB) and EP. The Tg1 was only slightly hither than the Tg of soft segments of pure PU(HTPB ), but the Tg2 was remarkably lower than the Tg of EP and lay between the relaxation temperature of the hard segments of PU(HTPB) and the Tg of EP. This demonstrated that the interpenetration of the two networks in this IPNssystem existed only between EP and the hard segments of PU(HTPB). The TEM photographs showed that the morphology of the IPNs varied with the component ratios. With the increase of EP contents, the domain sizes of the IPNs increased gradually and the phase inversion took place between 40% and 60% of EP contents. The mechanical properties of the IPNs materials transformed from reinforced rubbers to toughened plastics with increasing EP contents.