端羟基丁二烯型聚氨酯/聚苯乙烯互穿聚合物网络的研究

A STUDY ON INTERPENETRATING POLYMER NETWORK OF POLYBUTADIENE BASED POLYURETHANE/POLYSTYRENE

研究了同步法合成的端羟基聚丁二烯型聚氨酯/聚苯乙烯互穿聚合物网络〔PU(HTPB)/PS_t-IPN〕的形态结构、热转变行为和力学性能。电镜结果表明:该类 IPN 形成既二相分离又各自连续的相结构,当 PU(HTPB)/PS_t 组成比为25/75时,体系发生相转变;组成比为50/50左右时,形成的聚苯乙烯分散相区域尺寸较小。增加每一相的交联程度,均可提高二相的互穿能力,所有 IPN 都呈现出独特的细胞状结构形态,文中根据聚氨酯首先形成的事实,提出了该结构的形成机理。T_(?)研究结果表明:玻璃化转变温度的移动将受到 IPN 自身诸因素的制约。力学性能结果表明:随 IPN 中 PU(HTPB)含量增加,材料的刚性下降,而断裂伸长则出现由增加到下降的过程,在组成比为60/40左右时,达最大值。

Morphology,thermal transition behaviour and mechanical property ofinterpenetrating polymer network of polybutadiene based polyurethane/polysty-rene were studied.The result of TEM showed that the resulting PU(HTPB)/PSt—IPN formed the phase structure which was two phase separationas well as continuous itself.The phase inversion occurred in the concentrationof 25%PU,and the size of phase regions formed was smaller in the concent-ration about 50%PU for PU(HTPB)/PSt-IPN.Increasing DVB content or pro-portion of NCO to OH enhaneed interpenetration of two components.All ofIPN samples exhibited special cellular shape morphology structure,according tothe fact that the PU was formed first,the formation mechanism of the struc-ture was proposed in the paper.DSC showed that the shift of T_g was controlled by the internal elements in the system.Mechanical properties exhibitedthat increasing PU(HTPB) content depressed the strength of the material,butthe elongation at break increased first,then decreased,and reached the maximumin 60%PU.