摘要
通过在软段和硬段中分别引入带有对称和非对称侧甲基结构的PNA、1,2-PG,采用WAXD、SEM、FT-IR、DSC等方法,考察了软硬段结构及硬段含量的改变对聚氨酯胶粘剂软硬段结晶行为、微相分离结构,以及对粘接性能、力学性能的影响。结果表明,PNA的引入降低了聚氨酯胶粘剂的软硬段结晶能力,提高了微相分离程度。引入1,2-PG后硬段结晶能力及相分离程度下降,软段结晶性提高;相应的拉伸强度随1,2-PG用量的增加而降低,粘接强度从16.8 N/cm增加到18.1 N/cm;随着硬段含量从23%增加31%时,胶粘剂的拉伸强度从25.6 MPa增加到37.1 MPa,但弹性下降。
A series of polyurethane adhesives were prepared by using MDI-BDO as the hard-segment and PBA as the soft-segment. In order to control the crystallinity of the hard and soft segments, 1,2-PG and PNA, which contain dissymmetrical and symmetrical side methyl groups respectively, were incorporated into the hard-segment and the soft-segment respectively. The influences of the changes of the soft-segment and the hard-segment structures and their contents on the crystallinity, micro-phase separation, mechanical properties and adhesive strength were studied by DSC, WAXD, and SEM. The results show that the introduction of PNA reduced the crystallinity of the soft- and the hard-segment simultaneously, and increased the micro-phase sepa- ration. The crystallinity and micro-phase separation of the hard-segments decreased upon the introduction of 1,2-PG, and the tensile strength decreased with the increased content of 1,2-PG; however, the adhesive strength increased from 16.8 N/cm to 18. 1 N/cm. When the hard-segment content increased from 23% to 31% , the tensile strength of polyurethane adhesive was enhanced from 25.6 MPa to 37. 1 MPa, but the elasticity declined.
出处
《应用化学》
CAS
CSCD
北大核心
2005年第10期1141-1144,共4页
Chinese Journal of Applied Chemistry
关键词
聚氨酯胶粘剂
结晶
微相分离
软段
硬段
polyurethane adhesive,crystallinity,micro-phase separation,soft-segment,hard-segment
