鞋用水性聚氨酯胶黏剂的制备及表征

通过预聚体分散法,以二羟甲基丙酸(DMPA)、蔗糖(sucrose)为亲水扩链剂和交联剂制备了一种鞋用水性聚氨酯胶黏剂.通过FTIR、DSC、力学性能、固化速度等研究了蔗糖用量对聚氨酯结构与性能的影响.结果表明蔗糖己引入聚氨酯主链.随着蔗糖用量的增加,相同处理温度下聚氨酯胶液的固化速度提高,胶膜的吸水率降低,拉伸强度增大,断裂伸长率减小,粘接试样的T-剥离强度逐渐增大.当蔗糖用量超过5.52 wt%时,合成及乳化过程中体系容易凝聚,且所制得的胶黏剂粘接强度有所下降.总之,通过改变蔗糖用量可以显著改变水性聚氨酯结构与性能.

PREPARATION AND CHARACTERIZATION OF WATERBORNE POLYURETHANE AS SHOE ADHESIVES

A series of waterborne polyurethane(WBPU) adhesives for shoes were synthesized by a prepolymer process using dimethylol propionic acid(DMPA) and sucrose as a hydrophilic agent and a cross-linking agent,respectively.Their structures and thermal behaviors were studied by means of FTIR and DSC.Their water swelling,curing time,mechanical properties,e.g.tensile strength,elongation at break and T-peel strength were measured for all samples with different sucrose contents(0～6.82 wt%).The results showed that the sucrose dispersed well as an incorporated state in the polyurethane phase.The curing time of WBPU samples were decreased with increasing sucrose content at the same treating temperature.The water swelling decreased with increasing sucrose content having an optimum sucrose content at 4.13 wt%,and then it increased slightly with further increase of sucrose content.The tensile strength increased from 8.1 MPa to 22.8 MPa,while the elongation at break decreased from 933.5% to 618.7%.The initial peel strength and final peel strength were significantly increased up to an optimum content of sucrose and then decreased slightly with excess sucrose.In addition,it is noted that polyurethane prepolymers more easily remained at an aggregated state during the process of synthesis,and the adhesive strength of the result products decreased when the sucrose content was more than 5.52 wt%.