热塑性聚氨酯弹性体增韧POM材料的制备及性能

利用同向双螺杆挤出机,通过添加自制马来酸酐接枝乙烯丙烯酸甲酯甲基丙烯酸缩水甘油酯无规三元共聚物相容剂制备热塑性聚氨酯(PUR-T)弹性体增韧聚甲醛(POM)合金材料,采用差示扫描量热对比研究了加入PUR-T前后材料结晶和熔融温度的差异,并考察了PUR-T用量及相同PUR-T用量下螺杆组合(即螺纹块剪切强弱)对材料力学性能和摩擦磨损性能的影响。结果表明,PUR-T的加入降低了合金的结晶和熔融峰温度;随着PUR-T用量的增加,材料断裂伸长率、缺口冲击强度呈增大趋势,密度、拉伸强度、弯曲强度和弯曲弹性模量呈下降趋势,摩擦系数和磨损量呈先下降后上升趋势,当PUR-T用量为10份时,合金综合力学性能和摩擦磨损性能较优;螺纹块剪切对POM/PUR-T合金材料力学性能影响较大,螺纹块剪切越强,力学性能劣化越明显,螺纹块剪切对合金材料的摩擦磨损性能影响不大。

Preparation and Properties of POM Toughened by Thermoplastic Polyurethane Elastomer

The thermoplastic polyurethane(PUR-T)elastomer toughened polyoxymethylene(POM)alloy was prepared by corotating twin screw extruder with self-made maleic anhydride grafted ethylene-methyl acrylate-glycidyl methacrylate random terpolymer as compatibilizer.The difference of crystallization and melting temperature of POM and POM/PUR-T was compared by DSC.The effects of PUR-T content and screw combination(shear strength of screw block)under the same PUR-T content on the mechanical,friction and wear properties of the alloy were investigated.The results show that,the addition of PUR-T reduces the crystallization and melting peak temperature of the alloy.With the increase of PUR-T content,the elongation at break and notched impact strength of the alloy increase,while the density,tensile strength,bending strength and bending modulus decrease,the friction coefficient and wear loss first decrease and then increase.When the content of PUR-T is 10 phr,the comprehensive mechanical,friction and wear properties of the alloy are better.The shear strength of screw block has great influence on the mechanical properties of POM/PUR-T alloy,the stronger the shear strength of screw block is,the more obvious the deterioration of mechanical properties is,but the shear strength of screw block has little effects on the friction and wear properties of the alloy.