阻燃热塑性弹性体加工过程中的性能变化

Performance Variation of Thermal Plastic Elastomer Flame-Retardant Formulation During Internal Mixing

通过密炼法加工含有聚酯/甲基次磷酸铝/三聚氰胺聚磷酸盐(TPEE/AMP/MPP)的热塑性弹性体,在保持体系组成恒定的条件下,考察了加工温度和加工次数对热塑性弹性体系阻燃性能、力学性能、热稳定性和结晶性的影响。结果表明:当AMP/MPP在体系中质量为22%,AMP/MPP质量比为3∶1时,225℃密炼20 min,材料垂直燃烧测试可达到UL94 V-0级;提高加工温度和密炼次数,材料的断裂伸长率增加,在225℃条件下密炼3次,每次20 min,材料的断裂伸长率可达到45. 45%。XRD以及差式扫描量热分析(DSC)结果表明,加工方式的改变并未改变材料的结晶方式,但降低了TPEE的结晶度和晶体的规整性。此外,增加加工次数与温度能提高材料的热稳定性和氧指数。

Thermoplastic elastomer composed of polyester, methyl phosphite, melamine pyrophosphate （TPEE/AMP/ MPP） flame-retardant were processed by internal mixing. The influence of mixture temperature and frequency on the performanee including flame retardancy,mechanical properties,thermostablity and crystalliuity of formulations were investigated when the formulation of the system was kept constant. The results showed that when the total dosage of the AMP and MPP was kept at 22% , and the weight ratio of AMP and MPP was 3： 1, the best flame retardancy was achieved and the vertical combustion test of the samples passed the UL94 V-0 ratio after formulation was milled at 225 ℃ for 20 min. The elongation of the sample was improved with the milling cycles increasing. The elongation of 45.45% was obtained after formulation was milled 3 times at 225 ℃ with 20 min per time. The results from XRD and DSC showed that milling temperature and times had no influence on the crystallization behavior of the TPEE, but the degree of the crystallization and regularity of the crystal changed with the processing mode. In addition, the thermal stability and the limited oxygen index of the sample were improved by increasing processing cycles.