高结晶度iPP/TMC-300复合材料的制备及性能

Synthesis and Properties of High-crystallinity iPP/TMC-300 Composite Materials

摘要:

以全同立构聚丙烯（iPP）和癸二酰二苯甲酰肼（TMC-300）为原料，通过熔融共混技术制备了iPP/TMC-300复合材料，采用DSC、XRD、SEM、POM和力学测试仪器考察了成核剂TMC-300对iPP结晶和熔融行为、晶体结构以及力学性能等方面的影响。结果表明，TMC-300对iPP有显著的成核效果，当TMC-300的质量分数（w）为0.6%时，iPP的结晶温度由纯iPP的117.2℃提高到126.9℃，其成核效率可达到56.3%；在130℃下等温结晶，纯iPP的半结晶时间（t1/2）为4.85 min，当TMC-300的w为0.2%时，t1/2变为0.52 min，减小了近89%，说明添加TMC-300后iPP结晶速率变快。同时，TMC-300的添加并没有改变iPP的晶体结构，而且添加TMC-300的iPP的冲击断裂表面相对纯iPP呈现出了明显的多褶皱韧性断裂形貌特征，其中TMC-300的w为0.2%时，复合材料的断裂伸长率由纯iPP的674.8%提高到了833.2%，缺口冲击强度由32.5 J/m提高到了43.2 J/m，说明添加TMC-300能够有效提高iPP的韧性和塑性。将TMC-300与成核剂TMC-328、HPN-68L对iPP的结晶与力学性能影响进行了对比，TMC-300的w为0.2%时的结晶峰温度为126.2℃，较TMC-328的w为0.2%时的125.2℃略高，其缺口冲击强度（43.2 J/m）较HPN-68L的w为0.2%时的（37.3 J/m）提高了15.8%。

Abstract:

Isotactic polypropylene (iPP) and N, N’-bis(benzoyl) sebacic acid dihydrazide (TMC-300) blends were prepared by means of melt blending. The effects of TMC-300 on the crystallization and melting behaviors, crystal structure and mechanical properties of iPP were studies by DSC, XRD, SEM, POM and mechanical test. The results showed that the addition of TMC-300 had a significant nucleation effect on iPP. When the weight fraction (w) of TMC-300 was 0.6%, the crystallization temperature of iPP increased from 117.2℃ to 126.9℃, and the nucleation efficiency reached up to 56.3%. Pure iPP exhibited a half-time of crystallization (t1/2) of 4.85 min when isothermally crystallized at 130℃, however when w(TMC-300) was 0.2%, the value of t1/2 became 0.52 min and decreased by nearly 89%, indicating that the crystallization rate of iPP increased rapidly after adding TMC-300. Meanwhile, the crystal structure of iPP did not change with the incorporation of TMC-300. Moreover, the impact fracture surface of iPP with addition of TMC-300 showed obvious characteristics of multi fold ductile fracture. When w(TMC-300) was 0.2%, the elongation at break of the composites increased from 674.8% to 833.2% and the notched impact strength increased from 32.5 J/m to 43.2 J/m, which indicated that the addition of TMC-300 could effectively improve the toughness and plasticity of iPP. Finally, the effects of TMC-300 on the crystallization and mechanical properties of iPP were compared with that of nucleating agent TMC-328 and HPN-68L. When w(TMC-300) was 0.2%, the crystallization temperature was 126.2℃, which was slightly higher than that of 0.2% TMC-328 (125.2℃), and the notched impact strength (43.2 J/m) was 15.8% higher than that of 0.2% HPN-68L (37.3 J/m).