木糖醇类成核剂与山梨醇类成核剂对聚丙烯改性性能的比较

Comparison of Properties of Polypropylene Modified by Xylitol Nucleating Agent and Sorbitol Nucleating Agent

采用木糖醇和3,4-二甲基苯甲醛为原料合成木糖醇类成核剂(DMDBX),并对所合成产品进行元素分析、红外光谱、核磁共振氢谱和碳谱表征及差热分析。结果表明,与结构上相似的Millad 3988和Millad NX8000对聚丙烯进行成核改性相比,成核剂添加量为0.2%时,空白聚丙烯和聚丙烯/DMDBX的雾度值分别为36.3%和17.6%,拉伸强度分别为34.90 MPa和36.90 MPa,维卡软化点分别为158.6℃和157.0℃。

1,3-2,4-Di（3,4-dimethylbenzylidene） xylitol （DMDBX） was synthesized by using xylitol and （3,4-dimethyl） benzaldehyde as raw materials. The resulting product was characterized by element analysis, Fouriertransform infrared spectroscopy, 1H-NMR, 13C-NMR and differential scanning calorimetry. The haze of PP decreased to 17.6 % with the addition of DMDBX as a nucleation agent, while the haze of pure PP reached 36.3 %. However, its impact strength and tensile strength were improved to 5.083 MPa and 36.90 MPa compared with 4.527 MPa and 34.90 MPa of pure PP, respectively. Moreover, its Vicat softening point decreased from 158.6 ℃ to 157.0 ℃, respectively. It is evident that DMDBX can improve the optical property of PP significantly, slightly enhance mechanical properties, but has little on thermal stability.