PVC硬脂酸轻稀土热稳定剂的复配与应用研究

Synergism and Application of Light Rare Earth Stearate as Thermal Stabilizer for PVC

为了进一步研发性价比高且＂无铅化＂的稀土复合热稳定剂,研究了系列硬脂酸轻稀土盐（镧/铈/镨/钕/钐/铕/混合）与其他常用PVC热稳定（助）剂的复配效果。通过刚果红试纸法、红外光谱分析（FT-IR）、转矩流变仪等探究了复合热稳定剂对PVC性能的影响。结果表明：复合热稳定剂配方为硬脂酸轻稀土盐0.7~1.0份、硬脂酸锌0.8~0.9份、β-二酮0.3~0.6份和季戊四醇0.8~0.9份。将3份复合热稳定剂添加到100份PVC树脂中,静态及动态热稳定时间延长至100和35 min左右;动态热稳定性能和力学性能优于市售钙锌热稳定剂,与市售铅盐较接近。红外光谱分析表明复合热稳定剂可在加热初期减缓PVC氧化降解,较好地抑制初期着色,对PVC性能影响顺序为：镧组〉钕组〉混合组〉铈组〉镨组〉钐组〉铕组。

In order to further develop the compound rare earth thermal stabilizers with high performance price ratio and ＂lead-free＂,the compound effect of serial light rare earth（ La / Ce / Pr / Nd / Sm / Eu / MER） stearates were investigated with other commonly-used thermal stabilizers,respectively. The influence of compound thermal stabilizers on PVC was studied by Congo red testing method,FT-IR and torque rheometer. The result showed that the compound formula was light rare earth stearate 0. 7 ~ 1. 0 portion,zinc stearate 0. 8 ~ 0. 9 portion,β-diketone 0. 3 ~0. 6 portion and pentaerythritol 0. 8 ~ 0. 9 portion. The static and dynamic thermal stability time could reach about100 min and 35 min when 3 portion compound thermal stabilizer was added in 100 portion PVC. The dynamic thermal stability performance and mechanical property were better than those of commercial Ca / Zn thermal stabilizers,similar to those of commercial lead salt. FT-IR spectra indicated that the compound thermal stabilizers could relieve the oxidation degradation of PVC and inhibit the sample color at the beginning of heating. The order of the performance effect on PVC was as follows： La G 〉 Nd G 〉 MREG 〉 Ce G 〉 Pr G 〉 Sm G 〉 Eu G.