Abstract In this study, the effects of polybenzimidazole (PBI) and polyacrylic acid (PAA) modified carbon black (MCB) on the anti-UV-weathering and thermal properties of PVC composites were investigated. The optimal mass ratios of PBI and MCB to PVC are 0.1 wt% and 0.2 wt%, respectively, and the resultant 1PBI/2MCB/PVC composite membrane with a thickness of about 60 μm can block over 99% of UV light below 380 nm. The UV absorption mechanism was investigated by the optional band gap (Eg) and the fluorescence spectroscopy. The incorporation of PBI and MCB results in a decrease in Eg, from 4.96 eV for PVC membrane to 2.90 eV for 1PBI/2MCB/PVC composite membrane, and MCB can quench the fluorescence of PBI by photon-induced electron transfer to further protect PVC. The results of accelerated UV-weathering experiment indicate that the incorporation of PBI and MCB can improve the anti-UV-weathering property of PVC. The thermal degradation behaviors of PVC and its composite membranes in air and N2 atmosphere were also investigated. The highest char residue (13.7 wt%) is obtained in 1PBI/2MCB/PVC composite membrane at 800 °C in N2 atmosphere, with an increase of 73.4% compared with that of PVC membrane, which may be because PBI and MCB can synergistically accelerate the carbonization of PVC molecules to rapidly form stable char residue.

中文翻译：

---

聚苯并咪唑和聚丙烯酸改性炭黑对聚氯乙烯复合材料抗紫外线老化和热性能的影响

摘要 本研究研究了聚苯并咪唑（PBI）和聚丙烯酸（PAA）改性炭黑（MCB）对PVC复合材料抗紫外线老化和热性能的影响。PBI和MCB与PVC的最佳质量比分别为0.1 wt%和0.2 wt%，所得1PBI/2MCB/PVC复合膜厚度约60 μm，可阻挡99%以上380 nm以下的紫外光。通过可选的带隙 (Eg) 和荧光光谱研究了紫外吸收机制。PBI 和 MCB 的掺入导致 Eg 降低，从 PVC 膜的 4.96 eV 到 1PBI/2MCB/PVC 复合膜的 2.90 eV，并且 MCB 可以通过光子诱导的电子转移淬灭 PBI 的荧光，进一步保护 PVC。加速UV老化实验结果表明，PBI和MCB的掺入可以提高PVC的抗UV老化性能。还研究了 PVC 及其复合膜在空气和 N2 气氛中的热降解行为。1PBI/2MCB/PVC 复合膜在 N2 气氛中 800 °C 的炭残留量最高（13.7 wt%），与 PVC 膜相比增加了 73.4%，这可能是因为 PBI 和 MCB 可以协同加速PVC 分子碳化，迅速形成稳定的炭渣。