State Key Laboratory of Chemical Resource Engineering, and Beijing Engineering Center for Hierarchical Catalysts, Beijing University of Chemical Technology, Beijing 100029, P.R. China.
Dalton Trans. 2019 Feb 19;48(8):2750-2759. doi: 10.1039/c9dt00111e.
Two kinds of UV absorbers 2-hydroxy-4-methoxy-benzophenone-5-sulphonic acid (HMBA) and cinnamic acid (CA) were successfully co-intercalated into the interlayer of Mg2ZnAl layered double hydroxides (LDH) by a modified coprecipitation method to prepare novel UV-shielding material HMBA-CA-LDH for improving the anti-photoaging capability of polypropylene (PP). The characterization results reveal the presence of host-guest interactions between the LDH host layers and HMBA/CA guest anions as well as guest-guest interactions between guest anions in HMBA-CA-LDH, and the HMBA-CA-LDH has much stronger UV absorption capability than the HMBA intercalated LDH (HMBA-LDH) in the whole UV band and a much broader UV absorption band than the CA intercalated LDH (CA-LDH). A series of LDH/PP composites with evenly dispersed LDH nanosheets were prepared by incorporating the prepared LDHs into the matrix of PP via the solvent casting method. As expected, LDH/PP composites show higher thermal stability and better anti-photoaging ability than pristine PP. Interestingly, HMBA-CA-LDH/PP shows better anti-photoaging performance in comparison with HMBA-LDH/PP and CA-LDH/PP because of its better UV-shielding ability arising from the synergistic UV-shielding effects of both HMBA and CA, and the HMBA-CA-LDH can reduce the photodegradation of PP by about 85%. Hence, the prepared novel HMBA-CA-LDH has potential application in the field of PP as an efficient and promising UV-shielding material.
两种紫外吸收剂 2-羟基-4-甲氧基二苯甲酮-5-磺酸（HMBA）和肉桂酸（CA）通过改进的共沉淀法成功地共插层到 Mg2ZnAl 层状双氢氧化物（LDH）的层间，制备了新型的紫外屏蔽材料 HMBA-CA-LDH，以提高聚丙烯（PP）的抗光老化性能。表征结果表明，在 LDH 主体层与 HMBA/CA 客体阴离子之间存在主客体相互作用，以及在 HMBA-CA-LDH 中的客体阴离子之间存在客体-客体相互作用，并且 HMBA-CA-LDH 在整个紫外波段比 HMBA 插层 LDH（HMBA-LDH）具有更强的紫外吸收能力，并且比 CA 插层 LDH（CA-LDH）具有更宽的紫外吸收带。通过将制备的 LDH 通过溶剂浇铸法掺入 PP 基质中，制备了一系列 LDH/PP 复合材料，其中 LDH 纳米片均匀分散。不出所料，LDH/PP 复合材料比原 PP 具有更高的热稳定性和更好的抗光老化能力。有趣的是，HMBA-CA-LDH/PP 比 HMBA-LDH/PP 和 CA-LDH/PP 具有更好的抗光老化性能，因为它具有更好的紫外屏蔽能力，这是由于 HMBA 和 CA 的协同紫外屏蔽效应，并且 HMBA-CA-LDH 可以将 PP 的光降解率降低约 85%。因此，所制备的新型 HMBA-CA-LDH 具有在 PP 领域作为有效和有前途的紫外屏蔽材料的潜在应用。
