Zhou Junhao, Luo Furui, Tang Liming, Guo Zhaoxia
Key Laboratory of Advanced Materials of Ministry of Education of China, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
Molecules. 2024 Dec 12;29(24):5870. doi: 10.3390/molecules29245870.
Waterborne polyurethane, with a mechanical strength comparable to solvent-based types, is eco-friendly and safe, using water as a dispersion medium. Polyacrylate excels in film formation and weather resistance but suffers from "hot stickiness and cold brittleness". Merging polyurethane and polyacrylate creates advanced hybrids, while organosilicon enhances properties but is restricted due to hydrolytic crosslinking. In this paper, a series of polyurethane-polyacrylate hybrid latexes with high organosilicon content were prepared using phase inversion emulsion polymerization technology. Even when the monomer content of 3-(methacryloyloxy)propyltrimethoxysilane (MPS) was increased to 10%, the polymerization process was stable, without the formation of a gel precipitate. The resulting latexes could remain stable for at least 6 months without significant changes in the properties of their films. The effects of MPS content on the mechanical and thermal properties of latex films were systematically researched. The study showed that with an increase in MPS dosage, the hardness and elastic modulus of the latex films increased, while the elongation at break and water absorption decreased, together with the increased glass transition temperature and surface hydrophilicity. This work aims to provide new theoretical guidance for the preparation of silicone-modified hybrid latexes, enabling their safe and stable production and storage.
水性聚氨酯以水作为分散介质，具有与溶剂型聚氨酯相当的机械强度，且环保安全。聚丙烯酸酯在成膜性和耐候性方面表现出色，但存在“热黏冷脆”的问题。将聚氨酯和聚丙烯酸酯结合可制得性能更优的杂化材料，而有机硅虽能改善性能，但因水解交联受到限制。本文采用相转化乳液聚合技术制备了一系列高有机硅含量的聚氨酯 - 聚丙烯酸酯杂化乳液。即便将3 - （甲基丙烯酰氧基）丙基三甲氧基硅烷（MPS）的单体含量提高至10%，聚合过程仍保持稳定，未形成凝胶沉淀。所得乳液至少可稳定保存6个月，其成膜性能无显著变化。系统研究了MPS含量对乳胶膜力学性能和热性能的影响。研究表明，随着MPS用量的增加，乳胶膜的硬度和弹性模量增大，而断裂伸长率和吸水率降低，同时玻璃化转变温度升高，表面亲水性增强。本研究旨在为硅改性杂化乳液的制备提供新的理论指导，实现其安全稳定的生产与储存。
