关键词: 聚乙烯醇缩丁醛, 马来酸酐, 改性, 聚合性能, 蓝光固化

Abstract: PVB is a polymer material that contains hydroxyl, ester, and acetal groups in macromolecules. The presence of hydroxyl groups makes PVB resin soluble in polar or strongly polar solvents, and can undergo cross-linking reactions with phenolic, urea formaldehyde, epoxy resins, etc., providing strong tear resistance and good bonding performance. The six membered ring structure of the acetal group affects the hardness, toughness, and crystallinity of PVB molecular chains. In addition, PVB resin also has excellent light resistance, water resistance, film forming ability, and impact resistance. The unique structural characteristics enable PVB to be applied in fields such as ceramic printing paper, adhesives, coatings, aluminum foil paper, artificial sponges, etc. However, the most important application field is the production of automotive safety glass sandwich membrane materials. In the event of glass being impacted and broken, the PVB sandwich acts as an energy absorber. This PVB is a high viscosity resin with a molecular weight between 100000 and 250000. Due to the rapid development of the automotive and construction industries, the demand for safety glass has been increasing year by year, which has also led to the accumulation of discarded PVB. Improper treatment can cause environmental pollution and waste of resources. At the same time, due to the pollution of the environment and the harm to health caused by organic solvents, non-toxic, harmless, and environmentally friendly water is used as a solvent to replace the organic solvent system in its application process. In its preparation process, low-cost modifiers and reaction systems should be used as much as possible to reduce reaction steps, increase product yield, and prepare low-cost and high-performance PVB modified products. This has important research significance and can achieve the green application of PVB. Due to the poor hydrophilicity of PVB resin, it can be improved through grafting modification. Maleic anhydride has excellent hydrophilicity and contains carbon carbon double bonds within the molecule, making it suitable for use in the field of blue light curing. Its reaction with PVB is mainly realized by esterification with hydroxyl in PVB after C−O−C bond breaks. Blue light curing technology is that excited state molecules absorb photothermal energy and then undergo chemical reaction to realize the curing of polymerization system. This technology is efficient, low consumption and environmental protection. In order to recover and reuse rPVB, PVB-M was obtained by modifying and grafting pure PVB with maleic anhydride and introducing double bonds. The coated fabric was prepared by UV curing coating technology. The structural characterization of PVB-M showed that the grafting reaction was successful. The polymerization performance of PVB modified by maleic anhydride was the best when the temperature was 70 ℃, the time was 6 h, the amount of maleic anhydride was 3 g, the mass fraction of photoinitiator system was 1%, and the mass ratio of PVB-M to HEA was 1:2. The polymerization performance and membrane mechanical properties of modified PVB were improved. The addition of kaolin promotes the mechanical properties of the light cured film, and the surface structure of the coating slurry applied to the fabric is uniform. On this basis, rPVB was modified to prepare rPVB-M, and the feasibility of its application on coated fabrics was explored. The results showed that there was no significant difference in their performance compared to PVB-M coated fabrics. Therefore, rPVB can be applied in the field of textile coating for recycling and reuse.

Key words: polyvinyl butyral, Maleic anhydride, Modification, Polymerization performance, Blue light curing