The Preparation And Properties Research On Anti-ultraviolet PVA Composite Films

In recent years, how to prevent ultraviolet radiation has aroused the attention of people, and researches on adding ultraviolet absorbers to improve clothing, packing are increasing. Adopting green environmental protection and biodegradable materials become the important direction of packing. So this study used PVA as the main raw material, adding inorganic or organic ultraviolet absorbers, and other additive, through a solution casting method for producing the anti-ultraviolet and good Transparency PVA composite films. The main conclusions are as follows:(1) This work adopted surfactant agents (Triethanolamine, Sodium dodecyl sulfate, Polyethylene pyrrole) and coupling agents (KH560, (KH550, KH570) to modify the inorganic ultraviolet absorbers (nano-TiO₂), and researched the settlement and dispersing capability in the water. The method of FTIR, settlement method, Thermogravimetry(TG) analysis, XRD analysis were used to characterize the effect of surface modification and dispersivity of nano powder. The results indicated that: using Triethanolamine with other surfactants improved the dispersion of nano-TiO₂ in the water. The dispersivity of coupling agent modified nano powders was better than using surfactant modified nano-powders and the dispersivity of nano-TiO₂ modificated by KH550 was the best.(2)The crystallization behavior, mechanical properties, rheological properties, barrier performance, and the influence of water resistance of the film with the modified or non-modified nano-TiO₂ were tested. The result shown that after adding the nano materials in the PVA, the hydrogen bonding interaction was formed between the nano-particles and molecular chain, which improved the viscosity and crystallinity of the composite glue. The Tensile strength of the composite film was increased, but Elongation decreased largely. The water resistance of the composite films was enhanced compared to the pure film. The Moisture permeability coefficient and Oxygen transmission coefficient decreased, and barrier property improved. (3)This work studied the influence of composite film ultraviolet transmittance and transparency with different ultraviolet absorbers, different contents, different surface modification methods of inorganic ultraviole absorbers, then analysised the resistance mechanism of composite films further.The UV transmittance of the composite films with nano-TiO₂ was lower than adding UV-284 and nano-ZnO. Along with the increase of the content of ultraviolet absorber, the UV transmittance of the compound films reduced gradually. After adding the inorganic UV absorbers, the Transmittance of the compound films declined, but Haze degree increased. Add the nano-TiO₂ modified by coupling agent, the Transmittance of the composite film was better than adding surfactants modifided nano-TiO₂, but Haze was substantially higher than the latter.