Research On Modification Of Polyvinyl Chloride （PVC） With Nano-TiO₂Through In-Situ Polymerization

Nnano-TiO₂was added into PVC throuth in situ polymerization forthe modification of PVC. The mechanical properties and Vicat softeningtemperature got the main attention. Considering the interforce betweenPVC and Nano-TiO₂, silane coupling agent was used to coat Nnano-TiO₂.The coating solvent was considered as a influencing factor to the effect ofcoating and the properties of the PVC. Mmain work is as follows:（1） Nano-TiO₂was coated by silane coupling agent in differentsolvent. The relationship between scatterering ways, solvent, amount ofcoupleing agent, reaction time and the effect of coating were studied.Ultrasound with mechanical agitation was found a effective way. TiO₂coated in different solvent would be differern in congtact angle withwater, particle size distribution and the amount of coupling agent graftedonto the Nano-TiO₂. In70℃in toluene, Nano-TiO₂would be wellcoated in1h, and the amount of coupling agent grafted was3%⁶%to thenano TiO₂quality of nano TiO₂.（2） Nano-TiO₂was added into the PVC through insitupolymerization, it can be reserved that Nano-TiO₂was well scattered from the TEM graph.Infrared spectrum （TR） and thermogravimetric analysis （TG） verify thatthere are bonds between PVC and coated nano-TiO₂, the PVC guraftedonto nano-TiO₂was about36wt%to the quality of TiO₂.（3）Combined action of CaCO₃and nano-TiO₂showed to be asynergy. The tensile strength, elongation at break and vicat softeningtemperature were all increased in the PVC，after CaCO₃was added. Thevicat softening temperature curve showed a peak when TiO₂was aeddedonly0.1%. the vicat softening temperature got to88.5℃from84.5℃.（4） Nano-TiO₂coated in different solvent was added into PVCthrough insitu polymerization. They showed different in the scatteringsituation. Nano-TiO₂coated in toluene showed better in raising the vicatsoftening temperature. It rised again when CaCO₃was added into thePVC. When the nano-TiO₂was added0.1wt%of PVC, CaCO₃10wt%ofPVC, the vicat softening temperature got to91℃from84.5℃.（5） Study on the modified PVC with the nano-TiO₂coated in tolueneshowed maybe there is ordered structure in PVC.