Preparation And Application In PVC Resin Of Polyacrylate/silica Composite Material

Polyacrylate (ACR) have much more advantages when it was used in the thermoplastic resin (such as PVC), improving impact strength, increasing plasticizing property, promoting the strengthening and toughening of resin and so on. But it was usually at the expense of precious materials such as rigid, heat resistance, dimensional stability and processable properties. In addition, the cost of polyacrylate was expensive. With the emergence of nanotechnology, because the nanoparticle itself is surface effect and quantum effect features, it can not only improve the material tenacity, at the same time material rigid and strength also be improved. Therefore, nanotechnology was an innovative ways for PVC plastic modification. In this dissertation, silica sol was modified by silane coupling agent before it was used as inorganic nano-particle, Polyacrylate/SiO2 sol complex emulsion was synthesized by emulsion polymerization and its application in the PVC resin was researched in the next work.The main contents and related achievements are as follows:The silica sol was modified by different chain lengths and functional groups of silane coupling agents, then it was characterized by FT-IR, DLS, TG etc. The experiments showed that silane coupling agent KH-560 was successfully grafted onto the surface of silica sol, improving the lipophilicity with the ACR as some organic groups were introduced.The size and its distribution of composite latex particle was tested by Dynamic Light Scattering. The composition changes of ACR/SiO2 were inspected by IR, the thermal decomposition performance was measured by TG, the glass-transition temperature was measured by DSC and the structure was observed by TEM. The surface morphology of ACR/SiO2 composite particles with different content of SiO2 were observed by SEM at last. The experiments showed that the size and its distribution of ACR/SiO2 composite latex particle can be adjusted by using seeded emulsion polymerization; FT-IR, TG characterization showed that the modified nano-SiO2 had a degree of compound with ACR latex; TEM, SEM results further proved the interface relationship. It was found that the silica sol was existed as SiO2 and uniformly adsorbed on the surface of ACR latex particles; DSC analysis showed that the composite particles ACR/SiO2 had a glass transition temperature (Tg) more than ACR.Effects of ACR/SiO2 on the plasticizing properties and mechanical properties of PVC were investigated. The results show that ACR/SiO2 composite materials could promote the plasticization of PVC, shorten fusion time, increase plasticizing property, and have no obvious bad effects; composite particles could be better dispersed in the PVC matrix and improve the impact strength of PVC obviously. The notched impact strength of PVC and ACR/SiO2 blends could be increased most obviously, when the weight ratio of ACR/SiO2 and PVC is 6/100, SiO2 and ACR is 15/100.