纳米SiO_2/聚甲基丙烯酸甲酯透明复合材料的制备及透光率

首先利用γ-甲基丙烯酰氧基丙基三甲氧基硅烷(MPS)对纳米SiO_2进行表面改性(SiO_2-MPS),再通过原位聚合法在SiO_2-MPS表面接枝聚甲基丙烯酸甲酯(PMMA)。采用熔融共混法将未改性和改性SiO_2与PMMA共混制成预分散母料,再分别与PMMA熔融共混制备纳米SiO_2/PMMA透明复合材料。用FTIR、TG和SEM对不同表面处理的纳米SiO_2和纳米SiO_2/PMMA复合材料的结构进行表征,并对其冲击强度、接触角和透光率进行表征。结果表明:SiO_2-MPS/PMMA复合材料中纳米SiO_2与MPS、MPS与PMMA间形成化学键,接枝率分别达到10.01%和22.95%,SiO_2-MPS-PMMA在PMMA中分散性最好,团聚现象明显减少,与纯PMMA相比,SiO_2/PMMA、SiO_2-MPS/PMMA和SiO_2-MPS-PMMA/PMMA复合材料的冲击强度、与水接触角均略有提升,透光率达到90%左右,最高可达94.2%。

Preparation and transmittance of nano-SiO2/PMMA transparent composites

The surface of SiO2 nano-particles was modified by γ-(trimethoxysily) propyl methacrylate (MPS) to prepare SiO2-MPS, and polymethylmethacrylate (PMMA) was grafted to the SiO2-MPS to prepare SiO2-MPS-PMMA via in situ polymerization.The nano-SiO2/PMMA transparent composites were prepared via melt blending method with PMMA and the pre-dispersed masterbatch which were prepared via melt blending method with PMMA and SiO2-PMS, SiO2-MPS-PMMA, respectively.Nano-SiO2 treated by MPS and PMMA were characterized and analyzed by FTIR and TG, and the structure of the nano-SiO2/PMMA composites was analyzed by SEM.The impact strength, contact angle and transmittance of the nano-SiO2/PMMA composites were also characterized.The results show that the chemical bonds are formed between nano-SiO2 and MPS, MPS and PMMA in SiO2-MPS/PMMA composites.The graft rate of MPS on the surface of nano-SiO2is 10.01%, while that of PMMA is 22.95%.In contrast, SiO2-MPS-PMMA has a better dispersion and lower aggregation in the PMMA.Compared to the pure PMMA, the impact strength and contact angle of the composites prepared by unmodified nano-SiO2 and organic modified nano-SiO2are slightly improved, and the transmittance reaches about 90%, up to 94.2%.