| The aims of this research are to discover the synthesis mechanism of high molecular weight methacrylate functionalized POSS and its modification toward PMMA.The synthesis of MA POSS was carried out through hydrolytic condensation of（3-methacryloxypropyl）trimethoxysilane（MPMS）in the presence of formic acid as catalyst,ethanol as a solvent,and TEOS as modifier.The spectra of FTIR and NMR contained residual Si-OH and groups of C=O and Si-O-Si,confirming the structure of methacrylate silsesquioxanes（MSSO）.Mass spectroscopy showed that the formation of MSSOs were increasing continuously through systematic cage arrangement.Due to the high symmetry in T8 cube,most of reaction conditions produced MSSO structure with cage number around eight.The synthesis of high molar mass silsesquioxane was employed at room temperature through the interaction of two POSS molecules and formed two or three times of the initial molecular weight.The incorporation of POSS in PMMA chain was done using bulk polymerization.Based on FTIR,the structure of POSS nanoparticles were successfully incorporated into PMMA matrix with little effect of polymerization reaction.The surface of composites become rougher as the effect of POSS in the PMMA chain.The thermal stability of the composite showed increased degradation temperature due to increasing content of POSS nanoparticles in the PMMA chains.The samples with1wt%and 1.5wt%of POSS increased the first thermal decomposition into 350?C.On the other hand,the sample with 0.5wt%of POSS has slightly different compared to neat PMMA.The glass temperature of composites has increased as the result of cage structure posses by methacrylate POSS in PMMA.The Tg value of neat PMMA was105?C,and PMMA/MSSO-20 1wt%and PMMA/MSSO-8 1wt%were 115?C and113?C,respectively.The tensile strength and flexural strength of composites were different by each type and the content of POSS.Only 0.5wt%of MSSO-8 content successfully increased both tensile and flexural properties of the composite.The decreasing value was influenced by agglomeration and the degree of cross-linking polymer and fillers. |
