Effect of Chain Transfer Agent on property of Cross-linked Polymethacrylate Sheets

• Main Authors: Xin-Yuan Huang, 黃信淵
• Other Authors: Fu-San Yen
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/45703743339765097417

碩士 === 國立高雄應用科技大學 === 化學工程與材料工程系 === 99 === Semi-interpenetrating network PMMA (xPMMA) was prepared by using the MMA as the basic monomer and the dimethacrylate of CH2=C(CH3)-COO-(CH2CH2-O)n-OC-(CH3)C=CH2 with different n as the cross-linking agent (XLA) through the free radical polymerization. Concentration effect of both the chain transfer agent (CTA) and XLA on the thermal and mechanical properties of the xPMMAs were investigated. An Instron was used to demonstrate the tension strength and the elongation degree of the xPMMAs. Solvent swelling test was applied to compare the swelling ability and then the cross-linking degree. The TGA and DSC were used to describe the thermal stability and thermal transition temperature under heating. Finally, a lab-made vacuum forming mould was used to distinguish the thermal forming facileness of processing the xPMMAs. The TGA experimental results showed that the thermal stability of the xPMMAs is higher than the non-cross-linked, and increases with the CTA concentration while decreases with the n of the -(CH2CH2-O)n- segment. While, the DSC results showed no significant effect of the low XLA concentration on the Tg of xPMMAs. From the Instron experiments, it appeared that the mechanical characteristic of the xPMMAs is very similar with the non-cross-linked at room temperature. At elevated temperature, it showed that the tensile strength is related with both the -(CH2CH2-O)n- segment length and the CTA concentration. At a temperature (80 oC) lower than the Tg of the xPMMA, the tensile strength increases with the CTA dosage, but decreases with the -(CH2CH2-O)n- segment length. While at a temperature (160 oC) farther higher than the Tg of the xPMMA, the tensile strength decreases with both the CTA dosage and the -(CH2CH2-O)n- segment length. The thermal forming molding tests showed that xPMMAs have higher thermal forming ability than the non-cross-linked. The thermal forming depth and shape of the xPMMAs are proportional with both the CTA dosage and the -(CH2CH2-O)n- segment length.