Umemoto K, Kurata S
Department of Dental Materials, Kanagawa Dental College, Japan.
Dent Mater J. 1997 Jun;16(1):21-30. doi: 10.4012/dmj.16.21.
To improve the water sorption of poly(methyl methacrylate), new hydrophobic monomers, such as norbonyl and phenyl methacrylate, were studied to determine the resin with lower water sorption with no decrease in mechanical property. Water sorption of the copolymers of the hydrophobic monomers and MMA decreased with the increase in the concentration of the monomers. Compressive and bending strength of the copolymers were higher than that of PMMA, and the elastic modulus in bending was the same as that of PMMA. In addition, the transverse-deflection values satisfied ADA specifications. Dynamic mechanical thermal analysis of the copolymers showed a similar tendency to that of PMMA in spite of the introduction of bulky groups, such as norbonyl and phenyl, in the polymer molecule. The polymerization shrinkage in volume was in the following order: norbonyl < phenyl < methyl methacrylate.
为提高聚甲基丙烯酸甲酯的吸水性，研究了新型疏水性单体，如降冰片基甲基丙烯酸酯和苯基甲基丙烯酸酯，以确定在不降低机械性能的情况下具有较低吸水性的树脂。疏水性单体与甲基丙烯酸甲酯的共聚物的吸水性随单体浓度的增加而降低。共聚物的压缩强度和弯曲强度高于聚甲基丙烯酸甲酯，弯曲弹性模量与聚甲基丙烯酸甲酯相同。此外，横向挠度值符合美国牙科协会规范。尽管聚合物分子中引入了庞大的基团，如降冰片基和苯基，但共聚物的动态力学热分析显示出与聚甲基丙烯酸甲酯相似的趋势。体积聚合收缩率顺序如下：降冰片基＜苯基＜甲基丙烯酸甲酯。
