Effect of high-pressure polymerization on mechanical properties of PMMA denture base resin
Effect of high-pressure polymerization on mechanical properties of PMMA denture base resin
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DOI：
10.1016/j.jmbbm.2012.12.011
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发表时间：
2013-04-01
影响因子：
3.9
通讯作者：
Igarashi, Yoshimasa
中科院分区：
文献类型：
--
作者：
Murakami, Natsuko;Wakabayashi, Noriyuki;Igarashi, Yoshimasa
本研究的目的是评估高压聚合对义齿基托树脂力学性能的影响。将热固化义齿基托树脂和实验PMMA在500 MPa的压力下通过等静压加压机在70 ℃下聚合24 h，以制备尺寸为30 mm × 2 mm × 2 mm的矩形试样。每个试样在三点弯曲试验中挠曲，直到发生断裂或样品被加载至挠曲达8 mm。采用高速液相色谱系统对无填料的PMMA的分子量进行了分析。在高压下的试样中显示出增加的延展性而不断裂，而大多数对照试样（环境压力）断裂。在高压下聚合的PMMA样品的平均韧性显著高于在环境压力下聚合的相同材料（p < 0.01）。与对照组相比，高压组的义齿树脂和PMMA的平均0.2%屈服应力、弯曲强度和弹性模量显著降低（p < 0.01）。高压样品中存在一定量的比对照样品中存在的更高分子量的聚合物。在高压下聚合的PMMA中显示出的韧性增加可能归因于压力产生的更高的分子量。结果表明，高压聚合的潜在应用的PMMA基义齿树脂的开发具有改善的抗断裂性能。(C)2013爱思唯尔有限公司保留所有权利。
The aim of this study was to assess the effect of high-pressure polymerization on mechanical properties of denture base resin. A heat-curing denture base resin and an experimental PMMA were polymerized under 500 MPa of pressure by means of an isostatic pressurization machine at 70 degrees C for 24 h to make rectangular specimens whose dimensions were 30 mm x 2 mm x 2 mm. Each specimen was deflected on a three-point flexural test until either fracture occurred or the sample was loaded up to 8 mm in deflection. The molecular weight of the PMMA without filler was analyzed using the high-speed liquid chromatography system. Increased ductility without fracture was shown in the specimens subjected to high pressure, while most of the control specimens (ambient pressure) fractured. The mean toughness of the PMMA specimens polymerized under the high pressure was significantly higher than the same material polymerized under ambient pressure (p < 0.01). The high pressure groups of the denture resin and the PMMA revealed a significantly lower mean 0.2% yield stress, flexural strength, and elastic modulus than control groups (p < 0.01). There were certain amounts of higher molecular weight polymers in the high pressure specimens than were present in the controls. The increased toughness shown in the PMMA polymerized under the high pressure was presumably attributed to the higher molecular weight produced by the pressure. The result suggests a potential application of the high-pressure polymerization to the development of PMMA-based denture resin with improved fracture resistance. (C) 2013 Elsevier Ltd. All rights reserved.