论文部分内容阅读
聚甲基丙烯酸甲酯(PMMA)是口腔修复常用的一种树脂。它的聚合是一种需要引发剂(过氧化苯酰)活化的加成反应。使过氧化苯酰产生游离基,通过打开PMMA的双价键引发聚合链的反应。传统的固化方法有两种。一种是在热汽炉或水中,在恒温70℃下,保持8～10小时;另一种是在70℃水中升温1～1+小时,然后在100℃升温30分钟到一小时。作者设想:破坏过氧化苯酰分子产生游离基所需的热能,如果来自树脂内部,而且能有效地分散,那么聚合就可以很快,产生气泡的危险也小,同时也消除了炉子或热水的热能通过型盒、包埋材、人造石模型等结构转移到树脂本身所需要的时间。微波可以使树脂内部产生热能。民用微波炉使用的频率是2450兆赫兹,波长为12cm。在微波的电磁场中,PMMA分子可以自己定向,在频率为2450兆赫兹的条件下,它们的方向变化几乎
Polymethylmethacrylate (PMMA) is a commonly used resin for oral repair. Its polymerization is an addition reaction that requires initiator (benzoyl peroxide) activation. Benzoyl peroxide is allowed to generate radicals which initiate the polymerization chain reaction by opening the divalent bonds of PMMA. There are two traditional curing methods. One is in a steam oven or water at a constant temperature of 70 ℃ for 8 to 10 hours; the other is in a 70 ℃ water temperature for 1 ~ 1 + hours, and then heated at 100 ℃ for 30 minutes to one hour. The authors hypothesize that the thermal energy required to destroy the radicals generated by the benzoyl peroxide molecules can be very fast if they originate from the interior of the resin and disperse efficiently and the risk of bubble formation is small and the furnace or hot water is also eliminated The heat energy is transferred to the resin itself by the structure of the box, embedding material, artificial stone model and the like. Microwaves can generate heat inside the resin. The frequency of use of civilian microwave oven is 2450 MHz, the wavelength is 12cm. In the electromagnetic field of microwaves, PMMA molecules can be self-orientated and their orientation changes almost at a frequency of 2450 MHz