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通过试验和模拟研究了大量聚合物包括热塑性和热固性聚合物在燃烧过程中的熔化特性。研究发现,在火灾情况下,有些热塑性聚合物如PP,LDPE,EVA-18和PA6等与PMMA相比熔化得较快,并且熔化物很快汽化,很少有熔化物遗留。相反,有些热固性树脂一般不熔化或者只是轻度熔化,如酚醛树脂和环氧树脂。在热塑性聚合物研究中,其熔化特性在温度燃烧阶段影响了质量损失速率。那些快速熔化的热塑性聚合物与PMMA相比,质量损失塑料较低,这跟单个聚合物高温分解机理有关。一般说来,热分解过程杂乱无序的聚合物更容易造成快速熔化。发生热聚作用的聚合物会导致快速挥发,因此熔化较少。开发了一个聚合物燃烧数学模型,能够模拟聚合物燃烧过程中的溶化特性。结果表明,考虑熔化特性的模型模拟结果与锥形量热仪测试结果的相符性比不考虑熔化特性的模型模拟结果的要好。
The melting behavior of a large number of polymers, including thermoplastic and thermosetting polymers, during combustion was investigated experimentally and simulatively. The study found that some thermoplastic polymers, such as PP, LDPE, EVA-18 and PA6, melted faster in the case of fire than PMMA, and the melt vaporized very quickly with little melt left over. In contrast, some thermosetting resins generally do not melt or melt only lightly, such as phenolic and epoxy resins. In the thermoplastic polymer studies, the melting behavior affects the rate of mass loss during the temperature combustion phase. Those fast-melting thermoplastic polymers have a lower mass loss plastic than PMMA, which is related to the single-polymer pyrolysis mechanism. In general, the thermally disordered polymer is more likely to cause rapid melting. Polymers that undergo a thermal polymerization result in rapid volatilization and therefore less melting. A mathematical model of polymer combustion was developed to simulate the melting behavior of polymers during combustion. The results show that the model simulation results considering the melting characteristics are in good agreement with the cone calorimeter test results than the model simulation results without considering the melting characteristics.