影响环氧树脂胶耐高温强度性能的主要因素

摘要: 高温环氧树脂粘合剂取决于固化产物和热氧化稳定性的热变形温度。前者决定在高温(强度,模量,蠕变等),它决定了极限温度(分解温度)的机械性能。这完全取决于该树脂和固化剂和反应性相互的分...

高温环氧树脂粘合剂取决于固化产物和热氧化稳定性的热变形温度。前者决定在高温(强度,模量,蠕变等),它决定了极限温度(分解温度)的机械性能。这完全取决于该树脂和固化剂和反应性相互的分子结构。通常,交联点之间的更短的,更大的交联密度,芳香环的分子链,脂环,杂环基等。更耐热刚性较高的热变形温度,高温机械更高的性能固化距离,更好的耐热性,但也有较大的脆性。大会降低脆性的强度,它通常是被增韧。热氧化稳定性是固化的热氧化破坏性的能力。它与固化分子的化学结构。您可以添加抗氧化剂来提高。

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一般在无氧气之间存在时,环氧树脂本体热影响分解工作温度在300℃以上。而在中国空气环境中使学生用时,一般在180~200℃就会导致发生进行热氧化技术分解。在此过程中温度下老化需要一段发展时间,强度不断下降就更大。多数脂环族环氧树脂在200℃以下问题比较系统稳定,但在利益高于200℃时热氧化处理破坏比双酚A型环氧树脂更严重。这可能是脂环不如芳环稳定的缘故。芳香胺固化的双酚A型环氧树脂的热氧化过程稳定性比脂环或芳环酸酐物质固化的双酚A型环氧树脂差。因为在胺类固化的环氧树脂体系结构设计中有比较多的羟基。在较低的温度下就易于学习产生不同脱水可以反应。此外胺类上的N原子也比较简单容易出现遭受热氧化破坏。而酸酐形成固化物中很少能够生成一个羟基。但在290℃以上分析两类固化剂的环氧固化物分子主链都会选择开始通过断裂。由上可知,双酚A型环氧树脂的耐高温性较差。酸酐作为固化物的耐高温性优于传统芳香胺固化物。

通常,这需要耐高温性也高了系统的固化温度。对于这一现象,其本身由于环氧树脂和硬化剂的耐高温性往往在高温下活性较低固化完全,因此耐高温性。

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High temperature depends on curing epoxy adhesive products and heat deformation temperature of thermal oxidation stability. The former decision under high temperature (strength, modulus, creep, etc.), it determines the limit temperature on the mechanical properties of the decomposition temperature (). It all depends on the resin and curing agent and the molecular structure of reactive with each other. Usually, the junction between the shorter, the crosslinking density of the larger, aromatic ring chain, alicyclic, heterocyclic base, etc. More heat-resistant rigid high heat distortion temperature, high temperature mechanical solidification distance higher performance, better heat resistance, but also have greater brittleness. Reduce the strength of a brittle, it is usually be toughening. Thermal oxidation stability is the ability of curing the thermal oxidation of destructive. Its chemical structure with curing molecules. You can add antioxidants to improve.


Generally, in the absence of oxygen between epoxy resin body heat decomposition temperature above 300 ℃. And to make the students in China's air environment, is in commonly 180 ~ 200 ℃ will cause thermal oxidation technology decomposition. In the process temperature ageing needs a development time, strength is declining. Most of alicyclic epoxy resin system stable compared under 200 ℃, but in the interests of higher than 200 ℃ when the thermal oxidation treatment failure is more serious than that of bisphenol A type epoxy resin. This may be alicyclic as aromatic ring is stable. Aromatic amine curing bisphenol A type epoxy resin, the thermal oxidation stability of the material than alicyclic or aromatic ring anhydride curing bisphenol A type epoxy resin. Because of the amine cured epoxy resin system in the design of housing have more hydroxyl groups. At low temperature is easy to learn can produce different dehydration reaction. In addition the N atom on the amine is easy to appear thermal oxidative damage. Formation and anhydride curing are rarely able to generate a hydroxyl group. But in the 290 ℃ above analysis two types of curing agent of epoxy curing the molecular main chain can choose to use. By the knowable, high temperature resistance of bisphenol A type epoxy resin was poor. Anhydride as curing of high temperature resistance is superior to the traditional aromatic amine curing.


Usually, it need high temperature resistance and high the curing temperature of the system. For this phenomenon, in itself because of the high temperature resistance of epoxy resin and hardener often active low curing at high temperature completely, therefore the high temperature resistance.


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