分析MS密封胶的TG曲线

发布时间 : 2023-2-27 9:23:54
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(Summary description)Customized SILICONE STRUCTURAL SEALANT from China manufacturer refers to the adhesive with high strength, can bear large load, aging resistance, fatigue resistance and corrosion resistance, and has stable performance within the expected life. It is suitable for bearing the bonding of strong structural parts. Non structural adhesive has low strength and poor durability. It can only be used for bonding, sealing and fixing of ordinary and temporary properties, and cannot be used for structural adhesive bonding. NEUTRAL SILICONE WETHERPROOF SEALANT from China manufacturer is a structural adhesive with waterproof function. Silicone glue refers to the adhesive based on silicone rubber. According to different functions, it can be divided into structural adhesive, potting adhesive, sealant, thermal conductive adhesive, flame retardant adhesive and so on.

分析MS密封胶的TG曲线

(Summary description)Customized SILICONE STRUCTURAL SEALANT from China manufacturer refers to the adhesive with high strength, can bear large load, aging resistance, fatigue resistance and corrosion resistance, and has stable performance within the expected life. It is suitable for bearing the bonding of strong structural parts. Non structural adhesive has low strength and poor durability. It can only be used for bonding, sealing and fixing of ordinary and temporary properties, and cannot be used for structural adhesive bonding. NEUTRAL SILICONE WETHERPROOF SEALANT from China manufacturer is a structural adhesive with waterproof function. Silicone glue refers to the adhesive based on silicone rubber. According to different functions, it can be divided into structural adhesive, potting adhesive, sealant, thermal conductive adhesive, flame retardant adhesive and so on.

发布时间 : 2023-2-27 9:23:54
Views:

对固化后的MS密封胶进行TG-DSC检测分析，结果如图3-5所示。分析MS密封胶的TG曲线，可以分为三部分分析，第一部分:40-200℃，MS密封胶的质量缓慢下降，下降原因可能是水分和低分子物质的挥发。在200℃时，MS密封胶的质量损失率为1.44%。第二部分:200-380℃范围内，MS密封胶的质量下降速度加快，这可能是由硅橡胶的侧链甲基发生断裂和端经基发生反应所导致的。第三部分:当温度高于450℃时，MS密封胶的分子主链开始发生激烈分解，质量开始急剧下降，MS密封胶完全失效。说明该MS密封胶在200℃以下有较好的耐温性能。结合第一种耐温性试验，在200℃,115h时发生粉化，说明不能够在200℃以上长期使用。由图可知，热老化试验前后，拉伸剪切试板的破坏方式均为附着破坏。热老化后，拉伸剪切试板内部的128环氧树脂涂层颜色变为红棕色，5组搭接剪切强度的平均值由7.12MPa提高至13.32MPa。因此，推测128环氧树脂在高温下继续交联，分子间结合力进一步增强，牖牡慕岷锨慷刃∮贛S密封胶的内聚力。从图片可以看出，环氧树脂在高温下颜色变化明显，出现了老化现象，无法在200℃的工况环境中长期使用。进一步对固化后的环氧树脂的耐温性检测，将固化后的样品切成块状颗粒，放入200℃的电热鼓风干燥箱中。热老化2h,8h和16h后，观察外观并测定环氧树脂的质量变化。试验后的样品形貌如图5-2所示。质量变化情况如表5-1所示。由图5-2可知，经过热老化后，环氧树脂的颜色逐渐由浅黄色变为红褐色、黑灰色，最终变为黑色。在200℃，老化8h基本完全失效。质量未出现明显下降，说明该环氧树脂内的水分子及低分子易发物质含量较低;但不能长期在200℃下服役。因此，不能作为TRT桦槽的密封材料。对硅橡胶涂料的拉伸剪切强度进行测定。根据试验方案2.3.1进行试验并测定硅橡胶涂料的老化前后拉伸剪切强度。在200℃的电热鼓风干燥箱中，5天后出现试样板上的硅橡胶开裂，如图5-3(b)所示。与经销商沟通后，明确了出现该现象的根本原因在于该款硅橡胶涂料属于湿气固化型涂料，涂料吸水膨胀，当膨胀力大于MS密封胶与金属基材之间的结合力时，拉伸剪切试板在涂料搭接部位开裂。因此，若将该涂料涂于TRT叶根和桦槽之间，该涂料极有可能无法固化，从开裂推测硅橡胶与金属基体的粘结性不好，假如在运行过程中硅橡胶出现开裂，TRT内的煤气以及酸性分子会渗入桦槽之间，易发生腐蚀现象。即使固化，硅橡胶发生吸水膨胀也会对叶根和桦槽产生较大的作用力，不利于装置的运行。www.sdyuantai.com

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