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硅烷改性聚氨酯密封胶的酸性溶液浸泡老化分析
- 发布时间 : 2025-1-24 18:46:23
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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.
硅烷改性聚氨酯密封胶的酸性溶液浸泡老化分析
(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 : 2025-1-24 18:46:23
- Views:
可知硅烷改性聚氨酯密封胶紫外老化过程中,拉伸剪切强度缓慢下降,2 000 h时,拉伸剪切强度降至1.76 MIa,比初始值下降了约24,破坏类型仍为内聚破坏,这说明造成硅烷改性聚氨酯密封胶拉伸剪切强度下降的主要原因是胶层内聚强度的下降。
硅烷改性聚氨酯密封胶经酸性溶液高温浸泡老化后,拉伸性能和拉伸剪切强度测试结果分所示。可知:酸性溶液浸泡老化过程中,拉伸强度逐步下降,1 440 h时,拉伸强度l涤至2.91MPa,比初始值下降了约25。在酸性溶液浸泡试验中,拉伸样品受到酸性溶液浸泡和高温的共同作拉伸强度下降的主要原因如下:第一,在酸性溶液的作用下,硅烷改性聚氨酯密封胶片材表面的大分子链中存在的氨基甲酸醋基、脉基等极性基团发生水解反应,水解产生的小分子产物扩散到酸性溶液中,导致片材表面逐渐形成凹痕,新形成的凹痕表面的大分子链继续与酸性溶液反应,逐渐发展成为裂纹,在进行拉伸测试时,裂纹处易形成应力集中而快速断裂;第二,高温环境下酸性水溶液渗透进人硅烷改性聚氨酯密封胶本体大分子网络中,降低了硅烷改性聚氨酯密封胶大分子之间的氢键和其他次价键作用力;同时酸性水溶液会造成胶层内部发生水解反应,导致大分子链断裂,内聚强度明显下降可知:酸性溶液浸泡过程中,拉伸剪切强度快速下降至1.0 MPa左右后趋于稳定,比初始值下降了约54%;且在酸性溶液浸泡后,破坏类型由“内聚破坏”变为“小部分内聚破坏,大部分铝合金面钻附破坏”。这说明界面豁附强度发生了明显下降,主要原因如下:在高温环境下,酸性水溶液会逐渐渗透至胶层和铝合金基材的粘接界面处,酸性水溶液对铝合金造成腐蚀,导致粘接界面发生开裂私附强度快速下降。http://www.sdyuantai.com/
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