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硅烷改性聚氨酯密封膠的酸性溶液浸泡老化分析
- 發(fā)布時(shí)間 : 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膠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.
- 發(fā)布時(shí)間 : 2025-1-24 18:46:23
- Views:
可知硅烷改性聚氨酯密封膠紫外老化過程中,拉伸剪切強(qiáng)度緩慢下降,2 000 h時(shí),拉伸剪切強(qiáng)度降至1.76 MIa,比初始值下降了約24,破壞類型仍為內(nèi)聚破壞,這說明造成硅烷改性聚氨酯密封膠拉伸剪切強(qiáng)度下降的主要原因是膠層內(nèi)聚強(qiáng)度的下降。
硅烷改性聚氨酯密封膠經(jīng)酸性溶液高溫浸泡老化后,拉伸性能和拉伸剪切強(qiáng)度測試結(jié)果分所示。可知:酸性溶液浸泡老化過程中,拉伸強(qiáng)度逐步下降,1 440 h時(shí),拉伸強(qiáng)度l滌至2.91MPa,比初始值下降了約25。在酸性溶液浸泡試驗(yàn)中,拉伸樣品受到酸性溶液浸泡和高溫的共同作拉伸強(qiáng)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膠片材表面的大分子鏈中存在的氨基甲酸醋基、脈基等極性基團(tuán)發(fā)生水解反應(yīng),水解產(chǎn)生的小分子產(chǎn)物擴(kuò)散到酸性溶液中,導(dǎo)致片材表面逐漸形成凹痕,新形成的凹痕表面的大分子鏈繼續(xù)與酸性溶液反應(yīng),逐漸發(fā)展成為裂紋,在進(jìn)行拉伸測試時(shí),裂紋處易形成應(yīng)力集中而快速斷裂;第二,高溫環(huán)境下酸性水溶液滲透進(jìn)人硅烷改性聚氨酯密封膠本體大分子網(wǎng)絡(luò)中,降低了硅烷改性聚氨酯密封膠大分子之間的氫鍵和其他次價(jià)鍵作用力;同時(shí)酸性水溶液會(huì)造成膠層內(nèi)部發(fā)生水解反應(yīng),導(dǎo)致大分子鏈斷裂,內(nèi)聚強(qiáng)度明顯下降可知:酸性溶液浸泡過程中,拉伸剪切強(qiáng)度快速下降至1.0 MPa左右后趨于穩(wěn)定,比初始值下降了約54%;且在酸性溶液浸泡后,破壞類型由“內(nèi)聚破壞”變?yōu)椤靶〔糠謨?nèi)聚破壞,大部分鋁合金面鉆附破壞”。這說明界面豁附強(qiáng)度發(fā)生了明顯下降,主要原因如下:在高溫環(huán)境下,酸性水溶液會(huì)逐漸滲透至膠層和鋁合金基材的粘接界面處,酸性水溶液對鋁合金造成腐蝕,導(dǎo)致粘接界面發(fā)生開裂私附強(qiáng)度快速下降。http://www.www.mobmib.com/
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