不同多元醇对丁基防水嵌缝胶之XRD曲线熔融温度和剪切强度等影响

发布时间 : 2025-3-20 12:19:33
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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.

不同多元醇对丁基防水嵌缝胶之XRD曲线熔融温度和剪切强度等影响

(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 : 2025-3-20 12:19:33
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以聚醋多元醇或聚醚多元醇为软段、芳环及二异氰酸醋链段为硬段，制备丁基防水嵌缝胶。其中软段多元醇的主链结构(尤其是非晶态结构)对丁基防水嵌缝胶的力学性能、粘接性能和熔融温度等影响较大，前者的结晶度、结晶速率以及结晶形态是直接决定后者的力学性能、粘接性能和光学性能等重要因素。通常，丁基防水嵌缝胶具有良好的柔韧性、低温性能和耐水性能，但其粘接强度较低;丁基防水嵌缝胶中的酷基极性较大，并且醋基的内聚能(12.2 kJ/mol)远大于醚基的内聚能(4.2 kJ/mol)，故丁基防水嵌缝胶具有分子间作用力大、内聚强度和力学强度高等特点。

综合考虑强度、熔融温度和柔韧性等因素，本研究选用结晶性良好的聚醋多元醇和聚醚多元醇作为软段主体，同时采用聚酷多元醇和聚醚多元醇共混法来适度破坏软段的结晶，以达到降低丁基防水嵌缝胶的熔点、改善其粘接强度等目的。多元醇结晶性对HMA性能的影响热塑性丁基防水嵌缝胶受热后会失去氢键作用，变成熔融的勃稠液，冷却后又能恢复原来的理化性能。丁基防水嵌缝胶的粘接强度主要由物理固化产生的分子间作用力所提供，而分子间作用力与软段的结构、类型、结晶性及软/硬段微相分离程度等密切相关。

聚醚多元醇是指分子主链结构上含有醚键、端轻基的醇类聚合物或齐聚物，由于其结构中醚键的内聚能较低(易内旋转)，故由其合成的丁基防水嵌缝胶具有良好的低温性能、柔韧性和耐水解性能，但其粘接强度较低。具有一定结晶度的聚合物，其聚集体中含有更多的微晶结构(起缠结点和固定点作用)，故其在拉力作用下有更多的链段可伸展受力(形变和破坏既涉及到分子链的滑移，又涉及到化学键的破坏);由于微晶的固定和补强作用，使结晶型聚合物比无定形聚合物具有更高的力学强度L21，但结晶度的提高也将导致聚合物熔点的提升，故必须设计软段的结晶度。在其他条件保持不变的前提下(如以多元醇为软段、MDI链段为硬段和R=0.98等)，考察了不同多元醇对丁基防水嵌缝胶之XRD曲线、熔融温度和剪切强度等影响，结果如图1、表1所示。http://www.sdyuantai.com/

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