聚氨酯密封胶试件随着吸湿温度的升高而出现软化现象

发布时间 : 2023-3-24 12:07:41
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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.

聚氨酯密封胶试件随着吸湿温度的升高而出现软化现象

(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 : 2023-3-24 12:07:41
Views:

单轴拉伸过程，始终伴随粘性力和弹性力的作用。弹性力随着拉伸长度的增大呈现出线性化增长，粘性力随着拉伸长度的增大出现先增大后减小的非线性化状态。单轴循环过程，粘性力会受应变范围影响以热能形式耗散，不再发挥作用，而弹性力会继续储存和释放能量。

在恒定的应变加载速率下，材料表现出明显的温度相关性和吸湿度相关性。温度和吸湿度在一定程度上都会影响材料的率相关性和率无关性。在实验室环境条件下，材料表现出明显的应变速率相关性;而在423K的高温和2.6$%2.73%左右的吸湿度状态下，应变速率相关性不明显。

吸湿温度和吸湿时间共同影响了聚氨酯密封胶试件的吸湿度。在常温状态下，由于没有高温的软化作用，使得聚氨酯密封胶试件无法进行吸湿过程。而在高温状态下，吸湿时间越长越易完成吸湿过程，吸湿温度对聚氨酯密封胶试件吸湿度的影响远小于吸湿时间。

气体接触的高温状态与液体接触的高温状态会对聚氨酯密封胶试件产生很大差别的力学性能影响。气体接触的高温状态，聚氨酯密封胶试件随着环境温度的升高而逐渐软化，粘性逐渐增大。而液体接触的高温状态，聚氨酯密封胶试件随着吸湿温度的升高而出现软化现象，但由于水分子的接触，会发生部分的水解反应，聚氨酯密封胶试件吸湿使得粘性减弱。

较高的平均应变加载历史，可使粘接材料失去循环应力松弛现象，粘性力只在循环的第一圈出现。进入下一阶段的循环拉伸后，几乎不出现应力松弛现象。而较低的平均应变加载历史，粘接材料的循环应力松弛会持续出现，每个循环阶段的第一圈都会出现明显的粘性力。进入下一阶段的循环拉伸后，还会产生应力松弛现象。随着循环拉伸的推进，聚氨酯密封胶试件的原始长度会得到延长。

较低的平均应变加载历史比较高的平均应变加载历史更容易引起聚氨酯密封胶试件的断裂。温度升高和循环加载历史会影响材料的循环强度和承受循环加载的能力。循环加载过程中，粘性力的消耗与聚氨酯密封胶试件的拉伸长度有直接关系，弹性力的松弛现象受循环圈数的制约，还与加载历史有关。www.sdyuantai.com

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下一篇: 丁基防水嵌缝胶温度和应变率相关的非线性粘弹性本构模型建立

上一篇: 循环加载历史对硅烷改性聚氨酯密封胶材料的力学性能影响

下一篇: 丁基防水嵌缝胶温度和应变率相关的非线性粘弹性本构模型建立