为了研究交流电晕对室温硫化(room temperature vulcanization,RTV)和高温硫化(high temperature vul-canization,HTV)硅橡胶憎水性丧失和恢复的影响,基于硅橡胶电晕测试系统在相同的温度、湿度和场强下对同样厚度的RTV和HTV硅橡胶进行...为了研究交流电晕对室温硫化(room temperature vulcanization,RTV)和高温硫化(high temperature vul-canization,HTV)硅橡胶憎水性丧失和恢复的影响,基于硅橡胶电晕测试系统在相同的温度、湿度和场强下对同样厚度的RTV和HTV硅橡胶进行了电晕,测量了不同电压和电晕持续时间情况下RTV和HTV硅橡胶在电晕和恢复时的静态接触角随时间的变化情况。研究发现:同样的电压和加压时间情况下,RTV硅橡胶电晕后憎水性丧失速度慢于HTV硅橡胶,憎水性恢复到初始值所需时间明显短于HTV硅橡胶。随电晕时间的增加硅橡胶憎水性恢复到初始值所需时间存在增加的趋势。随电晕电压的增加硅橡胶憎水性下降速度加快,憎水性恢复到初值所需时间存在增加的趋势;随电晕时间、电压的增加晕圈逐渐增大。电晕的开始阶段憎水性快速下降,随时间增加速度逐渐下降,后来憎水性逐渐趋于稳定;恢复的开始阶段憎水性恢复速度快,随时间增加速度逐渐下降,后来憎水性逐渐趋于稳定。对电晕后硅橡胶表面进行了扫描电镜(scanning electron microscope,SEM)分析,发现RTV硅橡胶表面破坏情况比HTV硅橡胶严重。展开更多
研究室温硫化(room temperature vulcanization,RTV)硅橡胶涂层染污后憎水性迁移及其影响因素对RTV的应用具有指导意义。笔者以盐和灰的混合物模拟现场污秽,通过静态/动态接触角法表征憎水性,研究了迁移时间、温度、湿度、盐类型、灰类...研究室温硫化(room temperature vulcanization,RTV)硅橡胶涂层染污后憎水性迁移及其影响因素对RTV的应用具有指导意义。笔者以盐和灰的混合物模拟现场污秽,通过静态/动态接触角法表征憎水性,研究了迁移时间、温度、湿度、盐类型、灰类型、盐密、灰密对RTV涂层憎水性迁移速度的影响。结果表明:随着迁移时间的增加憎水性逐渐变好,迁移完全样本的接触角大于洁净样本;随温度增加迁移速度变快,且温度越高速度增加越快;随相对湿度增加迁移速度减慢,迁移所需时间非线性增大;ZnSO4迁移速度最快,NaNO3、NaCl、CaSO4相近;灰为硅藻土时污层的迁移速度快于高岭土的;随盐密/灰密(污秽度)的增加迁移速度有下降的趋势。展开更多
Casting is an important rubber manufacturing process for both production and material developments. A quick and flexible way of testing the constitutive materials properties of rubber products is very important for op...Casting is an important rubber manufacturing process for both production and material developments. A quick and flexible way of testing the constitutive materials properties of rubber products is very important for optimising the processing parameters and quality control. In many cases, standard tests such as tensile or compression tests are time consuming and require a large volume of materials. This work reports some recent work in using a combined numerical and experimental approach to characterise the properties of rubber materials during a casting process. Durometer shore hardness is used to test silicone rubbers (as a model material) with different compositions on different moulding planes and the linear elastic property is estimated from the hardnesses. The predicted properties are systematically compared with the experimental tests on hard and soft silicone rubber samples with different compositions. The work shows that shore hardness can be used as an effective way to monitor the materials properties during amoulding process for process optimisation and quality control.展开更多
文摘为了研究交流电晕对室温硫化(room temperature vulcanization,RTV)和高温硫化(high temperature vul-canization,HTV)硅橡胶憎水性丧失和恢复的影响,基于硅橡胶电晕测试系统在相同的温度、湿度和场强下对同样厚度的RTV和HTV硅橡胶进行了电晕,测量了不同电压和电晕持续时间情况下RTV和HTV硅橡胶在电晕和恢复时的静态接触角随时间的变化情况。研究发现:同样的电压和加压时间情况下,RTV硅橡胶电晕后憎水性丧失速度慢于HTV硅橡胶,憎水性恢复到初始值所需时间明显短于HTV硅橡胶。随电晕时间的增加硅橡胶憎水性恢复到初始值所需时间存在增加的趋势。随电晕电压的增加硅橡胶憎水性下降速度加快,憎水性恢复到初值所需时间存在增加的趋势;随电晕时间、电压的增加晕圈逐渐增大。电晕的开始阶段憎水性快速下降,随时间增加速度逐渐下降,后来憎水性逐渐趋于稳定;恢复的开始阶段憎水性恢复速度快,随时间增加速度逐渐下降,后来憎水性逐渐趋于稳定。对电晕后硅橡胶表面进行了扫描电镜(scanning electron microscope,SEM)分析,发现RTV硅橡胶表面破坏情况比HTV硅橡胶严重。
文摘研究室温硫化(room temperature vulcanization,RTV)硅橡胶涂层染污后憎水性迁移及其影响因素对RTV的应用具有指导意义。笔者以盐和灰的混合物模拟现场污秽,通过静态/动态接触角法表征憎水性,研究了迁移时间、温度、湿度、盐类型、灰类型、盐密、灰密对RTV涂层憎水性迁移速度的影响。结果表明:随着迁移时间的增加憎水性逐渐变好,迁移完全样本的接触角大于洁净样本;随温度增加迁移速度变快,且温度越高速度增加越快;随相对湿度增加迁移速度减慢,迁移所需时间非线性增大;ZnSO4迁移速度最快,NaNO3、NaCl、CaSO4相近;灰为硅藻土时污层的迁移速度快于高岭土的;随盐密/灰密(污秽度)的增加迁移速度有下降的趋势。
文摘Casting is an important rubber manufacturing process for both production and material developments. A quick and flexible way of testing the constitutive materials properties of rubber products is very important for optimising the processing parameters and quality control. In many cases, standard tests such as tensile or compression tests are time consuming and require a large volume of materials. This work reports some recent work in using a combined numerical and experimental approach to characterise the properties of rubber materials during a casting process. Durometer shore hardness is used to test silicone rubbers (as a model material) with different compositions on different moulding planes and the linear elastic property is estimated from the hardnesses. The predicted properties are systematically compared with the experimental tests on hard and soft silicone rubber samples with different compositions. The work shows that shore hardness can be used as an effective way to monitor the materials properties during amoulding process for process optimisation and quality control.
