PVC thermal stability test
DATE：2019/11/23 8:54:16 / READ： / SOURCE：This station
PVC thermal stability test
Thermal stability refers to the resistance of a material to degradation under the action of heat. It is generally measured according to test conditions such as material color, performance and mass loss.
The thermal stability of plastics is a very important property of plastics. It is related to the process conditions of the materials in the forming process, the application range of the products and the operating environment temperature. In particular, plastic materials that are particularly sensitive to heat, such as polyvinyl chloride, are susceptible to heat to liberate toxic and harmful gases. It is difficult to form and process, and at the same time, toxic and harmful gases are released, which pollutes the environment, causes damage to the body of the production personnel, and also corrodes the equipment. Therefore, the determination of the thermal stability of the polyvinyl chloride is more important.
Due to the structure of the polyvinyl chloride itself, the thermal stability of the polyvinyl chloride is seriously affected. It is easy to remove hydrogen chloride under the action of heat to form a conjugated double strand. The conjugated double is a chromophore group, and the color of the resin changes as long as 4-5 conjugated double strands are formed in one molecular chain, and as the number of double strands in the conjugated double strand increases, the resin or The color of the plastic will be yellowish, yellow, orange, and red... one will eventually turn black. Polyvinyl chloride resin begins to decompose a little at a temperature above 140 ° C. The decomposition rate increases with increasing temperature, and a large amount of hydrogen chloride is released above 190 ° C. The processing of polyvinyl chloride is generally carried out at 160-220 ° C. Therefore, a stabilizer is added during the molding process to increase the decomposition temperature of the polyvinyl chloride and prolong the stabilization time. In actual production, in view of molding requirements and cost reduction, the stable stabilizing amount of the resin with good stability can be appropriately reduced, and the amount of the stabilizer should be appropriately increased for the resin having poor stability.
There are many methods for testing the thermal stability of PVC, such as Congo red test paper method, pH method, absorption method, color change method and the like. Among them, the color change method is the most convenient. Therefore, the thermal stability of polyvinyl chloride is often measured by the color change method. The method uses GB/T 9349-2002 standard to determine the thermal stability of polyvinyl chloride.
Thermal stability refers to the resistance of a material to degradation under the action of heat. It is generally measured according to test conditions such as material color, performance and mass loss.
The thermal stability of plastics is a very important property of plastics. It is related to the process conditions of the materials in the forming process, the application range of the products and the operating environment temperature. In particular, plastic materials that are particularly sensitive to heat, such as polyvinyl chloride, are susceptible to heat to liberate toxic and harmful gases. It is difficult to form and process, and at the same time, toxic and harmful gases are released, which pollutes the environment, causes damage to the body of the production personnel, and also corrodes the equipment. Therefore, the determination of the thermal stability of the polyvinyl chloride is more important.
Due to the structure of the polyvinyl chloride itself, the thermal stability of the polyvinyl chloride is seriously affected. It is easy to remove hydrogen chloride under the action of heat to form a conjugated double strand. The conjugated double is a chromophore group, and the color of the resin changes as long as 4-5 conjugated double strands are formed in one molecular chain, and as the number of double strands in the conjugated double strand increases, the resin or The color of the plastic will be yellowish, yellow, orange, and red... one will eventually turn black. Polyvinyl chloride resin begins to decompose a little at a temperature above 140 ° C. The decomposition rate increases with increasing temperature, and a large amount of hydrogen chloride is released above 190 ° C. The processing of polyvinyl chloride is generally carried out at 160-220 ° C. Therefore, a stabilizer is added during the molding process to increase the decomposition temperature of the polyvinyl chloride and prolong the stabilization time. In actual production, in view of molding requirements and cost reduction, the stable stabilizing amount of the resin with good stability can be appropriately reduced, and the amount of the stabilizer should be appropriately increased for the resin having poor stability.
There are many methods for testing the thermal stability of PVC, such as Congo red test paper method, pH method, absorption method, color change method and the like. Among them, the color change method is the most convenient. Therefore, the thermal stability of polyvinyl chloride is often measured by the color change method. The method uses GB/T 9349-2002 standard to determine the thermal stability of polyvinyl chloride.
Author：admin