Study on Thermal Degradation Effects on Physical Property of Polymers

Polymer is a large molecule composed of repeating structural units connected by covalent chemical bonds. Polymer can be classified into thermoplastics and thermosets. The most significant difference in properties for both of thermoplastics and thermosets in environmental issues are thermoplastic polymers are recyclable while thermoset polymers are not recyclable. Thus, to prevent or reduce environmental pollution, a studies need to be carry out to accelerate degradation rate of the polymer. The main objectives of this project are to investigate and determine the differences of thermoplastic and thermoset polymer when undergo thermal degradation process. The most suitable materials for both thermoplastic and thermoset were selected which are HDPE for thermoplastic and phenolic for thermoset. The HDPE and phenolic were heated in the oven at five different temperatures (50, 70, 90, 105 and 120ºC) to undergo thermal degradation process. After the HDPE and phenolic were allowed to cool to room temperature, parameters changed after the heating process (thermal degradation) were measured. The parameters that were measured are the hardness and weight loss. The results showed that when both HDPE and phenolic undergo thermal degradation, the hardness of HDPE will decrease while for the penolic, the hardness will increase. For the weight loss, both HDPE and phenolic has the same properties which are the percentage of their weight loss will increase when they undergo thermal degradation. These differences between the thermoplastic and thermoset polymer after undergo thermal degradation process will be useful and important to prevent or reduce the environmental pollution.