Synthesis and characterization of photocrosslinkable acrylic prepolymers from waste palm frying oil

Abstract

Worsening environmental issues are a result of an increase in the generation of waste palm frying oil (WPFO) and its improper disposal. Due to the enormous volume of WPFO produced by household use and the food industry, new technologies for its reuse in the creation of goods with high economic value are being developed. The use of renewable resources such as WPFO in the polymer industry offers environmental and economic advantages. Deterioration in cooking oil after the frying process is reflected by the decrease in iodine value and increase in free fatty acid (FFA) and acid value. A decrease in iodine value shows a decrease in the content of fatty acids with double bonds and it indicates oxidation of the oil, thus, modification of oil through enzymatic acidolysis is conducted to enlarge unsaturated sites that permit chemical modification. The double bonds and active methylene act as functional sites for the introduction of acrylic polymers. Thus, this research involves adding chemical groups that can polymerize by using WPFO as the precursor. The acrylation process was conducted with the mole ratio of 1:1 (WPFO: acrylic acid) in five neck reactor vessels with nitrogen inlet at 80 ºC for 6 h After the purification process, WPFO acrylic prepolymer was blended with tri-functionality reactive diluents and photoinitiator to become photocrosslinkable acrylic films. The film was cured under UV LED light with 85 % light intensity for 5 min. From the characterization result, WPFO can be considered as a potential waste that can be used as a renewable polymer precursor to replace those that are currently derived from petroleum hydrocarbons thus saving crude oil usage.