Hygienic problems of plastics and their products (VIII)
(VIII) unsaturated polyester resin and its glass fiber reinforced plastics
1. Physical and chemical properties: unsaturated polyester resin is a liquid unsaturated polyester resin made of polyol, unsaturated dicarboxylic anhydride, saturated dicarboxylic anhydride as the main raw materials, and the polyester is generated under the action of initiator and vitamin, and then added with styrene. Unsaturated polyester resin products made of glass fiber as reinforcement material are called glass fiber reinforced plastics, also known as glass fiber reinforced plastics. FRP has the characteristics of convenient molding, cold resistance, light weight, impact resistance and so on. Therefore, unsaturated polyester and its glass fiber reinforced plastics are mainly used to make storage plates for frozen fish, wine and seasoning fermenters until the rubber pattern is torn off. After the main load is loaded, there is a jump, cold storage and water tank storage plates, etc.
2. Main health problems: unsaturated polyester resin and its glass are non-toxic except for the materials we provide. The oral LD50 of unsaturated polyester resin is 15 kg/kg body weight, which is mutagenic. Therefore, the normal force required is that the tests (Ames test, micronucleus test and sperm malformation test) are negative. However, initiators and catalysts need to be used in the polymerization and curing of unsaturated polyester resin and its FRP. Therefore, there will be residues of initiators and catalysts in unsaturated polyester resin and its FRP. There are many kinds of initiators and catalysts, some of which are toxic. GB "Hygienic standard for the use of additives for food containers and packaging materials" stipulates that unsaturated polyester resin and its FRP used for food containers and packaging materials should use methyl ethyl ketone peroxide as initiator and cobalt naphthenate as catalyst. In addition, styrene is not only the solvent of unsaturated polyester resin and its FRP, but also its curing crosslinking agent. Therefore, the residue of styrene is inevitable, and ethylbenzene is often mixed in styrene. Styrene has great toxicity. The residue of styrene is related to the proportion of initiator and catalyst, formula, curing degree and molding treatment. According to GB hygienic standard of unsaturated polyester resin for food containers and packaging materials and its glass fiber reinforced plastics, ethylbenzene compounds (calculated as styrene) in unsaturated polyester resin templates for food containers and packaging materials and glass fiber reinforced plastics should be controlled below 0.2% and 0.1% respectively.
source: Jinshi Group
Copyright © 2011 JIN SHI