About plasticizers

Toxicity of phthalate plasticizer

In medical treatment, medical PVC materials such as blood bags and infusion sets are often soft plastic products, and the plasticizer content in the formula can reach 40% to 50%. PVC soft products are also widely used in food packaging materials, children's toys and other downstream industries. Phthalic acid ester is regarded as a kind of environmental endocrine disruptors, academic and industry at home and abroad for the biological toxicity of phthalic acid ester compounds the problem there has always been a major controversy, the study found that phthalates have developmental and reproductive toxicity, especially for in the early development and differentiation of embryo and the harm of children is larger, and even cause mutation.

MEHP and lipophilic oxides will produce two-phase metabolites, which can be coupled with glucuronosides and show higher toxicity. Therefore, in the application field of close contact with human body, it is necessary to strengthen the risk assessment of phthalate esters such as DOP, limit their use scope, and gradually replace them with environmental plasticizers.

Relevant laws and regulations at home and abroad

In December 1999, the European Union was the first to adopt a provisional ban 1999/815/EC on the use of phthalates, banning the use of DINP, DIDP and n-octyl phthalate (DNOP) in children's products that can be placed in the mouth. In the following years, the European Union has issued a limit directive on the content of phthalate esters in food and children's contact materials, among which plasticizers DBP, BBP and DEHP were listed in the first batch of substances of high concern by the European Chemicals Agency (ECHA). At the same time, the US Food and Drug Administration (FDA) announced the maximum amount of DOP in medical plastics such as injections and infusion sets; The Swiss government tried to limit the use of DOP through the proposal of "Swiss Environmental Quality Objectives"; Japan, Denmark, Canada, South Korea and other countries have issued corresponding regulations.

Non - phthalic plasticizer

Epoxy vegetable oil-based plasticizer

Epoxy plant oil based plasticizer is a plant oil based compound containing epoxy group made by vegetable oil through esterification (or transesterification) reaction and epoxidation reaction. Its significant characteristics are non-toxic, environmental protection, good biodegradation, renewable source of raw materials; In addition, the epoxy group in the epoxy plant oil-based plasticizer molecule can absorb THE HCl gas resolved by PVC material in the light and thermal conditions, preventing the catalytic effect of HCl on the continuous decomposition of PVC molecules, which can make the material itself more stable, so as to extend the service life of PVC products. Therefore, it is widely used in plastics, coatings, rubber and other industrial fields. Because use raw material to differ, the kind that epoxy plant oil base kind plasticizer is more, common vegetable oil raw material has: soya bean oil, cottonseed oil, corn oil, sunflower oil, rice bran oil, castor oil to wait. Different molecular weight and structure have obvious influence on the plasticizing energy.

Citrate ester plasticizer

Citric acid ester chemical name for 2-hydroxy-1,2, 3-propane tricarboxylic acid ester, synthetic raw materials are mainly citric acid and fatty alcohol (or aromatic alcohol). Citric acid esters contain hydroxyl groups in their molecular structure that reduce their compatibility with PVC resins, so this hydroxyl group is usually acylated (often acetylated) in industry.

Most citrate esters and acylated citrate esters have high LD50 data. In the international context of increasing restrictions on phthalic plasticizers, various structures of (acylated) citrate esters are widely used in plastic products such as food packaging film, children's toys, drug packaging and medical devices. In addition, its raw materials such as citric acid, C6~C12 straight chain alcohol, acetic anhydride can be obtained from biomass. So the development and application of citric acid ester plasticizer has important practical and economic value. Our country also had successful industrialization produced this kind of plasticizer, dosage is the most, the commonest have citric acid three butyl ester (TBC) and acetyl citric acid three butyl ester (ATBC) two kinds.

Diacid and polyol polyester plasticizer

Saturated polyester plasticizers is mainly composed of glycol was synthesized with dibasic acid through esterification polycondensation, by one yuan alcohol is added in the reaction or a yuan acid as a sealing agent, can obtain different molecular weight and molecular weight distribution of products, it is an important variety of phthalate plasticizers, compared with low molecular weight plasticizers, polyester has the characteristics of migration resistance, high temperature resistant, Therefore, it is considered to be a permanent plasticizer.

Polyester plasticizers has achieved rapid development, our country also has realized industrialization and application of such plasticizer small batch, the largest adipic acid glycol ester application, using the polyester plasticizers, adopts the plasticizer paste process blended with PVC paste resin, can get ideal rigid products, such as toys, shoes, and must have a high frozen products. Polyester plasticizer is also especially suitable for automotive interior, wire and cable, fabric or PVC floor surface decoration, in order to enhance the product resistance to pollution, wear resistance, solvent extraction ability, and can prevent the product water absorption, solvent absorption and expansion. However, the general polyester plasticizing efficiency is poor, due to the large viscosity, compared with the traditional plasticizer products, in the application of research still need to solve the contradiction between durability and processability, low temperature.

Other non - phthalic plasticizers

Cyclohexane dicarboxylic acid ester: since 2002, Germany BASF company launched cyclohexane -1,2- dicarboxylic acid two different nonyl ester (DINCH) and success since, this kind of plasticizer has achieved continuous development, many powerful chemical enterprises have developed a variety of similar structure cyclohexane dicarboxylic acid ester plasticizer. This kind of plasticizer is characterized by no phthalic structure, low toxicity and good compatibility with PVC. At present, it is widely used in the fields with high safety and health requirements such as children's toys and medical devices. In addition, the mobility of some elements in the product meets the international standard of less than 60 mg per kg of food, so it can be used in food cling film, hose or gasket food contact PVC products.

Terephthalate: terephthalate two (2-ethyl) hexyl ester (DOTP), is currently the most used to benzene plasticizer. Different from the ortho-structure of DOP, DOTP molecule is a para-position linear structure. Compared with DOP, in addition to the application of plasticizing performance is slightly worse, the electrical insulation performance of its plasticized PVC products is better, but also has the advantages of heat resistance, cold resistance, extraction resistance and good softness. DOTP is not only permitted in medical and toy products; It is widely used in high temperature resistant PVC cables and other plastic products of volatile to demand higher, DOTP has good compatibility with PVC, also showed a good compatibility with other polymer materials, can be used for acrylonitrile derivatives, polyvinyl butyral, nitrile rubber, acetate plasticizer, also can be used as rubber softener and paper.