PVC plasticizer type of presentation

In the processing of PVC , the plasticizer used in applications with various additives to the largest , so it is much higher than other additives investment , even in some formulations softer material than the main raw material of vinyl chloride resin investments. Therefore, the importance of a plasticizer selected without saying lose.
The choice of plasticizers
 PVC is a highly polar polymer , a great intermolecular force , to be heated to a certain temperature in order to show  aluminium stearate the plastic . PVC strong intermolecular forces to make products become hard and inflexible and flexibility. The role of a plasticizer PVC to weaken the force between molecules , thereby reducing the softening temperature , reducing the melt viscosity , increase mobility and improve the processing properties of PVC and products of flexibility.
 Less volatile plasticizer is usually a high boiling ester , a few are a low melting solid , they do not generally react with PVC . Conditions of use of plasticizers with the resin has good compatibility , low price, high plasticization efficiency , plasticized speed, durability ( low volatility Yi shift is small, high extraction resistance ) , environmental stability good ( light, heat resistance, bacterial resistance, chemical resistance and flame retardant ) , health is good ( to people, livestock and crops, non-toxic, non- polluting , tasteless ) , electrical insulation , good viscosity stability is good. However, a plasticizer does not satisfy all the conditions . In actual use , the majority is composed of two or more and for each other, to get the best plasticizing effect and achieve perfect performance requirements. Plasticizer in a formulation used to make the products have reached the optimum value of all the performance is impossible, therefore , to ensure that the choice of plasticizer when the first major performance requirements. Such as children's toys and food packaging and other requirements are mainly non-toxic , beautiful appearance ; plastic sheeting requirements Azodicarbonamide  harmless to crops , light , heat ; wire and cable materials are the main requirements and good electrical insulation . In addition to these requirements, the plasticizer should also focus on the selection of the following factors : PVC resin performance ; product performance required ; plasticizer processing adaptability , cost . Consider the performance of the plasticizer itself , compatibility of the plasticizer most important, it is a plasticizer selected fundamental factors must be considered . Plasticizer and resin compatibility, then plasticized high efficiency , plasticizers no segregation, no exudation , product flexibility and long service life . In the production practice , plasticizers in polymers mainly based on the compatibility with the test quality and experience to determine. Compatibility evaluation method is simple plasticizers, resins , and a suitable solvent by mixing , to prepare a homogeneous solution was slowly cast into a film , its transparency is observed to judge. Homogeneous transparent film represents good compatibility , fuzzy means poor compatibility . Another method plasticizer PVC resin by mixing uniformly heated to plasticizing was cooled to room temperature, and observe any signs of exudate. No description plasticizer exudation good compatibility , oozing plasticizer compatibility explained more worse . According to a general rule, the more similar the easier it immiscible polar . Thus , the solubility parameter of the plasticizer and resin solubility parameter closer . Both compatibility as possible. Dielectric constant is a function of molecular polarity , dipole moment , and it is subject to great influence of hydrogen bonds . Determine the dielectric constant can be used as a plasticizer compatibility parameter. According to the solubility parameter of PVC , plasticizers generally used 8.4-11.4 solubility parameter , dielectric constant of 4-8.
A wide variety of plasticizers
    Phthalate, di (2 - ethylhexyl ) ester referred to DOP, English name Di-(2-ethylhexyl) phthalate. It is phthalic anhydride , and 2 - ethylhexanol the ester obtained as a colorless or light yellow transparent oily liquid. There are two special smell octyl , molecular weight 391 , acid value (mgKOH / g) ≤ 0.10, ester content of 99% -100 % , the relative density of 0.980-0.986 (25 ℃), the viscosity of 80cp (20 ℃), refractive index 1.4830 - 1.4859 (20 ℃), volume resistivity of 1 × 1011Ω · cm. DOP is plastic processing one of the most widely used plasticizer , with excellent overall performance. DOP plasticized high efficiency, low volatility , resistance to ultraviolet light, water extraction , Yi shift is small , and cold resistance, flexibility and electrical performance so well, is a kind of ideal primary plasticizer , but also domestic consumption maximum plasticizer. In Hong Kong, Taiwan and foreign advanced production regions due octanol and price issues and debate on the issue DOP carcinogenic , it has been gradually replaced by other plasticizers . Di-n -butyl phthalate referred DBP, English name Di-n-butylphthalate, from phthalic anhydride and n-butanol esterification colorless oily liquid with an aromatic flavor. Jacket , plastic sheeting . This product is heated and easy to change , with the phenolic antioxidants ( such as bisphenol A) and used to improve this performance.
Phthalate isononylphtalate referred DINP, English name Dinonylphthalate. It is composed of phthalic anhydride with Oxo get nonanol ( mainly 3,5,5 - trimethyl- ethanol ) esterification colorless liquid , molecular weight 419 , acidity ( o- phthalic acid ) < 0.025% ester content of > 99% , the relative density of 0.965-0.972 (25 ℃), viscosity 78-120cp (20 ℃), flash point 219 ℃, refractive index 1.4812 (25 ℃). This product is mainly used as a general-purpose vinyl resin plasticizer , low volatility, Yi shift is small , can give products a good light resistance, heat resistance, aging resistance and electrical insulation. This product is water extractable than DOP good, but Stabilizers for pipe  not as plasticizing efficiency DOP, cold resistance is also poor , not for low temperature applications products. As prices and superior quality reasons DOP, now Hong Kong and Taiwan and foreign advanced countries and regions as the primary plasticizer used to replace DOP use .
Paraffin English name is chlorinated-paraffin, chlorinated paraffin is obtained , having a similar structure of PVC , is a kind of incremental plasticizer. This product is volatile , electrically insulating excellent flame , to give the products a certain luster and tensile strength , can be used as an auxiliary plasticizer PVC resin , replacing part of the main plasticizer to reduce costs. Chlorinated paraffins susceptible to thermal decomposition processing , release hydrogen chloride , hydrogen chloride can catalyze the degradation of PVC resin accelerate decomposition. Therefore, the use of chlorinated paraffin , should match the appropriate thermal stabilizers to prevent decomposition. In addition , the compatibility with PVC, chlorinated paraffin poor elongation and cold products is poor.
 Poly- α- methyl styrene resin English called poly α-methystyremeresin. By α- methyl styrene polymerization, has excellent thermal stability, chemical resistance and electrical properties. Its Yat shift is small, suitable for all kinds of PVC products, the general amount of 10% -20% , the product can improve the electrical insulation products , improve product appearance features and smooth feel .