A polymer antistatic method overview
Polymer surface charge gathered depends on the polymer itself on the nature of the charge discharge, the main discharge for the surface conduction, conductivity and radiation to the surrounding air, the three surface conduction as the main pathway. Because the surface conductivity is generally greater than the volume conductivity, so the electrostatic force on the surface of the polymer is mainly governed by the surface conductivity of the polymer that makes it up. Therefore, by increasing the polymer surface conductivity or volume conductivity so that the polymer material quickly discharged can prevent the accumulation of static electricity. Antistatic agent is a class added to the resin or coated on the surface of the polymer material to prevent or eliminate the generation of static electricity chemical additives, add antistatic agent is an effective way to improve the surface conductivity of polymer materials, and improve the volume conductivity of polymers can be used to add a conductive filler, add antistatic agent or with other conductive molecules **** mixing technology, etc..
(A) add conductive filler
This method is usually a variety of inorganic conductive filler doped into the polymer material matrix, the current method of inorganic conductive filler is mainly used in this method of carbon filler, metal filler, etc..
(B) and structural conductive polymer materials **** mix
Conductive polymer materials in the polymer (or polymer) is composed of many small recurring structural units, when the material is added to the ends of a certain voltage, the material has a current through the material, that is, with the nature of the conductor, where the same time, with the above two properties of the material known as conductive polymer materials. Different from the metal conductor, it belongs to the molecular conductive material. Fundamentally speaking, such conductive polymer materials themselves can be used as antistatic materials, but because of the general molecular rigidity of such polymers, insoluble and fusible, molding difficulties, easy to oxidize and poor stability, can not be directly applied alone, generally as a conductive filler and other polymer matrix **** mixing, made of antistatic composite materials, such antistatic polymer composites have better compatibility, the effect of a better and more This kind of antistatic polymer composite material has better compatibility, better effect and more durable.
(C) add antistatic agent method
1. Organic small molecule antistatic agent. Organic small molecule antistatic agent is a class of organic substances with surfactant characteristics of the structure of the general formula for RYx, in which R is a lipophilic group, x is a hydrophilic group, Y for the connection group. Molecular non-polar part of the lipophilic group and the polar part of the hydrophilic group should have a proper balance between the polymer material and a certain degree of compatibility, C12 or more alkyl is a typical lipophilic group, hydroxyl, carboxyl, sulfonic acid and ether bond is a typical hydrophilic group, such organic small molecules can be divided into cationic, anionic, nonionic and amphoteric type of antistatic agent of four categories: cationic antistatic agent ; anionic antistatic agent; nonionic antistatic agent; amphoteric antistatic agent.
Conductive mechanism, whether it is coated with external or internal type, polymer materials with the role of antistatic agent mechanism mainly has the following four: (1) antistatic agent hydrophilic group to increase the hygroscopicity of the product surface to absorb water molecules in the air, the formation of the "sea of an island" type of conductive film of water. (2) Ionic antistatic agent to increase the ionic concentration on the surface of the product, thereby increasing the conductivity. (3) The dielectric constant of the antistatic agent can increase the dielectric properties of the friction body gap. (4) Increase the surface smoothness of the product, reduce the surface friction coefficient. To summarize one is to reduce the surface resistance of the product, increase electrical conductivity and accelerate the leakage of electrostatic charge; the second is to reduce the friction charge generation.
2. Permanent antistatic agent. Permanent antistatic agent is a class of hydrophilic polymers with large relative molecular mass, they have good compatibility with the matrix resin, and thus the effect is stable, long-lasting, better performance. Their degree of dispersion in the matrix polymer and the state of dispersion of the matrix resin antistatic properties have a significant impact. Hydrophilic polymer in the presence of special phase solvents, by the lower shear force stretching effect, in the matrix polymer surface is a fine ribbed, that is, the layered dispersion structure, and the center part of the spherical distribution, this "pistil shell" structure of the hydrophilic polymer in the layered dispersion state can effectively reduce the surface resistance of **** mixture, and has a permanent antistatic properties. Permanent antistatic properties.
Two, China's polymer materials, the development of antistatic technology
Many of China's scientific research institutions and production enterprises have developed a number of varieties of non-ionic surfactant-based, commonly used varieties are developed by the Dalian Light Industry Research Institute of hardened cottonseed mono-glycol, ABPS (alkylphenoxypropanesulfonic acid sodium), DPE (alkyl diphenyl ether sulfonic acid potassium); Shanghai, the development of additives plant currently produced by a number of enterprises. Additives Plant to develop the current production of a number of enterprises antistatic agent SN (octadecyl hydroxyethyl dimethylamine nitrate), in addition to the plant's production of antistatic agent PM (dimethyl sulfate and ethanolamine complex), antistatic agent P (phosphate ester and ethanolamine condensate); Beijing Research Institute of Chemical Technology developed ASA 10 (three-component or two-component monoglyceride stearate complex), ASA 150 (cationic and nonionic surfactant complex), ASA 150 (cationic and nonionic surfactant complex), ASA 10 (three-component or two-component stearic acid), ASA 150 (cationic and nonionic surfactant complex). and nonionic surfactant complex), and in recent years, ASH series, ASP series and AB series products have been developed, in which ASA series antistatic agent consists of fatty acid esters of polyols, polyoxyethylene compounds and other nonionic surfactants; ASB series products are organic boron surfactants (mainly fatty acid esters of boronic acid bis-polyol esters and ethylene oxide adducts) compounded with other nonionic surfactants; ASH and ASH series products are organic boron surfactants (mainly fatty acid esters of boronic acid bis-polyol esters and ethylene oxide adducts) compounded with other nonionic surfactants. Composite; ASH and ASP series are mainly cationic and nonionic surfactant composite, Hangzhou Research Institute of Chemical Technology developed HZ a 1 (hydroxyethyl fatty amine and some with the agent complex), CH (alkyl alcohol amide); Tianjin Institute of Synthetic Materials Industry developed IC a static dissipative (imidazole a calcium chloride complex); Shanghai Synthetic Detergents Factory developed and produced SH series of plastic Antistatic agent, has formed a series of products, in the use of the effect and performance of the leading position in China, some varieties can replace imports, such as SH a 102 (quaternary ammonium amphoteric surfactants), SH a 103, 104, 105, etc. (are quaternary ammonium cationic surfactants), SH antistatic agent belongs to the structure of the newer with more hydroxyl group of cationic surfactants; Jinan Research Institute of Chemical Engineering JH a nonionic antistatic agent. (polyoxyethylene alkylamine complex), etc.; Henan University developed the KF series, such as KF a 100 (nonionic polyhydroxy long carbon chain type antistatic agent), KF-101 (ether structure, polyhydroxy cationic permanent antistatic agent), in addition to polyoxyethylene ether antistatic agent, polyethylene, polypropylene and PVC special antistatic agent 202, 203, 204, etc.; antistatic agent TM series products are also commonly used in China, mainly used in the field of synthetic fibers.
From the point of view of the development of antistatic agents, polymer-type permanent antistatic agent is the most promising products, especially in the field of precision electrical and electronic, a number of domestic scientific research institutions using polymer alloying technology to develop a high molecular weight permanent antistatic agent has made significant progress.
Three, conclusion
China's synthetic materials antistatic agent industry development prospects are better for the current domestic research, production, application and demand for the status quo, the development of China's synthetic materials antistatic agent industry to put forward the following recommendations.
(A) increase the development of new varieties
In recent years, foreign countries to develop high-performance primary alcohol polyoxyethylene ether nonionic surfactants; used in polycarbonate fatty acid monoglycidyl ester; used in the tape industry with the addition of polychlorinated vinyl ether alcohol phosphoric acid derivatives; adapted to polyolefins, PVC, polyurethane and other synthetic materials such as polyalcohol fatty acid ester and Melamine adducts, etc. In short, the domestic research institutes should be based on the requirements of China's synthetic material products, to develop a variety of high-performance, environmentally friendly and non-toxic antistatic varieties, and constantly strengthen the application of technical research to meet domestic demand.
(2) accelerate the composite antistatic agent and masterbatch research and production
In the future, we should speed up a variety of structural antistatic agent and other plastics additives compound, to adapt to a wide range of high efficiency, serialization, multifunctionality, composite and other directions. In addition to synthetic materials, multifunctional masterbatch as an additive has become an important raw material for the future processing modification of synthetic resins, such as coloring, flame retardant, antimicrobial, nucleation and other masterbatch in the domestic development of the booming domestic to speed up the development of antistatic masterbatch development and research, and to promote the development of China's antistatic agent industry.