![\"Polymers](\"http:\/\/www.polymers.com.ua\/image\/data\/%D0%B2%D1%82%D0%BE%D1%80%D0%B8%D1%87%D0%BA%D0%B0\/IMG_0583%D0%9B.JPG\" "\\"Polymers")
<\/a><\/h1>\nIn connection with the expansion of application areas of polymers and improved the technology of their production are installing a large capacity; improved metallocene technology for the production of polyethylene, wherein the polyethylene on metallocene catalysts is developed and by 2015 will reach 25% of the total consumption of polyethylene; a search for new catalysts; develops various compounds for the production of pipes (cross-linked with silane. Gets development the production of new grades of polypropylene, less fragile than currently known. The European Commission developed a new environmentally friendly development program of production and use of PVC.
\nDow Chemicl (USA) has developed a super strong brand of polystyrene. For example, Styron A-Tech 1260 has a high crack resistance and is intended for packing and servirovania food. Another brand, Styron A-Tech 1170 – designed for thermoforming internal vysokozharoprochnyh parts of refrigerators. The need for modification of plastics directly in the extrusion process has arisen in connection with the development of special requirements for products, and the available range of main polymeric materials could not meet the ever increasing requirements Distinguish masterbatches additives – modifiers properties (Additive-Masterbatch and the masterbatch colorants (Color Masterbatch). With the introduction of additives is necessary to consider that any versatile additive effect on the polymeric material, enhancing some features and reducing others. For example, the simple coloring crystallizing material can cause a change in its crystal structure, change, shrinkage and performance characteristics. Supplementation should also be taken into account that the content of transition metals in them can serve as a catalyst for various chemical reactions, including to accelerate the degradation of macromolecules of the polymer. To prevent various types of degradation are heat stabilizers, antioxidants,light stabilizers, deactivator metals, antimicrobial and fungicidal additives (Antioxidant, UV stabilizer, Light stabilizer, Heat stabilizer, Metal deactivator, Antimicrobial biocide, bactericide, fungicide). We differentiate between two types of stabilization: stabilization during processing of the polymer material and a long period of stabilization of the product. Stabilizers and mixtures thereof prevent thermal and fotoatelier degradation of polymers. Deactivator metal surfaces enhance the appearance of plastic parts reinforced with metal at the point of contact with the metal and reduce the harmful effects of ions of polyvalent metals which fall into the product during processing. As desactivation used salt dithiocarbamate, phenolic and nitrogen-containing derivatives such as oxalylbis (benzylidene-hydrazide).
\nThe nomenclature used antimicrobial, fungicidal additives is quite wide, about 20 manufacturers make about 80 names of antimicrobial additives. Currently on the market biostabilization undisputed leader for the arsenic compounds, and more specifically, 10,10-oxybisethanol (OWRA). This connection remains about 70% of the market, due to the optimal ratio of price-quality. As the inorganic antimicrobial systems currently frequently used compounds of silver and zinc. Such compounds are virtually inert and are beginning to shed silver ions (which are known since ancient times as an excellent antibacterial agent) only upon interaction with moisture. The advantages of such compounds are the high thermal stability (up to 500\u00b0C) and very low levels of toxicity. They are approved for use in cosmetic products.
\nFrom technological additives should be called moving, antibioticsa, foaming, cleaning, fluoride supplements, compatibilization, adhesion modifiers, and viscosity (Slip, antiblocking, Blowing agent, Purge agent, Fluoropolymer, Compatibilizer, Adhesion promoter, Viscosity modifier, Crearing agent).
\nThe use of the moving additives (lubricants) is used to improve the appearance of extrusion products, to reduce the forces of friction and adhesion, to prevent sticking of the film roll and to facilitate the unwinding and packages and folders with slip additive can be easily opened. These modifiers increase the fluidity of polymer materials. As the moving additives are used amides of oleic or erucic acids.
\nAmides of stearic and oleic (C18) acids at the expense of shorter hydrocarbon radical quickly migrate to the surface, and a significant reduction of the friction coefficient is observed immediately after extrusion (fast bloom) such sliding additives are used in the packaging line. Stearamide does not contain unsaturated bonds, and therefore has a higher heat resistance and oxidation resistance. Erucamide (C22) has a longer radical, migrates slower but more efficient (slow bloom). It is made from purified vegetable raw materials, more heat resistant and odorless. Such slip additives suitable for the manufacture of packaging for products with high fat content and long storage periods (e.g., mayonnaise). Excess sliding additive adversely affects the effectiveness of the corona treatment and decreases the adhesion of paint.
\nThe most effective method of solving the problem of adhesion of films – add antiblocking, which creates on the surface of the film of micro-roughness, which reduces the contact area of the films. As antiblocking used 2 groups of materials – organic and inorganic.
\nOrganic antiblocking used for making the most of the transparencies, as the micro-roughness on the surface that are created by inorganic antiblocking, increase light scattering and, consequently, the turbidity of the film. For most of the transparencies are recommended to use quartz or talc, and muddy, the best solution is chalk. Unlike moving the additives antiblocking no effect on the corona surface treatment and is capable of improving the adhesion of printing ink due to the roughness on the film surface.
\nFluorinated additives increase the performance of recycling processes, reduce the melt pressure and temperature processing of the polymer. They are poorly compatible with the basic polymers and in places of greatest shear stresses are planted from the melt on the metal surface, creating her anti-adhesive layer, on which slides the melt of the molding. Supplements help to eliminate appearance defects, increase the smoothness of the products.
\nFoaming agents introduced into the polymeric material in the extrusion process reduces the weight and change the appearance of the product. Cleaning concentrates are used for cleaning extrusion equipment, for quick transition from colour to colour without stopping, often in a ratio of 1:1 to 1:3 with the polymer. The composition of the cleaning concentrates are usually soft mineral filler and a surface-active detergent additives.
\nCompatibilization contribute to the achievement of the compatibility of different polymers, fillers, and other additives. These modifiers that chemically interact with the filler and the matrix, and it is better to enter during processing. Such additives include chemically modified polymers – malaysiakini or modified with acrylic acid, polyolefins obtained by the method of reactive extrusion of polyolefins with maleic anhydride and peroxide, copolymerization of acrylic acid with the corresponding monomer. Recently appeared modifier system based on oligomers of unsaturated carboxylic acids (e.g., oleic) and metaphenylene bismaleimide. The main advantage of the latter material is its versatility, i.e., its effectiveness does not depend on the acidity of the filler surface. Modifiers enhance adhesion adhesion to metal (when casting with metal reinforcement) and polymers (for multi-component molding). Viscosity modifiers alter the viscosity of the polymer. As modifiers to increase the viscosity of the used crosslinking agents (organic peroxides).
\nThe functional additives may include antifogs, flame retardants, antistatic agents, modifiers Shine, nucleator, pigments, dyes, sastifactory, photoinitiators destruction, absorbers of infrared radiation, fillers (Flame retardant, Antistatic agent, Gloss control agent, Nucleating agent, Colourant, Impact modifier, IR Absorber). When using greenhouse films water vapor condenses in the form of small droplets on the inner surfaces of the films and can lead to reduced transparency of the greenhouse, as sunlight is reflected and scattered in small drops.
\nSmall droplets of condensate can act as lenses, causing burns the leaves of plants. In addition, small droplets, gathering in large and falling on the leaves of plants, causing various diseases and saturate the air in the greenhouse with moisture, causing the development processes of decay. To get rid of this drawback, in greenhouse films injected is not compatible with the polymer surfactants that migrate to the surface and change the surface tension of the polymer film and water. With close values of the surface tension of the droplets lose their spherical shape and spread, forming a thin layer on the surface of the film. Water flows on the ground and does not damage the plants; greenhouse is transparent to sunlight. The main requirements antifoam are incompatible with the polymer and constant (over time) migration of the additive to the surface.
\nTo obtain a fire resistant composite materials used flame retardants. As flame retardants are substances that release with increasing temperature up to 400\u00b0C, significant quantities of flammable vapors or gases (carbonates, bicarbonates, hydroxides), substances containing microencapsulated liquid (water, halogen-containing low-boiling liquid, freons, substituted phosphates, etc.), and substances that contribute to coxworthy polymers (chlorine – and postergada substances, compounds of phosphorus, nitrogen, boron, silicon and some other elements in combination with<\/p>\n