Ethylene resin - Names and Identifiers
Ethylene resin - Physico-chemical Properties
Molecular Formula | C4H7Cl
|
Molar Mass | 90.55138 |
Density | 1.22g/mLat 25°C(lit.) |
Use | Used as modifier of polyvinyl chloride, ABS and Other Polyolefins |
Ethylene resin - Upstream Downstream Industry
Ethylene resin - Nature
Open Data Verified Data
The high-density polyethylene is a crystalline high polymer, and as hydrogen atoms in the molecular chain are replaced by chlorine, its crystallinity decreases, it becomes soft, and the glass transition temperature decreases. However, when the chlorine content in chlorinated polyethylene exceeds a certain value, the glass transition temperature increases. Therefore, the glass transition temperature and the melting point of the chlorinated polyethylene may be higher or lower than those of the original polyethylene. The molecular structure of chlorinated polyethylene containing ethylene vinyl chloride 1,2 ethylene copolymer, ordinary chlorinated polyethylene chlorine content of 25% ~ 45% (mass), with the resin molecular weight, chlorine content, different molecular structures and chlorination processes can exhibit different properties from hard plastics to elastomers. Chlorinated polyethylene has excellent weather resistance, cold resistance, impact resistance, chemical resistance, oil resistance and electrical properties, and has the dual properties of plastic and rubber, and with other plastics and fillers have good compatibility. Therefore, it can be filled with a large amount of filler, for example, 100 parts of titanium dioxide or 400 parts of bentonite (or carbon black) in 300 parts of resin. Chlorinated polyethylene with a chlorine content of more than 25% is also self-extinguishing. It can also be crosslinked with an organic peroxide or the like to produce a vulcanizing polymer.
- heat aging resistance CPE is a polymer with a saturated structure, and chlorine is randomly distributed, which does not cause a chain dechlorination reaction when used under heat. This is the reason why CPE is superior to PVC in thermal stability. In general, CPE with low chlorine content is more heat resistant than CPE with high chlorine content. When used as a special synthetic rubber, the curing system with organic peroxide is superior to other curing systems. Epoxy resin is beneficial as a heat stabilizer, while amine and phenolic antioxidants have little effect.
- ozone resistance and weathering aging resistance CPE vulcanizate has good ozone resistance and weathering aging resistance, and can withstand the severe condition test of ozone concentration of 400 × 10 − 6. After ozone aging, almost no cracks were generated.
- The solubility parameter of oil-resistant and solvent-resistant CPE is between 9.2 and 9.3. It has good resistance to aliphatic hydrocarbons, ethanol and ketones, and severe swelling in aromatic and chlorinated hydrocarbons, which are good solvents for CPE, the appropriate variety can be selected to produce the mucilage. CPE has a certain degree of oil resistance, it in a variety of typical oil, such as fuel oil, hydraulic oil, engine oil at different temperatures, the performance of the little change.
- electrical properties CPE is polar and can only be used as a low-voltage insulating material. However, due to its good ozone resistance, heat aging resistance, wear resistance and flame retardant properties, therefore, it is commonly used as a cable sheath material. With the increase of chlorine content, the dielectric constant increases and decreases after reaching the peak value. The higher the frequency, the smaller the chlorine content at the peak value.
- flame-retardant CPE does not burn, under the action of the flame will be covered by a layer of ash that can prevent the spread of the flame, when the chlorine content is increased from 35% to 63%, the amount of such carbonized embers will increase dramatically. Compared with other chlorine-containing flame retardants, CPE is easy to mix with many rubbers and plastics and has good durability, so it is considered to be an economical flame retardant polymer for industrial use. The oxygen index of CPE increased with the increase of chlorine content.
Last Update:2024-01-02 23:10:35
Ethylene resin - Preparation Method
Open Data Verified Data
chlorinated polyethylene (CPE) is a product of polyethylene chlorination. The chlorination reaction is continuously carried out by using light or free radical initiator as a catalyst. After The chlorination requirement is reached, the chlorine supply is stopped and the reaction is terminated. Chlorination reaction can use iodine, aluminum chloride, ferric chloride, organic peroxide as catalyst, slow reaction in the dark, a small amount of oxygen from the catalytic effect and a large number of oxygen inhibition. At present, the methods commonly used in the industrial production of CPE are solution method, gas phase method and aqueous phase suspension method.
- solution method polyethylene and chlorinated hydrocarbon were added to a glass-lined reaction kettle with a stirrer, and the mixture was charged with nitrogen to remove air, and heated to prepare a 5% to 10% solution. After passing the chlorine reaction at a certain temperature and reflux, pour it into the precipitant, recover the solvent, separate the chlorinated polyethylene, and obtain the finished product after washing and drying. The initiators commonly used in solution method include ultraviolet ray, peroxide anisole, azobisisobutyronitrile, ferric chloride, aluminum trichloride, iodine and so on. Solvent in addition to carbon tetrachloride and chloroform, also useful trichloroethane, tetrachloroethane and chlorobenzene and other chlorinated hydrocarbons. The raw material is generally high-pressure polyethylene, but low-pressure polyethylene may also be used. Can be a single chlorination, can also be staged chlorination. This method has the longest history in the production of chlorinated polyethylene, the particle size of the raw material is not high, the process control conditions are simple, and the distribution of chlorine in the product is uniform, it is easy to obtain amorphous rubber elastomer, but the material separation and solvent recovery need more devices, the drying equipment is more complex, the cost is higher, the harm of the solvent to the human body is not easy to protect, and the residual solvent in the finished product is difficult to completely remove, there is smell, the color is yellow, and the white product is not easy to be prepared.
- the gas phase method includes a fixed bed method and a fluidized bed method, and at present, a fluidized bed method is mainly used. Generally, the chlorination reaction is carried out by irradiating a fine powder polyethylene (particle size 5-20 um) in a form of suspension with ultraviolet rays or gamma rays, and using azobisisobutyronitrile as an initiator. In order to speed up the reaction process, the temperature can be increased, and to prevent agglomeration and Coking to maintain the polyethylene powder in a free-flowing state During chlorination, the polyethylene is filled with a water-soluble inorganic powder that will not be chlorinated, or can be acid-washed to the inorganic powder, after the end of the reaction to wash off the additives, after drying the product. The requirements of technology and safety technology for chlorination in fluidized bed are strict. Because the fluidized bed method can be continuously chlorinated, the production capacity is large, but the chlorination near the melting point of polyethylene is easy to cause material bonding and coking, and the recovery of unreacted chlorine and hydrogen chloride is difficult, it is still under continuous research and improvement. There are fewer companies using this method of production.
- aqueous phase suspension process after the emergence of high density polyethylene, this process has become the main production method of chlorinated polyethylene at present. The content of polyethylene in the suspension is 5%~ 20%, which can be suspended in water, hydrogen chloride aqueous solution, etc., and the reaction solution is also added with surfactant and quaternary ammonium salt to prevent the accumulation of static charge, the initiator used is essentially the same as in the case of production by the solution method. The disadvantage is that the equipment is required to have good corrosion resistance, the raw materials need to be crushed, and the chlorination uniformity of the products is not as good as that of chlorinated polyethylene prepared by using a solution method.
- block chlorinated polyethylene (combination of solution and aqueous suspension) according to the temperature of chlorination (above or below the melting point of PE), different configurations of block CPE can be obtained, in order to produce different grades of products.
Last Update:2022-01-01 11:07:17
Ethylene resin - Use
Open Data Verified Data
chlorinated polyethylene with a small amount of PVC, HDPE, MBS modified, can be extruded to produce a variety of resistant tubing, acid tube, waterproofing membrane, profile, film and shrink film. Various molded articles, floors, sealants for construction, covering boards, wire and cable coverings, and various filling material articles can also be produced. Chlorinated polyethylene is used as a modifier for PVC, PE and rubber, which can greatly improve the performance of these products. Chlorinated polyethylene modified rigid PVC, can produce a wide range of soft, semi-soft and rigid plastic. As a toughening modifier for PVC, it can improve its elasticity, toughness and low temperature performance, and the embrittlement temperature can be reduced to -40 ℃, while the weather resistance, heat resistance and chemical stability are far superior to other rubber modifiers, thus, it can be widely used as a building material. As a modifier for polyethylene, printability, flame retardancy, and flexibility can be improved. After adding 5% CPE in HDPE, the bonding force with ink can be increased by 3 times; After adding a small amount of CPE, Sb2 03 and white oil in the formula of mine PE hose, the flame retardancy can be improved, the density of PE foam modified by CPE increases, and CPE can be used as a solubilizer for blending with ABS, PS, PP, PVC and rubber. Chlorinated polyethylene, like desirable plastics, can be applied to the surfaces of metal articles, textiles, paper, glass and wood by gas flame spraying.
- cable sheath rubber sheath began to use Chloroprene Rubber, the use of chlorosulfonated polyethylene in the 50's of the 20th century, to the introduction of CPE in the late 60's of the 20th century. These rubber materials can be used to meet the design and performance requirements of the cable.
- the heat-resistant conveyor belt CPE is used to produce a heat-resistant conveyor belt that is resistant to polar swelling, such as tar, pitch, and the like.
- Industrial rubber pipe is the inherent characteristics of polymer due to the resistance to ozone, weathering aging and flame resistance of CPE, it is much superior to the usual use of a compounding agent that will be extracted to improve these properties, and it also has good extrusion properties, and is therefore suitable for the inner and outer glue of the hose.
- other CPE may also be used as an outer glue layer of a glue roll, used for a press roll for the steel or textile industry or for a transport glue roll of a copying machine. Used as a model rubber products; With styrene-butadiene rubber, ethylene-propylene-diene monomer rubber, etc., have good extrusion performance and weathering aging and other properties, low cost, can be used as automobile and construction industry window panel such as extrusion products. The closed-cell sponge rubber with smooth surface and good aging resistance can be prepared by using it with other rubbers. CPE with a large number of fillers still has enough physical and mechanical properties, can be applied without vulcanization, typical products such as roof waterproofing membrane, magnetic rubber and so on.
- the application of chlorinated polyethylene as the main material to chlorinated polyethylene as the main body, the use of PVC, HDPE, MBS modified, can be used to manufacture the oil pipe, acid pipe, waterproof coil, profile, film and shrink film, etc., can also be coated, injection molding, molding, lamination, welding, bonding and machining. CPE elastomer has achieved good application results in soft PVC products such as waterproofing membrane and film, and in insulated wire and cable jacket materials. China chlorinated polyethylene is mainly used as toughening modifier of rigid PVC, it can improve the elasticity, toughness and low temperature performance of rigid PVC, CPE modified PVC embrittlement temperature can be reduced to -40 ℃, and heat resistance, weather resistance and chemical stability are far superior to other rubber modifiers, so they are widely used in building materials and other fields.
- Application of chlorinated polyethylene modified PE the addition of CPE to polyethylene improves its printability, flame retardancy and flexibility. When CPE and white oil are added to the formulation of mine PE hose, the flame retardancy is improved, and there is no melt during combustion. The density of PE foam Foam modified by CPE increases.
- Application of chlorinated polyethylene as compatibilizer CPE is a compatibilizer of binary blend system, which is used for blending modification with ABS, PS, PP, PE, PVC, rubber, etc. For example, in PVC/PE blends, the toughness, impact strength and plasticization can be significantly improved. The injection molded articles of the blends can be used as mechanical parts, and 1/3 of their products are used in the composite and coating of flakes.
Last Update:2022-01-01 11:07:19
Ethylene resin - Safety
Open Data Verified Data
The outer layer of the product packaging is polypropylene woven bag, lined with polyethylene film bag, and the net weight of each bag is 25kg. During storage and transportation, the warehouse or compartment should be kept dry, clean and well ventilated. Iron hooks should not be used during handling.
Last Update:2022-01-01 11:07:19
Ethylene resin - Molding Process
Open Data Verified Data
Since chlorinated polyethylene contains a large amount of chlorine atoms, it must be synthesized with additives such as heat stabilizers, pigments, fillers and lubricants to preserve its composition and produce the required properties. For example, a thermal stabilizer must be added to the thermoplastic CPE composition to avoid the formation of HC1 by heating. These heat stabilizers must be acid acceptors, such as epoxidized soybean oil, cycloaliphatic epoxy compounds, magnesium oxide and carbonates, and the like. When processed using a hot melt process, antioxidants are added to improve performance, and hindered phenols are used to ensure color stability of the resin at high temperatures. Hindered amines are used as light stabilizers to protect the light stability of the resin. Chlorinated polyethylene can be used in general injection molding, extrusion molding process. Mixed with PVC, can be used in general processing of PVC extrusion into the tube, board, wire coating, profile, film, shrink film; Can also be coated, compression molding, lamination, composite, machining, welding and bonding, etc.
- The CPE used as a plastic can be extruded or injection molded with general processing equipment. During processing, CPE typically requires less plasticizer than PVC, and if the plasticizer content is too high, it may cause surface tackiness. The CPE may also be compatible with low-polarity plasticizers, such as chlorinated paraffin long-chain carbonates, polymeric plasticizers, and the like. The pigments used for CPE are generally carbon black and titanium dioxide, and CPE is compatible with these raw materials; Pigments containing small amounts of zinc and iron will reduce the thermal stability of CPE products. Cross-linked CPE is used as a thermosetting resin. Peroxide is generally used in industry as a curing agent, but the Peroxide curing agent and antioxidant must be matched. If dimercaptodiazepoxide is used as a curing agent, it is less sensitive to antioxidants, but it does not allow the use of chlorinated paraffins and epoxy compounds as additives. CPE is generally a fine, soft particle, very easy to absorb moisture, so it is generally added anti-adhesive. There are also large particles or blocks of CPE, especially hardened, thermosetting elastic CPE, which need to be cut into strips or particles for mixing and then injection molding or compression molding.
- The Mooney viscosity used as the rubber CPE is larger than that of general-purpose rubber. However, processes such as kneading, extrusion, and Calendering can be performed using various techniques and processes commonly used in the rubber industry. (1) because chlorinated polyethylene has no double bond in the molecular chain, it has stability under the action of mechanical shear force, and therefore will not cause molecular chain breaking in the process of mixing in an open Mill, it is a gum chlorinated polyethylene having no mastication effect. Although it has no mastication effect, it is mixed for 3 to 5 minutes before mixing to help the mixing of fillers, plasticizers and other compounding agents. CPE is also very convenient to mix in the internal mixer, and the reverse mixing method is often used, that is, the dry compounding agent is added to the internal mixer first, then the liquid auxiliary agent is added, and finally the raw rubber is added, when the temperature reaches 88~100 ℃, the organic peroxide is added, and the solvent can be discharged at 105~121 ℃ according to the scorch time and vulcanization speed. (2) extrusion the CPE can be extruded using a general-purpose rubber extruder, and a smooth and dense product can be obtained with a good extrusion speed. The CPE can be extruded by an extruder after heat treatment, or can be directly extruded by a cold feed extruder. Due to the good gas permeability resistance of CPE, bubbles are easily generated by bringing in air, therefore, when using the extruder without vacuum pumping device, the temperature should be kept lower, so as not to make the compound too soft to discharge the air inside. A higher extrusion temperature can be used to extrude thermoplastic CPE, but it should be noted that if the temperature exceeds 90 ° C, CPE will accelerate the dehydrochlorination, the temperature of the extrudate must therefore be controlled below this temperature.
- The calendering and polishing CPE has good calendering processing performance, but when the formulation contains a filler such as soft clay, a sticking roll phenomenon may occur. The use of low viscosity varieties of CPE, or with part of the low viscosity CPE of the prepared compound is suitable for fabric paint glue.
- mucilage manufacturing and gluing using a specific CPE compound, using a variety of good solvents can be made for the use of mucilage, commonly used solvents such as dichloromethane, toluene. Prior to the manufacture of the mucilage, the CPE compound is preferably preheated by an open mill, then cut and crushed, and then mixed in a mucilage mixer, so that the ideal mucilage can be obtained more easily. The prepared mucilage can be applied according to the adhesive coating process commonly used in the rubber industry.
- Press-molding vulcanization during press-molding vulcanization, it is necessary to use a release agent to keep the mold clean and easy to open the mold, and a neutral soap solution may be used as the release agent. The use of Ester plasticizers or a small amount of alkane petroleum-based plasticizers in the compound formulation also contributes to demolding. When molding vulcanized chlorinated polyethylene compound, like other halogen rubber, the mold is often corroded by residual hydrogen chloride. Therefore, the mold used in production should be plated with hard chromium.
Last Update:2022-01-01 11:07:18
Ethylene resin - Reference Information
Performance | chlorinated polyethylene, appearance is white powder, non-toxic and tasteless, saturated polymer materials, with excellent weather resistance, ozone Resistance, chemical resistance and aging resistance, with good oil resistance, flame retardant and coloring properties. Good toughness and other polymer materials have good compatibility, high decomposition temperature. |
Use | used as modifier for PVC, ABS and Other Polyolefins derived from thiadiazole; pharmaceutical intermediates |
production method | the use of high-density polyethylene distillation chlorination reaction after the preparation, the process mainly includes solution method, suspension method, suspension solvent method and fluidized bed method. (1) solution method?????? The high-density polyethylene powder with certain characteristics is heated and dissolved in polar solvents such as carbon tetrachloride and chlorobenzene. Under the action of free radical initiator (such as azobisisobutyronitrile, etc.), the chlorination reaction was carried out at a pressure of normal pressure to 0.686MPA. After the chlorine content of the product is qualified, the product is recovered by water analysis and then dehydrated and dried to obtain a non-crystalline and elastic product. The method is easy to control and can produce stable pure chlorinated polyethylene, but the solvent is easy to cause pollution, the recovery process is complex, the energy consumption is large, and it is rarely used in industry. (2) suspension method?????? The relative molecular mass of 100,000-150,000, the particle size of 60 mesh sieve of high density polyethylene powder into containing a certain amount of emulsifier, dispersant and initiator (such as benzoyl peroxide and azobisisobutyronitrile) in aqueous medium, after completion of the emulsification, the temperature was raised to 115-120 ° C., and chlorination was carried out under normal pressure to 0.98MPA and oxygen-free conditions. Control the amount of chlorine and chlorination time, that is, the preparation of a certain amount of chlorine resin. The reaction product is neutralized, washed with water, filtered, centrifuged and dried to obtain a certain degree of crystallinity and elasticity of the product. (3) suspension solvent method????? In the suspension medium, a certain amount of solvent is added, and the chlorination operation is the same as that of the suspension method. (4) fluidized bed method????????? The use of highly dispersed polyethylene powder, in gamma rays or ultraviolet radiation, in the fluidized bed chlorine chlorination, it is also called gas phase method. The process of this method is difficult to control. |
Last Update:2024-04-09 21:11:58