| Customization: | Available |
|---|---|
| CAS No.: | 68648-82-8 |
| Formula: | C4h5cl3 |
|
Still deciding? Get samples of $ !
Request Sample
|
Suppliers with verified business licenses
Audited Supplier Audited by an independent third-party inspection agency
Weifang Phoenix New Material Co., Ltd
| PROJECT | Test Standards | HT-112 | HT-120 |
| Appearance | Q/DHXJ 008 | 30±1 | 36±1 |
| Density g/cm³ | GB/T 1033.1 (Eqv ISO 1183) |
1.5 | 2.0 |
| Tensile strength MPa | GB/T 1040.2 (Eqv ISO 527) |
0.30 | 0.30 |
| Tensile elastic modulus MPa | GB/T 1040.2 (Eqv ISO 527) |
40 | 40 |
| Izod notched impact strength kJ/m² | GB/T 1843 (Eqv ISO 180) |
65 | 60 |
| Vicat softening temperature ºC | GB/T 1633 (Eqv ISO 306) |
8.0 | 8.0 |
| Oven test | GB/T 9349 (Eqv ISO 305) |
700 | 1000 |
Properties
Chlorinated polyvinyl chloride is a new type of engineering plastic made by chlorination modification of polyvinyl chloride (PVC) resin. The product is white or light yellow, tasteless, odorless, non-toxic loose particles or powder. After chlorination of PVC resin, the irregularity of molecular chain arrangement increases, polarity increases, solubility of resin increases, chemical stability increases, thus improving the heat resistance of the material and corrosion resistance to acids, alkalis, salts, oxidants, etc. The mechanical properties of the heat deformation temperature of the resin are improved, the chlorine content is increased from 56.7% to 63-69%, the Vicat softening temperature is increased from 72-82ºC to 90-125ºC, the maximum use temperature can reach 110ºC, and the long-term use temperature is 95ºC. Therefore, CPVC is a new type of engineering plastic with broad application prospects.
Uses
Also known as (poly) perchlorethylene. A polymer compound obtained by chlorination of polyvinyl chloride. Chlorine content is 61%~68%. It has thermoplasticity. White powder. Not easy to burn. Resistant to concentrated acid, concentrated alkali, mineral oil, etc., the products do not deform in boiling water. It is more soluble in organic solvents such as esters, ketones, aromatic hydrocarbons, etc. than polyvinyl chloride. It is used to make corrosion-resistant paints, adhesives and synthetic fibers.
CPVC has excellent high temperature resistance, corrosion resistance and flame retardancy, and compared with other thermoplastic engineering plastics, its price is relatively low. Therefore, CPVC has a wide range of uses. It is widely used in hot and cold water transportation in residential areas, hotels and restaurants, and industrial pipeline water supply systems; cable pipes, special-shaped doors and windows and other building materials; decorative materials in aircraft and materials for cars and lamps; CPVC sheets can be welded into different equipment; in addition, it is also widely used in the electronics industry.
Preparation
Preparation method: Polyvinyl chloride is chlorinated to obtain a high molecular compound. According to the degree of polymerization, it can be made into high viscosity, medium viscosity and low viscosity types. The high viscosity type has better counterfeit resistance, chemical corrosion resistance and elasticity. The low viscosity type is more soluble in vegetable oils. Powdered polyvinyl chloride is swollen with an appropriate solvent at a temperature below 50°C and then suspended in water for chlorination.
Solvent method
The solvent method is the earliest method used to prepare CPVC. The West German AG method company first used the solvent method for production. This process is relatively mature. Its main process is to dissolve the PVC resin in chloroform or carbon tetrachloride solvent and then chlorinate it. In this method, the concentration of PVC is very important. For example, when ethylene dichloride is used as a solvent, chlorination of a 12% (mass fraction, the same below) PVC solution will cause more dehydrochlorination and degradation, and the resulting CPVC contains approximately equal amounts of 1, 2-dichloroethylene and 1, 1, 2-trichloroethylene units. However, when a 7% ethylene dichloride solution of PVC is chlorinated, dehydrochlorination and degradation are less, and the chlorination of PVC is more uniform. CPVC is mainly composed of 1, 2-dichloroethylene units. It is reported that the use of a 1:1 (volume ratio) mixed solvent composed of ethylene dichloride and trichloroethylene can achieve uniform chlorination. PVC is soluble in chlorobenzene. Therefore, in the presence of initiator and promoter, PVC can also be chlorinated by reacting with chlorine in chlorobenzene at 110~115ºC. The initiator is usually azobisisobutyronitrile, and the promoter can be p-chlorobenzenethionamide dichloride.
The solvent method chlorination is relatively uniform, and the product has good solubility, which is very suitable for use as coatings, adhesives, etc. However, the product produced by this method has poor thermal stability and mechanical properties, and cannot be used to make hard products including pipes; at the same time, due to the use of organic solvents such as chloroform or carbon tetrachloride, which are highly toxic and difficult to recycle, it causes environmental pollution. This method is gradually being eliminated.
Suspension method
In the early 1960s, Goodrich Company in the United States first used the aqueous suspension method to produce CPVC. The process is to suspend powdered PVC resin in hydrogen chloride solution, pass chlorine in the presence of additives, and the chlorination reaction proceeds according to the free radical reaction mechanism. At this time, the chlorination conversion rate is controlled by diffusion. In order to facilitate the diffusion of chlorine in the polymer phase and improve the uniformity of chlorination, the early process required the addition of a swelling agent, such as chloroform or CCl4, to the water phase to increase the contact area between chlorine and PVC. Other researchers have found that when the raw material PVC is polymerized by vinyl chloride monomer in the presence of a special modifier, the uniformity of CPVC chlorination can be improved without adding a swelling agent, and the reaction rate can also be increased to enhance the processing performance of the product. After the preparation of CPVC is completed, an inert gas is introduced into the reaction system in time and a reducing agent is added. The reducing agent can prevent the hypochlorous acid generated by the reaction of Cl2 and H2O from reacting with CPVC to generate organic matter containing carbonyl and double bonds.
The suspension method has a simple production process, a short production process, good heat resistance and mechanical properties, and a low production cost. It is a method commonly used at home and abroad. Its disadvantage is that the acidic waste gas generated in the production process needs to be treated, and the product post-processing is cumbersome.
Gas-solid phase method
The gas-solid phase chlorination method was first reported by the West German company Laurent in 1958. The gas-solid phase chlorination method is to put the PVC resin in a dry state into a reactor or fluidized bed at normal pressure and directly carry out the chlorination reaction. The loose particles can be chlorinated by treating with diluted oxygen in a 55°C boiling bed. The gas flow can be composed of a mixed gas containing 50% chlorine (volume fraction), 0.75% fluorine (volume fraction) and 49.25% nitrogen (volume fraction). After 100 minutes of reaction, CPVC containing 64% chlorine (volume fraction) and 0.6% fluorine (volume fraction) can be obtained. Light energy catalyzes chlorination, but trace oxygen also has a catalytic effect when there is no light.
The process has a short production process, is easy to be continuous, has low investment, and does not produce waste acid and wastewater in the production process. There is basically no equipment corrosion, and the post-treatment is greatly simplified and has the advantages of light pollution to the environment. The uneven chlorination and difficulty in heat removal in the gas-solid phase chlorination method limit the industrialization of the process. The exploration and research on the solid phase chlorination device, reactor type, and reaction process conditions in the United States, Japan, Israel, Germany, and China mainly focus on solving these two problems.
Processing
Although CPVC is a polymer made from PVC and shares some properties with PVC, it is also a polymer with its own characteristics, which is particularly important for its processing. For example, the melting temperature of CPVC polymer ranges from 400°F to a maximum of 450°F. Chrome-plated or stainless steel dies are required for extrusion processing. The extrusion die must be well streamlined to ensure long-term processing and operation. Flat dies cannot achieve satisfactory extrusion operation time. In order to well control the extrusion size of pipes and profiles, it is best to use vacuum shaping technology. The extrusion equipment must be equipped with a screw drive of at least 40 horsepower. There are several screw designs that are suitable for extrusion processing of various well-formulated mixed materials.
Injection molding requires a low-compression screw with a suitable lead-out length. Materials for pipe fittings require a pointed plasticizing screw. Low viscosity, high output materials require a processing screw with the sliding check ring removed, and a ball check screw cannot be used. Injection molds should be made of stainless steel, or at least chrome-plated or nickel-plated.
){kind=link}