Chlorinated Polyethylene

1.Introduction:

Chlorinated Polyethylene is a high molecular polymer material made from HDPE through chlorination.The special molecular structure gives CPE many superior physical and chemical performances that makes CPE can be widely used in PVC, engineering plastics (CPE resin series )and Rubber applications (CM Rubber series).

As one of the most important impact modifier in the universal plastics market, CPE is widely used in processing of PVC extrusion and injection molding products ,including rigid PVC profile, pipes, pipe fittings,sheets and panels. It can greatly enhance the impact strength of the rigid PVC products and give the products an excellent low-temperature performance, excellent weather resistance. Some customers are also use it for formulations of PE or PP plastic products with proper amount.

Compared with other impact modifiers like AIM (Acrylic Impact Modifier), MBS and ABS, CPE is more competitive in its comprehensive performances and price.

CPE is favored by more and more customers and it is expanding to bigger share of the impact modifier market.

CPE is suitable for substitution of Acrylic impact modifier (AIM) or blending with Acrylic impact modifier (AIM) with a certain percentage without adjusting the processing data and the formulation, resulting in an optimum performance and cost-effective solution.

2. Appearance: White powder, non-toxic.

3.CPE molecular formula: CH2-CHCl-CH2-CH2]n, English abbreviation: CPE or CM

Chlorinated polyethylene (CPE) is a saturated polymer material.

4.Production technology: CPE is mainly produced by suspension method, which is divided into water phase method and hydrochloric acid phase method.

5.Product characteristics:

Because the CPE molecule does not contain double chains, it has good weather resistance,fire resistance, thermal stability is better than PVC, low cost and excellent performance.Soluble in aromatic hydrocarbons and halogenated hydrocarbons, insoluble in aliphatic hydrocarbons, decomposition above 170℃, release hydrogen chloride gas, it has a stable chemical structure, excellent aging resistance, fire resistance, cold resistance, weather resistance, free coloring, chemical resistance, ozone resistance and electrical insulation and good compatibility and processing. It can be mixed with PVC, PE, PS and rubber to improve its physical properties.Widely used in wire, cable, rubber hose, plastic hard products modification, ABS modification and magnetic materials, films. Soft products, sealing strips, waterproof coils and other industries.

1） good heat resistance: the softening temperature of vinyl resin increases with the increase of chlorine content, and the heat resistance also increases;

2） good processing performance: CPVC can be extruded, injected, calender and turning millingdrilling, etc., the product shrinkage is low;

3） good flame retardant performance: CPVC limit oxygen index is 60, poor combustion capacity,slow flame diffusion, and smoke suppression;

4）various installation forms: can be socket, welded, wire and flange installation, to meet theneeds of different occasions;

5） good mechanical properties: CPVC tensile strength, flexural strength and hardness are higherthan PVC, and has higher rigidity, but the impact performance is worse;

6)high dielectric performance: CPVC has good high temperature insulation, low dielectric loss;

7)excellent corrosion resistance: chlorinated polyvinyl chloride (CPVC) can resist acid, alkali,straight chain alkane and oil corrosion at high temperature;

8)high pressure performance: CPVC can resist greater pressure, and can withstand higherpressure after encapsulation enhancement.

6.Application Formula influence:

Addition amount(only for reference):

When the amount of addition is less than 10 dosages, the impact strength of PVC increases quickly with the addition of CPE, but the impact strength of PVC is little increased by further increasing the amount of CPE. Therefore, as an impact agent used, the amount of CPE added to 8-10 dosages is appropriate, and with the increase of CPE, the tensile strength of PVC blend continues to decline, the elongation at break increases, such as the product of tensile strength and elongation at break indicates its toughness, it is obvious that with the increase of the amount of CPE added PVC toughness will be significantly improved.

Some literature believes that when more than 8 dosages, CPE exceeds the saturationsolubility in PVC and precipitates from PVC, forming a microphase separation structure of PVC as a sea and CPE as an island, thus greatly improving the impact strength of PVC. Some literature also believes that CPE can form a network in the formula when more than 6 dosage, thus playing a role in impact modification. However, when CPE is added at a low amount (such as 1 dosages), it can neither form a network in the formula system nor exceed its saturation solubility in PVC and precipitate, and its impact modification effect in the formula is minimal.

Main application:

In the thermoplastic resin industry, in addition to being used alone, CPE can also be blendedwith polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), polystyrene (PS), ABSand other resins, and even polyurethane (PUR).

In the rubber industry, CM can be used as a high-performance, high-quality special rubber,and can also be blended with ethylene propylene rubber (EPR), butyl rubber (IIR), nitrile butadiene rubber (NBR), chlorosulfonated polyethylene (CSM) and other rubbers.

Chlorinated polyethylene can be used as a modifier of polyvinyl chloride, ABS and otherpolyolefin, which can improve the toughness of polyvinyl chloride and improve the printability and flame retardancy of ethylene, and is used in the manufacture of non-combustible andchemical resistant floor materials, artificial leather, plate and so on. It can be used to improve the toughness and flame retardancy of adhesives. It can also be used in the manufacture of foam, film, plate, laminate material, cable and wire cladding.

7.Processing properties:

When the number of CPE added is less than 5 dosages, it is delayed plasticization, and it has no effect on the plasticization of the formula system at 5 dosages. It plays a role in promoting plasticization when CPE exceeds 5 dosage. With the increase of CPE, the plasticization time of the formula becomes shorter and shorter, the maximum plasticization torque and balance torque increase, and the plasticization temperature gradually decreases.

CPE has a chlorine content of 35% and there are two chain segments in its structure: One isthe chlorination chain segment in which hydrogen atoms are replaced by chlorine atoms,which is structurally strong, similar to PVC, and has good compatibility. The other is the PE chain segment in which hydrogen atoms are not replaced by chlorine atoms, and the structural polarity of this segment is very weak, and the compatibility with PVC is poor, which plays an external lubrication role between PVC and can delay the plasticization of PVC. The glass conversion temperature of CPE is about 10℃, while PVC is 80℃. Under the test conditions, CPE shows a tendency to become soft plasticized earlier than PVC and has a slightly higher viscosity. When the amount of CPE is small, the total amount of polar segments with good compatibility between CPE and PVC is less, and the external lubrication of PE segment is dominant, delaying the plasticization of the system. With the increase of CPE, the advance softening and plasticizing of a large number of CPE molecules and higher viscosity promote the viscosity of the whole formula system. At this time, the influence of CPE on the viscosity of the whole material overcomes the external lubrication of the PE chain segment in its structure, so that the whole formula system starts plasticizing at a lower temperature, which promotes the plasticization of the material. The addition of low-component CPE can delay plasticization, which has been applied in actual production. In the promotion of ACR, because the viscosity of the ACR impact modified formula system is greater than that of CPE, the plasticization time is shorter, and the plasticization torque is higher, there are some problems in directly replacing CPE with ACR, so a small amount of CPE is used in the use of ACR impact system to delay plasticization. To a certain extent, the shortcomings of ACR formula plasticizing too fast are alleviated, which is better than the complete application of lubricants to adjust the plasticizing behavior.