CPE is chlorinated polyethylene, which is obtained by chlorination of special high-density polyethylene (HDPE), that is, product of partially replacing hydrogen atoms on molecular chain of HDPE with chlorine atoms. After drying, it is white powder and non-toxic.

 

Because CPE molecule does not contain double chains, it has good weather resistance, and at the same time, it has flame resistance and thermal stability better than PVC, low cost and excellent performance. Soluble in aromatic hydrocarbons and halogenated hydrocarbons, insoluble in aliphatic hydrocarbons, decomposes above 170 ℃, emits hydrogen chloride gas, which has a stable chemical structure, excellent aging resistance, flame resistance, cold resistance, weather resistance, free coloring, chemical resistance, ozone resistance and electrical insulation, as well as good compatibility and processability, can be blended with PVC, PE, PS and rubber to improve their physical properties.

First: type of PE used ----- CPE obtained from high molecular weight polyethylene has higher viscosity and tensile strength, but adhesion between this CPE and PVC resin is low, and low molecular weight polyethylene is obtained. Viscosity and tensile strength of CPE are low, and CPE obtained by using high-density polyethylene has good thermal resistance.
Second: size of raw material particles-----when particle size is too small, it is easy to form jelly or agglomerate CPE. When particle size is too large, distribution of chlorine is uneven, and it is difficult to dissolve in organic solvents. Optimal particle size range is 0.1-200 μm.
Third: level of chlorination of CPE-----When chlorine content is below 25%, it has poor compatibility with PVC and cannot be used as a modifier; when chlorine content is greater than 40%, it has good compatibility with PVC and can be used as a solid plasticizer, but is not suitable for impact modifiers; CPE with a chlorine content of 36-38% has good elasticity and compatibility with PVC, so it is widely used as a PVC impact modifier. CPE with chlorine content of 35% is currently used the most. CPE with chlorine content of about 35% has low crystallinity and glass transition temperature, has good rubber elasticity, has suitable compatibility with PVC, and is widely used as impact modifier for rigid PVC products.

 

CPE is mainly produced by suspension method, which is further divided into aqueous phase method and hydrochloric acid phase method. Chlorine utilization rate of aqueous phase method is high, and chlorine content of product is stable, but equipment is seriously corroded and three wastes are large. Hydrochloric acid phase method is the most advanced production method, with short process, stable product quality and low three wastes.

 

1. Application of CPE-enhanced PVC waterproofing membrane in waterproofing membrane, due to excellent characteristics of CPE, tensile strength of new product has been increased by 80%, tear strength has been increased by 50%, its mechanical weather resistance, low temperature resistance, aging resistance and other properties have been improved. It is very popular in construction sector (where CPE is added at 10%-15%). Neoprene CPE waterproofing membrane and neoprene CPE styrene-butadiene rubber waterproofing membrane have advantages of high strength, high elasticity, high elongation, corrosion resistance, high temperature resistance, cold resistance, aging resistance, flame retardant, etc. They are a new generation of ideal waterproof materials and have a broad market.
2. Use of CPE and PVC to produce plastic doors and windows greatly improves its elasticity, toughness and low temperature performance, and has good weather resistance, heat resistance and chemical stability. This kind of plastic doors and windows is cheap, corrosion-resistant, has various and bright colors. It has outstanding advantages over aluminum alloy doors and windows. It has replaced aluminum doors and windows to a large extent, market will become more and more broad.
3. Application in wire and cable sheath: Addition of CPE can improve its cathodic combustion performance, anti-aging performance and physical and mechanical properties, CPE can also be used as main body to make wire and cable covering materials, and its performance is excellent.
4. Incorporating CPE elastomer into PE can improve its printability, flame resistance and flexibility. After adding 5% CPE to HDPE, adhesion of resulting mixture to ink increased threefold. After adding CPE to mining PE hose, it has better flame retardant properties.
5. Application of CPE as main material: it can manufacture hoses with good oil resistance, acid resistance, folding resistance, ozone resistance and freon resistance, suitable for manufacture of hydraulic hoses, cooler hoses, fuel hoses, etc. Imitation cowhide sole made of CPE as main body has excellent performance.
6. Application of CPE in transmission belts: It can manufacture heat-resistant transmission belts, and at the same time has good resistance to non-polar solvent swelling. Adhesion and flexion times of each tape layer of transmission belt produced by using CPE/NR/SBR combined rubber are higher than those of transmission belt made of pure rubber, thus prolongs service life, also improves process properties of pure rubber compound, such as large shrinkage after calendering, poor permeability of rubber compound in textile after calendering, and easy bonding of forming belt embryo, improves weather resistance and flame retardancy of transmission belt.
7. CPE and other rubbers are used together: CPE has good compatibility with various rubbers. CPE and NR are blended, its wear resistance, fatigue resistance, acid and alkali resistance are improved, and price is lower than that of NBR and CR. Combination of CPR and NBR has improved oil resistance and excellent thermal oxygen aging performance. It can be used to manufacture oil-resistant rubber hoses and oil-resistant sealing products.
5. Models and main uses of CPE: