Structure characteristics and application of CPE

1, chlorinated polyethylene, the full English name is chlorinated polyethylene, short for cpe. Chlorinated polyethylene cpe is a material obtained by the partial replacement of hydrogen atoms by chlorine atoms on high-density polyethylene hdpe. The appearance of cpe is white powder, non-toxic and tasteless.

2, the chlorinated polyethylene made with low pressure polyethylene hdpe, its high temperature thermal aging resistance than the chlorinated polyethylene made with high pressure polyethylene is better. It is generally used to manufacture chlorinated polyethylene with a density of 0.93 ~ 0.96g/cm3, an average molecular weight of 5 ~ 250,000, and a melting index of 0.01 ~ 2.0g/10min. The degree of chlorination of chlorinated polyethylene has great influence on its properties. When the chlorine content is less than 15%, it is plastic; When the chlorine content is 16-24%, it is a thermoplastic elastomer. It is a rubbery elastomer with a chlorine content between 25 and 48%. When the chlorine content is 49-58%, it is a leather-like semi-elastic hard polymer. When the chlorine content is as high as 73%, it becomes a brittle resin. When about 27% of chlorine is introduced into high-pressure polyethylene, the crystallization will completely disappear, and when about 30% of chlorine is introduced into low-pressure polyethylene with higher crystallinity, the crystallization will also completely disappear. As a rubber elastomer, the chlorine content is best in the range of 30 to 40%. At present, the chlorine content of commercial chlorinated polyethylene rubber is mostly in the range of 25 ~ 45%. Generally, when the chlorine content increases, the oil resistance, gas permeability resistance and flame retardant become better; Cold resistance, resilience and compressive bending resistance are better when chlorine content is reduced.

3. Characteristics of chlorinated polyethylene cpe

1) cpe is a kind of saturated rubber, with excellent heat resistance to oxygen aging, ozone aging, acid and alkali resistance, chemical properties.

2) cpe has excellent oil resistance, including excellent resistance to astm 1 oil and astm 2 oil, which is comparable to nbr; Excellent resistance to astm 3 oil, better than cr, and comparable to csm.

3) cpe contains chlorine, has excellent flame retardant performance, and has combustion anti-drip characteristics. The flame retardant material with good flame retardant performance and low cost can be obtained by the appropriate proportion of antimony flame retardant, chlorinated paraffin and al(oh)3.

4) cpe is non-toxic, does not contain heavy metals and pahs, and fully meets environmental requirements.

5) cpe has high filling performance and can be prepared to meet a variety of different performance requirements. cpe has good processing properties and Mooney viscosity (ml121 1+4) is available in a variety of grades between 50-100.

4, chlorinated polyethylene can be divided into resin type chlorinated polyethylene (cpe) and elastic type chlorinated polyethylene (cm) two categories. In addition to being used alone, it can also be blended with polyvinyl chloride (pvc), polyethylene (pe), polypropylene (pp), polystyrene (ps), abs and other resins, and even polyurethane (pu). In the rubber industry, cpe 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. Mainly used in: wire and cable (coal mine cable, ul and vde and other standards specified in the wire), hydraulic hose, automotive hose, tape, rubber plate, pvc profile pipe modification, magnetic materials, abs modification, etc.

5, cpe reinforcers are mainly carbon black and white carbon black; The main filling systems are calcium carbonate, clay and talc powder, etc. The plasticizers mainly include doa and dos. The stabilizers commonly used in cpe vulcanization are mainly sodium hard acid, magnesium oxide, barium stearate and lead sulfate tribasic, etc., mainly absorbing hydrogen chloride produced during vulcanization.

6. cpe is saturated rubber, and the general sulfur vulcanization system can not effectively vulcanize it. The vulcanization system is divided into four major vulcanization systems: thiourea system, peroxy system, thiadiazole system and triazole dimercapto amine salt system.