Can PP, PE, and PVC plastic storage tanks withstand benzene? ? Room temperature

Chemical and physical properties of P material: P is a semicrystalline material. It is harder than PE and has a higher melting point. Since homopolymer PP becomes very brittle when the temperature is above 0°C, many commercial PP materials are random copolymers containing 1–4% ethylene or block copolymers with a higher proportion of ethylene. Polymer-type PP materials have a lower heat distortion temperature (100°C), low transparency, low gloss, and low rigidity, but they possess greater impact strength. The strength of PP increases as the ethylene content increases. The Vicat softening temperature of PP is 150°C. Due to its high crystallinity, this material has excellent surface stiffness and scratch resistance. PP does not have the problem of environmental stress cracking. Typically, PP is modified by adding glass fibers, metal additives, or thermoplastic rubbers. The flow rate MFR of PP ranges from 1 to 40. PP materials with low MFR have good impact resistance but lower ductility. For materials with the same MFR, the strength of the copolymer type is higher than that of the homopolymer type. Due to crystallization, PP has a relatively high shrinkage rate, generally ranging from 1.8 to 2.5%. Moreover, the uniformity of the shrinkage rate direction is much better than that of materials such as PE-HD. Adding 30% glass additive can reduce the shrinkage rate to 0.7%. Both homopolymer and copolymer types of PP materials possess excellent resistance to moisture absorption, acid and alkali corrosion, as well as solubility. However, it has no resistance to aromatic hydrocarbon solvents (such as benzene) or chlorinated hydrocarbon solvents (such as carbon tetrachloride). PP also does not possess antioxidant properties at high temperatures like PE. Toluene has a significant corrosive effect on equipment and fittings made of all plastic materials at high temperatures; it can dissolve them in a short time. In production, if toluene is used as a solvent, PP pipes are generally not employed. I have personally seen PP pipes get corroded and damaged by toluene

PP (polypropylene) can resist corrosion at room temperature, but it is not resistant to benzene at high temperatures; it cannot withstand such conditions at levels of 60–100°C. Even at room temperature, benzene or toluene can have a slight corrosive effect on PP, so its use over long periods is not recommended. PE can be divided into three main categories: high-pressure low-density polyethylene (LDPE), high-density polyethylene (HDPE), and linear low-density polyethylene (LLDPE). PE composite pipes are both corrosion-resistant and resistant to peeling; PVC is not resistant to benzene.