1. Small Nasdaq continuous futures: polyvinyl chloride (PVC), an important organic synthetic material in China. Its products have good physical and chemical properties and are widely used in industry, construction, agriculture, daily life, packaging, electricity, public utilities and other fields. In terms of product classification, PVC belongs to synthetic resins among the three major synthetic materials, including five general resins, namely polyethylene PE, polyvinyl chloride PVC, polypropylene PP, polystyrene PS and ABS resin. Introduction of PVC PVC is a nontoxic and odorless white powder. High chemical stability and good plasticity. Except for a few organic solvents, it can resist any concentration of hydrochloric acid, sulfuric acid below 90%, nitric acid below 50-60% and caustic soda below 20% at room temperature, and it is also quite stable to salts. PVC has poor thermal stability and light resistance. Hydrogen chloride (HCl) gas can be decomposed and released above 140℃, resulting in discoloration of PVC. Excellent electrical insulation, generally non-combustible, can burn on the flame and release HCl, but it will extinguish itself when leaving the flame, so it is a "self-extinguishing" and "flame retardant" substance. Mainly used in the production of transparent films, pipe fittings, gold cards, blood transfusion equipment, soft and hard pipes, plates, doors and windows, profiled materials, films, electrical insulation materials, cable sheaths, blood transfusion materials, etc. Polyvinyl chloride is formed by free radical polymerization of vinyl chloride monomer, and the polymerization degree n is generally in the range of 500~20000.
2. Linear low density polyethylene (LLDPE) is a kind of * * polymer which is polymerized by ethylene and a small amount of higher α-olefins (such as butene-1, hexene-1, octene-1, tetramethylpentene-1, etc.). ) Under the action of catalyst. However, according to ASTM D- 1248-84, the density range of 0.926 ~ 0.940g/cm3 belongs to medium density polyethylene (MDPE). The new generation LLDPE extends its density to plastic (0.890 ~ 0.9 1.5g/cm3) and elastomer (