Applications: microwave dishes, pots, plastic buckets, thermos shells, woven bags, etc..
Properties: high chemical stability, good hygiene performance, high heat resistance. Microwave oven tableware can be used marked PP plastic products.
Toxicity: non-toxic, harmless to the human body.
The polymer can have three three-dimensional structure: isometric, intergraphic, atactic polypropylene, the first two can crystallize, the latter can not. Commercially available polypropylene products are basically the structure of the market iso-gauge, melting point of 164 ~ 170 degrees Celsius, the crystalline part of the density of 0.935 grams / cubic centimetre, the non-clean part of 0.851 grams / cubic centimetre.
PP's biggest drawback is that it is easy to oxidize and age. Now with the addition of antioxidants and ultraviolet absorbers to overcome.
Polyvinyl chloride (PVC)
Applications: cling film, plastic shoes and leather products, film, cable, plastic bags.
Properties: hard plastic, commonly used in industry.
Toxicity: made into plastic wrap, plastic bags and other soft plastics, must be added to a large number of auxiliary materials, some of which are toxic, the release of harmful substances in this material may cause cancer.
Density 1.4 g / cm3, melting temperature of 120 ~ 210 degrees Celsius, insoluble in general organic solvents such as hydrocarbons, alcohols and esters, etc., can be dissolved in tetrahydrofuran, methyl ethyl ketone, cyclopentyl ketone, nitrobenzene, dimethyl sulfoxide, etc., has a good resistance to acids and alkalis.
Polystyrene (PS)
Applications: disposable plastic tableware, combs, boxes, ballpoint pen sticks, children's toys, plastic shopping bags.
Properties: high transparency, glossy surface.
Toxicity: the material itself is non-toxic. The production of disposable tableware will use a large number of heavy metals and other prohibited additives, and food contained in water, vinegar, oil and other mutual dissolution, into the human body, may cause indigestion, local pain, and liver system lesions and other diseases, affecting the intellectual development of children, and in severe cases will lead to gallstones, heavy metal poisoning and even cell cancer. If the tableware contains industrial paraffin, it may even cause cancer.