The difference between TPU and Pu
The difference between TPU and Pu
TPU (thermoplastic polyurethane elastomer) is a new type of plastic. Because of its good processability, weatherability and environmental protection, TPU is widely used in shoe materials, pipes, films, rollers, cables and wires and other related industries.Polyurethane thermoplastic elastomer, also known as thermoplastic polyurethane rubber, or TPU for short, is a (AB) n-type block linear polymer, a is a high molecular weight (1000-6000) polyester or polyether, B is a glycol containing 2-12 straight chain carbon atoms, and the chemical structure between ab chains is diisocyanate, usually MDI connection.
Thermoplastic polyurethane rubber is crosslinked by intermolecular hydrogen bond or slightly by macromolecular chain. With the increase or decrease of temperature, the two crosslinking structures are reversible. In the melting or solution state, the intermolecular force weakens, but after cooling or solvent volatilization, there is strong intermolecular force connected together to restore the original solid performance.
There are two types of polyurethane thermoplastic elastomer: polyester type and polyether type. The white irregular spherical or columnar particles have a relative density of 1.10-1.25. The polyether type has a smaller relative density than polyester type. The glass transition temperature of polyether type is 100.6-106.1 ℃, and that of polyester type is 108.9-122.8 ℃. The brittleness temperature of polyether type and polyester type is lower than - 62 ℃, and the low temperature resistance of hard ether type is less than that of polyester type.
The outstanding characteristics of polyurethane thermoplastic elastomer are excellent wear resistance, excellent ozone resistance, high hardness, high strength, good elasticity, low temperature resistance, good oil resistance, chemical resistance and environmental resistance. The hydrolysis stability of polyether ester in wet environment is far higher than that of polyester.
Polyurethane thermoplastic elastomer is nontoxic and tasteless, and it can be soluble in solvents such as A-B, cyclohexanone, tetrahydrofuran, dioxane, dimethylformamide, etc. it can also be soluble in mixed solvents composed of toluene, ethyl acetate, butanone and acetone in proper proportion, showing colorless and transparent state, with good storage stability.
Pu (polyurethane)
PU polyurethane is a general term of high molecular compounds formed by the reaction of diisocyanate or polyisocyanate and compounds with more than two hydroxyl groups. Its main chain contains many repeated nhcoo groups. The commonly used diisocyanates are toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (hmdi), polymethylidene polyphenyl diisocyanate (Papi), phenylmethylene diisocyanate (XDI), etc.
According to the different hydroxyl components, it can be divided into polyester type and polyether type. It can be used for manufacturing plastic products, wear-resistant synthetic rubber products, synthetic fibers, hard and soft foam plastic products, adhesives and coatings.
TPU and Pu are essentially composed of the same material. But in making these two kinds of rubber. They don't use the same formula. These two kinds of rubber are divided into many properties. The characteristics of the compound made from different formula are not the same. These characteristics refer to mechanical and physical characteristics.
