The difference between PU and TPR material:
TPR (thermoplastic polyurethane elastomer) is an emerging plastic product. Due to its good processability, weather resistance and environmental protection, TPU is widely used in shoe materials, pipes, films, rollers, cables, and wires. Polyurethane thermoplastic elastomer, also known as thermoplastic polyurethane rubber, referred to as TPU, is an (AB) n-block linear polymer, A is a high molecular weight (1000-6000) polyester or polyether, B is 2-12 straight The diol of the chain carbon atom, the chemical structure between the AB segments is linked with a diisocyanate, usually an MDI. The general structural formula is shown in the figure. Thermoplastic polyurethane rubbers are crosslinked by intermolecular hydrogen bonds or lightly crosslinked between macromolecular chains, and the two crosslinked structures are reversible with increasing or decreasing temperature. In the molten state or the solution state, the intermolecular force is weakened, and after cooling or solvent evaporation, strong intermolecular forces are connected together to restore the properties of the original solid.
Polyurethane thermoplastic elastomers are of the polyester type and the polyether type, white irregular spherical or columnar particles, the relative density of 1.10 to 1.25, and the polyether type relative density is smaller than the polyester type. The polyether type glass transition temperature is 100.6-106.1 ° C, and the polyester type glass transition temperature is 108.9-122.8 ° C. The polyether type and polyester type have a brittleness temperature lower than -62 ° C, and the hard ether type has low-temperature resistance which is worried about the polyester type.
The polyurethane thermoplastic elastomer is characterized by excellent wear resistance, excellent ozone resistance, high hardness, high strength, good elasticity, low-temperature resistance, good oil resistance, chemical resistance, and environmental resistance. Polyether in moist environment The ester hydrolysis stability of the ester type far exceeds that of the polyester type.
Polyurethane thermoplastic elastomer is non-toxic, odorless, soluble in solvents such as methyl bromide, cyclohexanone, tetrahydrofuran, dioxane, dimethylformamide, etc., and soluble in toluene, ethyl acetate, methyl ethyl ketone, acetone, etc. In the mixed solvent of proportional composition, it exhibits a colorless and transparent state and has good storage stability.
PU polyurethane is a general term for a polymer compound formed by reacting a diisocyanate or a polyisocyanate with a compound having two or more hydroxyl groups, and has a plurality of repeating NHCOO groups in its main chain. Commonly used diisocyanates are toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), multi-Asia Methyl polyphenyl polyisocyanate (PAPI), benzene dimethylene diisocyanate (XDI), and the like. Depending on the hydroxyl component used, it can be classified into two types, polyester type, and polyether type. Can be used in the manufacture of plastic products, wear-resistant synthetic rubber products, synthetic fibers, rigid and flexible foam products, adhesives and coatings.
PU sandals cleaning:
1. When cleaning, you can directly wash the grease stains with detergent. If it is not black, red and other dark color fabrics can be lightly brushed with detergent powder;
2. The pure white fabric can be removed with a thinner bleach (1:10 dilution) directly with a toothbrush brush, can be removed;
3. Soak with detergent for 10 minutes (add 6 drops of detergent in each pot of water, stir evenly), and then routinely;
4. Dilute with oxalic acid before washing, wipe the contaminated area with a toothbrush, and then routinely use a toothpaste or detergent to brush with a toothbrush several times, then rinse with water and dry;
5. Accidentally let the bag stained with oil, first wipe the oil with a soft cloth, and then wipe again with the cleaning solution, be gentle;
6. When there is more dirt, use a cleaning paste to wipe it, which can achieve a completely new effect. After cleaning, you must wipe it carefully with a dry cloth.