Polyurethane board refers to the polyurethane sandwich board made entirely of PU or composed of PU and color steel plate. It is mainly used for the external thermal insulation system of industrial and civil buildings, and has become the most widely used product system of PU.
Polyurethane (PUR) refers to a large class of polymers that contain many carbamate group characteristic structures in the molecular backbone. It is a polymer material between plastic and rubber. It has a large elongation, a wide range of hardness, a wide range of formula adjustment, and excellent wear resistance and mechanical properties. Pourable polyurethane elastomer (CPUR) is the most important of the three processing types of polyurethane elastomer, accounting for 60% of the PUR. It has the advantages of diversified chemical structure, easy adjustment of viscosity, excellent processing technology, easy to put into industrial production, convenient use and fast curing, so it is very suitable for manufacturing large and complex components. Polyurethane wear-resistant lining plate is produced and processed by casting polyurethane elastomer process. Polyurethane is a kind of polymer with urethane type repeating structural unit in the macromolecular chain, which is fully called polyamino acid ester and polyurethane in English, referred to as PU or PUR for short. PU is the product of polyisocyanate and polyether or polyester polyol in a certain proportion.
Performance of PU elastomer: The performance of PU elastomer is slightly different from that of PU elastomer synthesized by plastic polyol. Polyester PU has high mechanical properties, good oil resistance, but poor water resistance; The low temperature resistance and hydrolysis resistance of polyether PU are better than those of polyester PU, but the oil resistance and mechanical properties are slightly worse.
Mechanical properties of PU: PU elastomer has a wide range of hardness changes, ranging from Shore A10 to D80, and its elongation at break is up to 600%~800%. However, the highest Shore hardness of natural rubber is only A70, and the elongation at break is 550%. The tear strength of PU elastomer is high, 2~5 times greater than that of natural rubber. PU elastomer has high resilience and good shock absorption effect. PU elastomer has good wear resistance, 3~10 times that of natural rubber.
1. Wide hardness range. It still has the elongation and resilience of rubber under high hardness. The hardness range of polyurethane board is Shore A10-D80.
2. High strength. Their tensile strength, tear strength and bearing capacity are much higher than those of general rubber under the hardness of rubber. At high hardness, its impact strength and bending strength are much higher than those of plastics.
3. Wear-resistant. Its wear resistance is excellent, generally within the range of 0.01-0.10 (cm3)/1.61km, about 3-5 times that of rubber.
4. Oil resistant. Polyurethane plate is a kind of strong polar polymer compound, which has little affinity with non-polar mineral oil and is hardly corroded in fuel oil and mechanical oil.
5. Good resistance to oxygen and ozone.
6. Excellent vibration absorption performance can be used for vibration reduction and cushioning. In the mold manufacturing industry, it replaces rubber and spring.
7. It has good low-temperature performance.
8. Radiation resistance. Polyurethane has good resistance to high-energy radiation, and still has satisfactory performance at 10-10 Ge radiation dose.
9. It has good machinability. (Turning, milling, grinding and drilling are all available)