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What are the terms in the polyurethane industry?


1. Hydroxyl value: the amount of hydroxyl (- OH) in 1 g polymer polyol is equivalent to the milligram number of KOH, per unit mgKOH/g. 

2. Equivalent: equivalent = 56100 / hydroxyl value. 

3. Isocyanate content: 

4. Isocyanate index: indicates the extent of excess isocyanate in polyurethane formulations, usually expressed by the letter R. 

5. Chain extender: refers to low molecular weight alcohols and amines that can extend, expand or form spatial reticular cross-linking of molecular chains. 

6. Hard segment: the chain segment formed by the reaction of isocyanate, chain extender and cross-linking agent on the main chain of polyurethane molecule, these groups have large cohesion energy, large space volume and large rigidity. 

7. Soft segment: carbon main chain polymer polyol has good compliance and is a flexible segment in the main chain of polyurethane foaming machine. 

8. Foaming index: the number of parts of water used in 100 parts of polyether is defined as the foaming index (IF). 

9. One-step method: refers to the method of curing at a certain temperature by mixing oligomer polyol, diisocyanate, chain extender and catalyst directly into the mold at a certain temperature. 

10. Prepolymer method: firstly, the oligomer polyol was prepolymerized with diisocyanate to form polyurethane prepolymer with NCO group, and then the prepolymer was reacted with chain extender to prepare polyurethane elastomer, which is called prepolymer method. 

11. Semi-prepolymer method: the difference between semi-prepolymer method and prepolymer method is that part of polyester polyol or polyether polyol is added to the prepolymer in the form of mixture with chain extender and catalyst. 

12. Reactive injection molding: also known as reactive injection molding, RIM (Reaction Injection Moulding), is measured in liquid form by oligomers with small molecular weight, mixed instantly and injected into the mold at the same time, and reacts rapidly in the mold cavity, resulting in a rapid increase in the molecular weight of the material. 

The process of producing a new polymer with a new characteristic group structure at an extremely fast rate. 

13. Foaming index: that is, the number of parts of water used in 100 parts of polyether is defined as the foaming index (IF). 

14. Foaming reaction: generally refers to the reaction of water with isocyanate to form substituted urea and release CO2. 

15. Gel reaction: generally refers to the formation of carbamate. 

16. Gel time: the time required for a liquid substance to form a gel under certain conditions. 

17. Milk white time: at the end of area I, the milky white phenomenon appears in the mixed material of liquid phase insulation geothermal polyurethane foaming machine. 

This time is called (cream time) in the formation of polyurethane foam. 

18. Chain extension coefficient: refers to the ratio of the amount of amino and hydroxyl groups (unit: mo1) in the chain extender component (including mixed chain extender) to the amount of NCO in the prepolymer, that is, the molar number (equivalent number) ratio of active hydrogen group to NCO. 

19. Low unsaturated polyether: mainly for PTMG development, the price of PPG, unsaturation reduced to 0.05 mol / kg, close to the performance of PTMG, using DMC catalyst, the main variety of Bayer Acclaim series products. 

20. Ammonia grade solvents: 

21. Physical foaming agent: a physical foaming agent is a foam pore formed by the change of the physical form of a substance, that is, by the expansion of a compressed gas, the volatilization of a liquid, or the dissolution of a solid. 

22. Chemical blowing agent: chemical foaming agent is a compound that can release gases such as carbon dioxide and nitrogen after heating and decompose, and form fine pores in the composition of the polymer. 

23. Physical crosslinking: there are some hard chains in polymer soft chains, which have the same physical properties as chemically crosslinked vulcanized rubber at temperatures below softening point or melting point. 

24. Chemical crosslinking: a process in which macromolecular chains are linked by chemical bonds to form reticular or body-shaped polymers under the action of light, heat, high energy radiation, mechanical force, ultrasonic wave and cross-linking agent.

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Fuleite Mechanical and Electrical Technology Co., Ltd. 

Mobile phone: 18933370499

E-mail: fuleitejd@163.com

Web site: www.puflt.com

Add: Hongjian Industrial Park, Shenghui North Industrial Zone, Nantou Town, Zhongshan City, Guangdong Province. 34 Tongji west road