What is polyether polyol
Polyether polyols are oligomers containing ether bonds (-ROR-) in the molecule and OH groups at the end groups. It is made of a low-molecular compound containing active hydrogen, such as (alcohol rutin), as an initiator, and undergoes ring-opening polymerization with a compound containing an epoxy structure under the action of a catalyst. Polyether polyol is an important chemical raw material, and its biggest use is to synthesize polyurethane (PU) resin products, such as polyurethane foam, polyurethane adhesive, polyurethane adhesive, polyurethane elastomer, etc. In addition, it can also be used as a nonionic surfactant, lubricant, liquid fluid, heat exchange fluid, etc.
Polyether polyol is the main raw material for the production of polyurethane household products. Polyether polyols can be classified into two types. One is a polymer with polyol or organic amine as the initiator and propylene oxide (PO) (or propylene oxide and ethylene oxide), commonly known as PPG (polyethylene oxide). Ether polyol), this product is used in the largest amount in PU, and the other is polymer polyol, which is based on PPG, and then uses vinyl monomers, such as acrylonitrile (AN) or styrene (SN), etc. It is produced by bulk polymerization of polyols, called POP (polymer polyether polyol). POP is not used alone, but used in conjunction with PPG, which can significantly improve the hardness of flexible polyurethane foam and increase its bearing capacity. Used in the manufacture of high load-bearing polyurethane foams.
According to the use, polyether polyols can be divided into rigid foam, soft foam, CASE, POP and characteristic polyether.
1. Polyurethane rigid foam: synthesized from polymerized MDI and rigid foam PPG.
Rigid polyurethane foam, referred to as rigid polyurethane foam, is second only to soft polyurethane foam in the amount of polyurethane products. Polyurethane rigid foam mostly has a closed-cell structure, which has excellent characteristics such as good heat insulation effect, light weight, high specific strength, and convenient construction. It also has the characteristics of sound insulation, shockproof, electrical insulation, heat resistance, cold resistance, and solvent resistance. It is widely used in Insulation materials for refrigerators and freezers, cold storage, refrigerated trucks and other insulation materials, buildings, storage tanks and pipeline insulation materials, a small amount is used in non-insulation occasions, such as imitation wood, packaging materials, etc. Generally speaking, lower density polyurethane rigid foam is mainly used as heat insulation (insulation) material, and higher density polyurethane rigid foam can be used as structural material (imitation wood).
Polyurethane rigid foam is generally room temperature foaming, and the molding process is relatively simple. According to the degree of construction mechanization, it can be divided into manual foaming and mechanical foaming; according to the pressure of foaming, it can be divided into high-pressure foaming and low-pressure foaming; according to the molding method, it can be divided into pouring foaming and spraying foaming.
The main uses of polyurethane rigid foam are as follows:
a) Refrigeration and refrigeration equipment in food and other industries: such as refrigerators, freezers, cold storage, refrigerated trucks, etc. Polyurethane rigid foam is the most ideal insulation material for refrigeration and refrigeration equipment.
b) Industrial equipment insulation: such as storage tanks, pipelines, etc.
c) Building materials: In developed countries in Europe and the United States, rigid polyurethane foam for construction accounts for about half of the total consumption of rigid foam, which is more than double the amount of rigid foam used in refrigerators and freezers; in China, the application of rigid foam in the construction industry is not as good as in the West It is as common in developed countries, so the potential for development is very large.
d) Transportation industry: such as car roof, interior parts, etc.
e) Imitation wood: High-density (density 300~700kg/m3) polyurethane rigid foam or glass fiber reinforced rigid foam is a structural foam plastic, also known as imitation wood, with high strength, good toughness, dense and tough crust, simple molding process, and high production efficiency. High-grade features, higher strength than natural wood, lower density than natural wood, can replace wood for various high-end products.
1. Polyurethane soft foam: synthesized by TDI and soft foam PPG
Flexible polyurethane foam, referred to as polyurethane soft foam, is a kind of flexible polyurethane foam with certain elasticity. It is the most widely used polyurethane product in polyurethane products. Polyurethane soft foam mostly has an open-cell structure, which has low density, good elastic recovery, sound absorption, breathability, heat preservation and other properties. It is mainly used as cushion materials for furniture, mattresses, and vehicle seat cushions. Soft foam is used as filter material, sound insulation material, shockproof material, decoration material, packaging material and heat insulation material, etc. According to the degree of softness and hardness, that is, the difference in load resistance performance, polyurethane soft foam can be divided into ordinary soft foam, super soft foam, high-load soft foam, high-resilience soft foam, etc. Among them, high-resilience soft foam and high-load soft foam are generally Used in the manufacture of seat cushions and mattresses. According to different production processes, polyurethane soft foam can be divided into block soft foam and molded soft foam. Block soft foam is a foam product that is produced by a continuous process to produce a large volume of foam and then cut into the desired shape. Molded soft foam Foam is a foam product in which raw materials are directly mixed and injected into a mold to form a desired shape through the gap method.
The main uses of polyurethane soft foam include the following aspects:
Cushion material: such as seats, sofas, mattresses, etc., polyurethane soft foam is a very ideal cushion material, and cushion material is also the application field with the largest amount of soft foam
Sound-absorbing material: Open-cell polyurethane soft foam has good sound-absorbing and shock-absorbing functions, and can be used as indoor sound-insulating material.
Textile Composites: Toys, etc.
CASE: Polyols for clothing coatings, adhesives, sealants and elastomers are referred to as CASE
POP polymer polyol POP
Vinyl polymer grafted polyether polyol is commonly known as "polymer polyol" ( Polyether Polyol) , referred to as polymer polyol ( POP ), also known as white polyether polymer polyol, is a polymer-polyether dispersion, It belongs to organically filled polyether polyol, which is used to prepare high-load or high-modulus soft and semi-rigid polyurethane foam products. Its appearance is generally white or light milky yellow. It is based on general-purpose polyether polyol (generally general-purpose soft foam polyether triol, high-activity polyether), plus acrylonitrile, styrene, methyl methacrylate , Vinyl acetate, vinyl chloride and other vinyl monomers and initiators, carried out free radical grafting polymerization at about 100 degrees under the protection of nitrogen. Polymer polyol is a kind of polyol containing organic filler, which can replace inorganic filler, not only can make polyurethane foam have higher bearing capacity and good resilience performance, but also improve the cell structure and physical and mechanical properties of foam , is an important category of polyols for molding and block soft and semi-rigid polyurethane foams. The common ones are POP2045 and POP3628.
In terms of downstream product structure, although the consumption of polyurethane rigid foam is much lower than that of soft foam, in the next few years, with the promotion and application of polyurethane rigid foam in building energy conservation, polyurethane rigid foam will still maintain a relatively high growth rate. About 56% of domestic polyurethane rigid foam is used in refrigerators, freezers and cold storage areas, and 25% is used in the construction industry. At the same time, rigid foam insulation materials will be a potential development direction in the future. Secondly, the competition in the domestic hard foam market is becoming more and more fierce, and reducing costs will undoubtedly have a huge competitive advantage. at present, More popular is to use cheap vegetable oils to synthesize polyether polyols. In addition, low thermal conductivity is also a very important indicator of rigid polyurethane foam. GNE - 410 and GNE - 400 of Shanghai Gaoqiao Petrochemical Co. , Ltd. use toluenediamine as the starting agent. The polyurethane foam produced from this raw material has a very delicate cell structure and low thermal conductivity, and can be used in various occasions with strict heat insulation requirements.
on the contrary, Due to the slowdown in the growth of the ordinary soft foam market, the market demand for ordinary soft foam polyether is not optimistic. Due to the irrational product structure in our country. Hard foam ( foreign 3O % ~ 40 % ) , flexible foam, high resilience foam and CASE ( general term for coatings, adhesives, sealants, elastomers, The unreasonable ratio of foreign polyether polyols such as 30 % ) has resulted in the production focus of domestic manufacturers being basically the same, making the general soft foam market fiercely competitive under the drive of TDI and other raw material price increases. At present, domestic soft foam suppliers Margins are thinner. In the future, the growth point of polyether demand will be reflected in the automotive industry in terms of soft foam polyether.
Polymer polyol (POP) is a modified graft polyether polyol, which is a new type of raw material for the production of polyurethane foam. It has the ability to improve the load-bearing capacity and foam opening of polyurethane foam. It is not easy to deform in the production of foam plastics, and is an indispensable raw material for the manufacture of high-end mattresses, seat cushions and other products. The current development is also more optimistic. . Gaoqiao Petrochemical Company has successfully developed polymer polyol GPOP — H30 , which is a high-activity high-solid-content synthetic polyol with high activity polyether, styrene, acrylonitrile, macromonomer, polymerization control agent, initiator, etc. as the main raw materials. polymer polyol. The third chemical plant of the company built a 1_50,000 t / a polymer polyol plant, which is conducive to improving the quality of foam plastics in a large area in China.
In addition, the demand for high elastic polyether also has a certain room for growth.