While everyone is confident that China’s polyurethane industry is entering a rapid development phase, we should pay more attention to the future direction of polyurethane development, where technology is taking on difficult innovation challenges and where benefits are being raised by large amounts. Our perspective should be more in which areas to stay, I hope to read the following article, can be rewarded .
Polyurethane rigid foam and building energy efficiency Polyurethane rigid
Foam is a good thermal insulation product among all wall insulation materials at present, and it is also a forward-looking insulation material in the world. The Department of Science and Technology of the Ministry of Construction has set up a working group to promote the application of polyurethane building saving, and held an “International Conference on the Application of Polyurethane Wall Energy Saving Technology” in Beijing on October 10, 2006. The meeting agreed that polyurethane is a good performance insulation material in the world, with excellent performance of light quality, heat insulation, moisture-proof, sound insulation, heat resistance, shock resistance, corrosion resistance, easy bonding with other materials, and no molten droplets from burning. At present, polyurethane rigid foam in China is mainly used in heating, refrigeration, shipbuilding, petroleum, chemical, automotive, transportation and other industries, and the share used in building wall insulation is less than 10%, and about 49% of the building insulation materials in Europe and the United States and other developed countries are polyurethane materials. With the further improvement of domestic building energy-saving standards, a series of research institutions and enterprises around the field of insulation and energy saving are gradually increasing, and rigid polyurethane products will be “greatly developed” in the field of construction.
Polyurethane tires Polyurethane elastomer is a polymeric synthetic material with high hardness of plastic and high elasticity of rubber. Based on its excellent mechanical properties, research on the application of polyurethane elastomers in tires has been conducted since the 1960s. In particular, cast polyurethane elastomers are currently wear-resistant elastomers with the advantages of colorability, high cut resistance, vibration absorption, shock absorption, very high load capacity and excellent oil and chemical resistance, etc. They are also non-toxic to humans, fully biodegradable and do not require the addition of carbon black and aromatic oils, making them ideal materials for tire treads. Polyurethane tires are manufactured using a pouring process, and their structure is very different from that of currently produced tires. A fully polyurethane pneumatic tire is composed of three parts: the carcass, the belt ply and the tread. There are two forms of partial polyurethane pneumatic tires: one with a poured polyurethane carcass and a tread of rubber used in the manufacture of ordinary tires; the other with a radial carcass and a polyurethane tread. Polyurethane pneumatic tires have the following advantages over ordinary wire radial tires: (1) fuel consumption is 10% lower on average; (2) tread wear is 51% lower; (3) 30% lighter; (4) rolling resistance is more than 35% lower; (5) better uniformity and no tread peeling.
PU tires are available in all PU wheels (PP type) and PU inner tubes with rubber outer tires (RP type), which are suitable for various electric walkers, wheelchairs, children’s strollers, etc. Product advantages: good shock absorption, friction resistance, not afraid of nails, will not deflate, no patching safety, save money. However, there are still some problems to be solved in the research of polyurethane tires, namely, improving the traction and braking performance of polyurethane tires, improving the hydrolysis resistance, and the multiple injection molding process of heavy vehicle tires. In the process of developing polyurethane tires, the high temperature resistance is the main factor affecting the practicalization of polyurethane tires.
Environmental protection is another major issue facing the rising polyurethane industry. As polyurethane materials become more and more widely used in the national economy, the recycling of its waste is also gaining more and more attention. Waste polyurethane mainly includes edge waste and mold overflow from production plants, polyurethane foam and elastomer from end-of-life automobiles and refrigerators, used shoe soles and used PU leather and spandex old clothes. At present, there are three main methods for recycling polyurethane: physical method, chemical method and energy method.
For the recycling of waste polyurethane products, the European Union has taken the lead in introducing laws and regulations on the recycling of waste plastics of electrical products, and the principle is who produces who recycles; China should also speed up the recycling of polyurethane products, especially foam products. The recycling of polyurethane is undoubtedly beneficial to environmental protection and resource utilization, but the main problem also lies in whether recycling waste polyurethane has economic benefits. Due to the large amount of polyurethane, and the recent high price of raw materials, its waste recycling market has a good prospect, but the recycling methods used before are generally not economical and have not been widely promoted, therefore, the development of an economically feasible recycling method has become a hot spot for research in the industry.
Polyurethane wood imitation polyurethane material is injected into the mold by injection molding machine, and then taken out for post-painting process after solidification. Polyurethane products have the characteristics of low density, light weight, good dimensional stability, and not easy to deformation, etc. They can be used as structural support parts of furniture with embedded wooden rods and iron bars. Polyurethane wood material can be molded into various complex structures and carving patterns by modeling method, and can be planed, nailed and sawn, so it has the name of “synthetic wood”. Of course, in addition to the good molding performance, polyurethane wood-like furniture compared to traditional wood furniture, its price is more advantageous, and with the shortage of natural wood, environmental awareness, polyurethane wood-like furniture in Europe and the United States and other developed regions are increasingly popular. At present, there are relatively few enterprises producing PU imitation wood furniture in China, and even fewer of them are of a small scale, most of them are concentrated in the coastal areas of East China and South China, and all of their products are used for export, so there is great room for the development of polyurethane imitation wood furniture in the domestic market. In 2003-04, the domestic manufacturers engaged in the production of polyurethane imitation wood furniture, the export volume of their products is not much, but with 05 years later, the gradual decline in raw material prices, the overseas orders of these manufacturers are gradually increasing, each manufacturer is operating at full capacity, and some even began to expand production. According to rough calculations, the use of imitation wood hard foam reached 20,000 tons in 2005. According to the current international situation, the development of PU imitation wood furniture in the next few years in the country will gradually accelerate.
Spray Polyurea Elastomer Spray Polyurea Elastomer (Spray Polyurea Elastomer, referred to as SPUA) technology is a new type of solvent-free, pollution-free green construction technology developed to meet the needs of environmental protection after the low (no) pollution coating technology such as high solids coatings, water-based coatings, radiation-curing coatings, powder coatings, etc., which is based on the reaction injection molding (RIM) technology. It is developed on the basis of the reactive injection molding (RIM) technology, whose main raw material is end-amino polypropylene oxide ether (end-amino polyether). The end-amino polyether is combined with liquid amine chain extender, pigment, filler and auxiliaries to form a color paste (R component), while the other component is made by reacting isocyanate with oligomeric diol or triol (A component), and the A component and R component are sprayed by spraying equipment to produce polyurea elastomer. SPUA technology has broken through the limitations of traditional environmental protection coating technology and has better wear resistance, aging resistance, corrosion resistance and thermal stability. Therefore, this technology has been developed rapidly since its introduction.
The advantages of the non-phosgene method are: elimination of the use of dangerous phosgene, no corrosive hydrogen chloride, etc. At present, the non-mainstream isocyanate preparation methods with some practical value are carbon monoxide method (carbonylation method) and dimethyl carbonate method. Carbon monoxide method is the reaction of nitro compounds with carbon monoxide at high temperature and pressure to produce organic isocyanates. The process can be divided into two types of one-step and two-step method. The process is simpler, saving raw material consumption; disadvantage is the need for precious metal catalyst, yield is not high. However, in general, if the process is industrialized, the construction cost and production cost of the plant is much lower than that of photogasification. The method is simple and harmless, and solves many of the drawbacks of the photogas method. However, due to the high price of dimethyl carbonate, it is not as economical as the traditional method. With the continuous development of dimethyl carbonate and the expansion of production scale, its price will be gradually reduced. It is believed that this method will have more vitality nowadays when environmental problems are being paid more and more attention.
Compared with other conventional propylene oxide production processes, the advantage of the hydrogen peroxide production process (HPPO) is that only the end products of propylene oxide and water are produced during the production process, and no by-products are generated (the conventional ones are styrene or tert-butanol), and there is no problem of marketing other chemicals. Conventional production of propylene oxide by the chlorohydrin or styrene monomer process generates chlorine-containing waste or large amounts of styrene monomer, respectively. In the HPPO process, hydrogen peroxide is fully converted and propylene conversion is near quantitative values. A small amount of propylene exhaust stream enters the existing propylene network or is recycled to the reactor. The new plant footprint is very small and requires little supporting infrastructure, resulting in significant investment savings. The HPPO process for the production of propylene oxide has a hydrogen peroxide conversion of 99% and a propylene oxide selectivity of 95%. The HPPO process has been accelerated to industrialization by the construction of a HPPO plant in Antwerp, Belgium, in early 2006, with a new plant capacity of 300,000 tons/year of propylene oxide, which will be put into operation in 2008. In addition to Antwerp, an HPPO process for propylene oxide was built in 2009 in Gismar, USA. BASF and Dow Chemical are also considering building HPPO propylene oxide plants in Asia by 2010.
Water-based polyurethanes Water-based polyurethane dispersion resins (PUDs) have many advantages over other structural polymers and meet environmental requirements, mainly in the following ways:? Dispersed in water, no free isocyanate, no toxicity;? Good adhesion to substrates and good physical and mechanical properties, such as abrasion and impact resistance;? Good compatibility with other water-based polymers such as acrylics;? Low solvent content, in line with VOC emission requirements, even zero VOC. Water as the medium, non-toxic, non-flammable, non-polluting, non-hazardous, small odor, no pollution of the environment, energy saving, suitable for substrates susceptible to organic solvent erosion.
The disadvantages are: slow drying speed, low initial viscosity, and poor water resistance.
The development prospect of vegetable oil polyether polyol is promising At present, the existing production of polyether polyol mainly uses the downstream products of petroleum, such as propylene oxide and glycerol, which are resource-constrained and costly. In recent years, a few companies at home and abroad have made full use of some inexpensive vegetable oils such as soybean oil and palm oil as raw materials to develop a series of vegetable oil polyols to replace conventional polyether polyols. One of the U.S. companies that used vegetable oil to develop polyurethane polyols. These polyols can be produced in fewer steps, and the genetic modification of vegetable oils theoretically allows for industrial products to be derived directly from green plants. Dow is one of the companies testing elastomeric foaming polyols, and laboratory and pilot plant scale production has been successful. Current status of the polyether industry: Existing polyether polyols are produced mainly from propylene oxide and glycerol, which are downstream products of petroleum and are resource constrained and costly. Expected target: Different renewable natural oils, including linseed oil, rapeseed oil, soybean oil and castor oil, can be used to replace high-cost crude oil and natural gas raw materials to produce polyether polyols, which can be used to produce a variety of soft and rigid polyurethane products, mainly in the automotive, furniture, mattress and insulation materials.
In the next 10 to 15 years, vegetable oil-based polyols can replace petroleum-based component materials in the manufacture of polyurethane foams, elastomers, coatings, adhesives and sealants.
The United States is a leader in the production and development of non-isocyanate polyurethanes, and has successfully developed a non-isocyanate polyurethane alternative to conventional polyurethanes for coatings. Eurotech intends to commercialize these new polyurethanes for applications such as crack-resistant composites, chemical-resistant coatings, and sealants. A 500,000 ton per year plant was commissioned in Israel in 2001, and a “Cooperative Technology Development Agreement” was signed in 2001 for Eurotech’s hybrid non-isocyanate polyurethane (HNIPU). A-HNIPU is used in the manufacture of advanced functional coatings and adhesives with high gloss, excellent adhesion, good hardness and chemical resistance, and will be distributed in the U.S. and Europe as a new generation of polyurethane products. Non-isocyanate polyurethanes make up for the weak bond structure in conventional polyurethane molecules in terms of molecular structure, and have superior chemical resistance, hydrolysis resistance, and permeation resistance. In view of the above reasons, non-isocyanate polyurethanes have developed rapidly in recent years and are being industrialized in Western countries such as Europe and the United States, and are widely used in coatings, elastomers, adhesives and other industries, and have the potential to compete with conventional polyurethanes. Therefore, it is important to accelerate the research and development of non-isocyanate polyurethanes for the development of new polymeric materials in China. Non-isocyanate polyurethane has a very broad development prospect and is a new generation of polyurethane system.
Slow rebound foam for pressure reduction Nowadays, more and more urban white-collar workers begin to pay attention to sleep health issues. Mattress, no longer the traditional sense of sleeping furniture, but has been given more humane care and high-tech content.
Slow rebound early by the U.S. space agency NASA to develop a new material, as astronauts in space travel support and protection pad. This high-tech material can automatically adjust the shape of the suit according to the astronaut’s body shape and body temperature, so as to reduce pressure for the human body. With the development of technology, the high-tech material of yesteryear has found its new use in the civilian home industry. Compared with the ordinary sponge mattress, the slow rebound mattress taken from the astronautics materials, chemical and physical properties of stable, mite, anti-fungal, good breathability; professional ergonomic design, with adhesion, stretch and temperature sensitivity, can provide maximum comfort for the human body and when the pressure removed, the mattress can rebound to the original position without deformation. Because everyone’s height varies, some areas are not in contact at all. Slow rebound mattress has a unique buffer memory function, no matter how tall, short, fat or thin, lying in any position, the body can be in close contact with the mattress, when the body lying flat, the body is heavier, the back and hips naturally sink, the lighter waist is naturally held up, keeping the spine straight state, in line with ergonomic principles. No matter where you lie, you can adjust the shape of the mattress according to your body shape, and it is suitable for all people. PressureRelief, pressure and pain points to reduce to low, improve blood circulation, so that the body will not be sore and numb after a long time of operation.
PU pillow (Esl
