Styrene TPE, also known as TPS, is a block polymer of butadiene or isoprene and styrene, and its performance is closest to SBR rubber. It is one of the earliest varieties of chemically synthesized thermoplastic elastomer and the largest TPE in the world at present. The representative variety is styrene-butadiene-styrene block copolymer (SBS), which is widely used in footwear industry and has largely replaced rubber. At the same time, its application in industrial rubber products such as adhesive tape and rubber sheet is also expanding. SBS is also widely used as an impact modifier for PS plastics, and it is also an excellent modifier for wear resistance, crack resistance, softness resistance and skid resistance of asphalt pavement. PS plastics modified by SBS can not only greatly improve the impact resistance like rubber, but also have very good transparency. Compared with SBR and WRP rubber powder, SBS modified asphalt pavement is easier to dissolve in asphalt. So although the price is more expensive, it is still widely used. Now the waterproofing membrane is further extended to the waterproofing and moistureproof of building roofs, subways, tunnels and ditches. Sponges made of SBS, S-SBR and NP rubber are richer in rubber touch than the original PVC and EVA plastic sponges, lighter than vulcanized rubber, with bright colors and clear patterns. Therefore, it is not only suitable for making sponges in rubber overshoes, but also an ideal material for disposable soles such as travel shoes, sports shoes and fashion shoes. In recent years, block styrene polymers (S-work S) with isoprene replacing butadiene have developed rapidly, and about 90% of them are used as adhesives. The biggest problem of SBS and SIS is that they are not heat-resistant, and the service temperature generally cannot exceed 80℃. At the same time, its tensile strength, weather resistance, oil resistance and wear resistance are incomparable to rubber. Therefore, in recent years, the United States and Europe and other countries have made a series of performance improvements, and SEBS and SEPS with saturated hydrogenation of SBS and SIS have appeared successively. SEBS (with BR hydrogenation as soft segment) and SEPS (with IR hydrogenation as soft segment) can greatly improve impact strength, weather resistance and thermal aging resistance. 1984 Mitsubishi chemical of Japan made a mixture with better performance on the basis of SEBS and SEPS, and named this saturated TPS "Rubberron" for listing. Therefore, SEBS and SEPS are not only universal, but also mixed materials of engineering plastics to improve weather resistance, wear resistance and thermal aging resistance, so they have rapidly developed into compatibilizers for engineering plastics such as nylon (PA) and polycarbonate (PC). In addition, many new varieties have been developed, such as highly transparent thermoplastics for epoxy resin and bio-nontoxic thermoplastics for medical care. IPN TPS can also be formed when SBS or SEBS is melted and mixed with PP plastic. The so-called IPN is actually a polymer with two interpenetrating networks, so it is also called interpenetrating network compound. Although most of them belong to thermosetting resins, there are also many thermoplastic elastomers like TPE in the form of cross continuous phases. TPS formed by IPN——SBS or SES and other engineering plastics can be directly coated without pretreatment. The coating is not easy to scratch and has certain oil resistance, and the elastic coefficient does not change in a wide temperature range at low temperature; The cold resistance and heat resistance of engineering plastics are greatly improved. Styrene compound grafted rubber can also become thermoplastic TPE, and EPDM/ styrene, BR/ styrene, CI-IIR/ styrene, NP/ styrene and so on have been developed.

2. olefin TPE

Olefin TPE is a mixture of PP as hard segment and EPDM as soft segment, which is called TPO for short. Because its specific gravity is lighter than other TPEs (only O.88), its heat resistance is as high as 100℃, and its weather resistance and ozone resistance are good, it has become another fast-growing variety of TPE. Dynamic partial vulcanization TPO appeared in 1973, and full dynamic vulcanization TPO appeared in 198 1 year, which greatly improved the performance and the highest temperature reached 120℃. This dynamic vulcanization TPO is called TPV for short. When the mixture of PP and EPDM is melted and mixed by TPO, the crosslinking agent which can vulcanize it is added, and the fully vulcanized fine EPDM crosslinked rubber particles are fully dispersed in the PP matrix by using the high shear force of internal mixer, screw machine and other machinery. Through the "particle effect" of this cross-linked rubber, the compression deformation resistance, thermal aging resistance and oil resistance of TPO are obviously improved, even reaching the level of CR rubber, so people call it thermoplastic vulcanizate. Using the oil resistance of TPV instead of NBR and CR to manufacture various rubber products. TPV can also be mixed with PE*** and used with other TPEs such as SBS to improve performance. Now it has been widely used as gears, racks, ignition wire sheaths, oil-resistant hoses, air ducts, anti-crack gloss sealing strips, wires and cables, food, medical care, etc. in high-rise buildings, and its growth rate greatly exceeds TPS. In recent years, polymer TPO was introduced on the basis of TPV, which made a new breakthrough in the toughness and low temperature resistance of TPV. The United States has also developed IPN TPO with better comprehensive performance. A completely dynamically vulcanized PP/NBR-TPV appeared in 1985. Part of PP was grafted with maleic anhydride, and part of NBR was treated with amine to form amine-terminated NBR. This * * * polymer can form a small amount of graft and block during dynamic vulcanization, and can replace nitrile rubber for seals and hoses in airplanes, automobiles and machinery. This * * * mixture is incompatible with each other because of the different polarities of the two materials, so MAC compatilizer must be added when mixing. This kind of compatibilizer mainly includes: ethylene polyamine compounds, such as diethylenetriamine or triethylenetetramine, and liquid nitrile rubber and polypropylene maleic anhydride compounds. In Malaysia, PP/NR TPV was successfully developed in 1988. Its tensile and tear strength is very high, and its compression deformation is greatly improved. Its heat resistance can reach 100- 125℃. At the same time, PP/ENR-TPV was also developed, which was obtained by reacting NR with peracetic acid to prepare epoxidized NR, and then melt blending with PP. Its performance was better than PP/NR-TPV and PP/NBR-TPV, and it was used in automobile parts, wires and cables. During this period, PP/IIR-TPV, PP/CI-IIR-TPV appeared in Britain, a series of melt * * * blends such as PP/SBR, PP/BR, PP/CSM, PP/ACM and PP/ECO were developed in the United States, and PP/EVA was made in Germany to mix PP * * * with various rubbers. In addition, there are EPDM/PVC, IIR/PE and so on. At present, TPE in the form of * * * compound prepared by dynamic full vulcanization technology has covered 1 1 kinds of rubber and 9 kinds of resins, and 99 kinds of rubber-plastic compound can be prepared. The crosslinking density of vulcanized rubber reached 7× 10-5mol/ml (measured by swelling method), that is, 97% of rubber was crosslinked, the tensile elongation was greater than 100%, and the tensile permanent set was less than 50%. TPV can produce various parts through blow molding, injection molding and extrusion molding commonly used in plastic processing. Blow molding products include automobile air purifier duct, gear cover protective sleeve, coupling protective sleeve, etc. Injection molding products include spark plug gasket, reflector gasket, pedal brake gasket, brake booster guide tube sheath, crankshaft cover sheath and so on. , you can also make synchronous belts. Extruded products include wire and cable sheaths, outer rubber of fuel pipes and various sealing strips. Especially for automobile sealing strips, the use of TPV has become fashionable, including solid and foam products, static sealing and quasi-dynamic/dynamic sealing products. , has basically replaced rubber. At present, in olefin-based TPE, TPO accounts for about 80%-85%, and TPV accounts for about 15%-20%. In order to adapt to different processing methods and uses, it is generally 10-20. Although most of them have not announced the specific production methods and output, they are nothing more than various molten olefin mixtures. Melt * * * mixed TPV is becoming a new rubber and plastic material, and it is also the hottest research and development topic for rubber and plastic manufacturers. There are various TPO-TPV blends, such as EPDM/PP TPV and NBR/PP TPV, ACM/PP TPV and EPDM/PA-TPV, which are also becoming new modified * * * blends.

3. diene TPE

Diene TPE is mainly an isomer of natural rubber, so it is also called thermoplastic trans natural rubber (1-NR). As early as 400 years ago, people discovered that this material is natural rubber, but it is called Gupta rubber and balata rubber because it is produced in wild trees such as Gupta and balata, which is different from the three-leaf rubber tree. Although this T-NR has been used as the skin of submarine cables and golf balls for more than 65,438+000 years, its use has not been expanded for a long time due to its thermoplastic state, strong crystallinity and limited supply. After 1963, the United States, Canada, Japan and other countries successively used organometallic catalysts to manufacture and synthesize T-NR- trans polyisoprene rubber, which was called TPI. Its microstructure is just opposite to that of isoprene rubber (IR), with 99% trans-bonding, 40% crystallinity and melting point of 67℃, which is very similar to natural Gutap and balata rubber. Therefore, natural products are gradually replaced and further developed into plastic surgery instruments, gypsum substitutes and sports protective equipment. In recent years, TPI has been successfully developed as a shape memory rubber material because of its excellent crystallinity and temperature sensitivity, which is favored by people. Structurally, TPI is a thermoplastic rubber with high crystallinity, which is composed of trans structure as hard segment and then combined with other arbitrary soft segments in elastic phase. Compared with other TPE, it has the advantages of good mechanical strength, damage resistance and vulcanization, but the disadvantage is that the softening temperature is very low, generally only 40-70℃, and its use is limited. China is also developing a large number of Eucommia rubber from Eucommia ulmoides trees in Hunan, Hubei, Sichuan and Guizhou. It is also a kind of trans-1 4- polyisoprene natural rubber with rich resources and great development potential. 1974, Japanese companies successfully developed the isomer of BR rubber (cis-1, 4 polybutadiene)-syndiotactic 1, 2 polybutadiene, abbreviated as TPB. It is syndiotactic polybutadiene rubber with 1, 2- position combination exceeding 90%. The microstructure is a block polymer composed of crystalline parts with the same structure between any soft segment and hard segment. Although its heat resistance and mechanical strength are not as good as rubber, it is widely used in industrial rubber products such as shoes, sponges and optical films because of its good transparency, weather resistance, electrical insulation and photodegradation. The biggest difference between TPB and TPI is that it can be vulcanized. It solves the problem that general TPE cannot be vulcanized by sulfur and peroxide, but must be vulcanized by special devices such as electric wave and radiation. It can improve the quality and modification, thus improving the shortcomings of TPE such as poor heat resistance, oil resistance and durability. TPB can be processed at will in the melting point range of 75- 1 10℃, and can be used to produce unvulcanized injection-molded slippers and casual shoes, as well as to vulcanize and foam the midsole of sports shoes and travel shoes. Compared with EVA sponge midsole, it is not easy to collapse and deform, and it is comfortable to wear, which is beneficial to improve the effect of sports competition. The film made of TPB has good air permeability, water resistance and transparency, is easily decomposed by light, is very safe, and is especially suitable for fresh-keeping packaging of families, vegetables and fruits.

4. Vinyl chloride thermoplastic elastomer

Vinyl chloride thermoplastic elastomers can be divided into two categories: thermoplastic polyvinyl chloride and thermoplastic chlorinated polyethylene. The former is called TPVC and the latter is called TCPE. TPVC is mainly the elastic modification of PVC, which is divided into two forms: chemical polymerization and mechanical blending. Mechanical blending is mainly a mixture (PVC/NBR) formed by mixing partially crosslinked NBR into PVC. In fact, TPVC is just an extension of soft PVC resin, only because the compression deformation is greatly improved, thus forming a rubber-like PVC. This TPVC can be regarded as a modified product of PVC and a substitute of rubber, which is mainly used to manufacture rubber hoses, rubber sheets, adhesive tapes and some rubber parts. At present, more than 70% are consumed in the automotive field, such as steering wheel, wiper blade and so on. For other purposes, wires account for about 75%, and building waterproof membrane accounts for about 10%. In recent years, it has been extended to household appliances, gardening, industry and daily raincoats. At present, a large number of blends of PVC and NBR, modified PVC and crosslinked NBR are sold in the international market, which has become the most successful example of rubber and plastics. NBR manufacturers in the United States, Japan, Canada, Germany and other countries have produced a large number of NBR products, and independently formed PVC/ NBR materials in industry, and used them to manufacture a large number of rubber products such as rubber hoses, rubber sheets and tapes. * * * The mixture of PVC and other polymer materials, such as PVC/EPDM, PVC/PU, PVC/EVA, and the graft products of PVC with ethylene and acrylate have also come out and been put into production. With the increasingly strict requirements of environmental protection, it is always difficult to completely solve the problem of TPVC acid gas escaping and polluting the environment. Recently, the growth rate in the world has declined, and the application scope has been greatly affected. The main TPVC used in China is HPVC, which has been studied since 1990s, and only a small amount of TPVC is produced and supplied. At present, PVC/NBR and PVC/EVA*** are mostly mixed. Except for a few commodities, most of them are mixed by rubber processing plants and are widely used to manufacture oil tanks, rubber hoses and rubber shoes. , and has partially replaced CR and NBR, NR and SBR. The effect is very good, and the consumption is expanding year by year. TCPE with TPE function mixed with CPE rubber and CPE resin also has applications. In the future, TPVC and TCPE may become new rubber and plastic materials to replace some NR, BR, CR, SBR, NBR rubber and PVC plastics in China.

5. Polyurethane TPE

Polyurethane TPE is a kind of thermoplastic polyurethane rubber, which consists of polyurethane hard segment and polyester or polyether soft segment that react with isocyanate. TPU has excellent mechanical strength, wear resistance, oil resistance and flexibility, especially wear resistance. Disadvantages are poor heat resistance, hot water resistance and pressure resistance, easy yellowing of appearance and easy mold sticking during processing. At present, it is mainly used to manufacture sports goods such as ski boots and hiking shoes in Europe and America, and a large number of sports shoes and travel shoes are produced, which consumes a lot. TPU can also be used to produce automobile, machinery, clocks and other parts by injection molding and extrusion, and is widely used in high-pressure hoses (outer rubber), pure hoses, sheets, transmission belts, conveyor belts, wires and cables, adhesive tapes and other products. Injection molding accounts for more than 40%, and extrusion molding accounts for about 35%. In recent years, in order to improve the processability of TPU, many new easy-to-process varieties have appeared. If it is suitable for two-color molding, it can increase transparency, high fluidity and high recovery, and improve processing and production efficiency. TPU with no plastic, low hardness and easy processing is used to manufacture transparent rubber hose. It can be used as a special TPU for large parts such as automobile bumper, reinforced with glass fiber, which can improve rigidity and impact resistance. Especially when reactive components are added to TPU, after thermoplastic molding, incomplete IPN (IPN formed by crosslinked polymer and non-crosslinked polymer) develops rapidly. This IPN TPU further improves the physical and mechanical properties of TPU. In addition, TPU/PC*** mixed alloy TPU further improves the safety performance of automobile bumper. In addition, there are high moisture permeability TPU, conductive TPU, TPU and so on, which are specially used for living bodies, tapes, safety glasses and so on.