Analysis of the classification of thermoplastic elastomers

1. TPV-thermoplastic elastomer dynamic vulcanized rubber

Dynamic full vulcanization: refers to the chemical cross-linking of the rubber phase under the action of a crosslinking agent when the thermoplastic resin is melt blended with the rubber, and is sheared and broken into pieces by strong mechanical shearing action.

A process in which a large number of micron-sized crosslinked rubber particles are dispersed in a continuous phase of a thermoplastic resin.

When PP is a hard segment and EPDM is a soft segment for melt blending, a crosslinking agent which is vulcanized is added, and a mechanically highly sheared force such as an internal mixer or a screw machine is used to completely vulcanize.

The particles of the EPDM crosslinked rubber are sufficiently dispersed in the PP matrix in a micron size (less than 1 micron).

TPV has heat resistance and low compression deformation properties of vulcanized rubber;

Excellent processing performance: It can be processed by processing methods of thermoplastics such as injection and extrusion. It is efficient, simple and easy to operate, no need to add equipment, high fluidity and small shrinkage.

TPV does not require vulcanization for easy processing and common performance, which shortens the rubber industry production process by 1/4, saves energy by 25% to 40%, and improves efficiency by 10 to 20 times. It is another revolution in materials and process technology in the rubber industry.

The specific gravity is light (0.90-0.97), the appearance quality is uniform, the surface grade is high, and the hand feel is good. The performance characteristics of thermoplastic dynamic vulcanizate (TPV) include the following aspects (this data refers to the 11-64A “corresponding santoprene 101-64” quality checklist provided by the Daun Northernization TPV):

TPV can be used normally from -60 ° C to + 135 ° C; when it is not subjected to load, the high temperature resistance can reach +150 ° C.

Wide range of hardness and hardness, 25A-70D;

The advantages of easy dyeing greatly increase the freedom of product design.

Green, recyclable, and there is no significant decrease in performance after repeated use for six times;

TPV has excellent ozone and weather resistance;

TPV has dynamic fatigue resistance, excellent weather resistance and good wear resistance;

Good elasticity and compression set resistance, environmental resistance and aging resistance equivalent to EPDM rubber;

TPV has excellent corrosion resistance to water-based acid-base liquids and polar oils.

The oil and solvent resistance of TPV is comparable to that of general purpose neoprene.

TPV has excellent acid and alkali resistance and is highly resistant to acid-base detergents. It retains its original properties after long-term use in acid-base environments.

2, TPO-polyolefin thermoplastic elastomer

A simple physical blend of PP and EPDM (partially vulcanized), referred to as TPO.

In Japan, in addition to TPU, other thermoplastic elastomer materials are commonly referred to as TPO, that is, TPO=TPE=TPV=TPR, which is said by the Japanese; however, the current TPO is basically improved to highly vulcanized rubber (similar to TPV), but added Some SEBS are modified, so you need to ask more when you meet Japanese customers.

In 1984, Mitsubishi Chemical of Japan made a better performance mixture based on SEBS and SEPS, and named the saturated TPS as “Rubberron”. Therefore, SEBS and SEPS are not only general-purpose, but also melt-blended with PP plastic to form IPN-type TPS (so-called IPN, which is actually a polymer in which two networks are interpenetrated, so it is also called interpenetrating network compound; most of them It is a thermosetting resin, but there are also many thermoplastic elastomers such as TPE that are expressed in a cross-continuous phase. IPN-TPS formed by using SBS or SE8S as the substrate 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 modulus is not in the wide temperature range of low temperature. What changes have greatly improved the cold resistance and heat resistance of engineering plastics. The styrene compound and the rubber joint copolymer can also be made into thermoplastic TPE, and EPDM/styrene, BR/styrene, CI-IIR/styrene, NR/styrene and the like have been developed.

to sum up:

a, TPO and TPV are all polyolefin-based thermoplastic elastomers, in order to distinguish it from the TPV Forum, it is referred to as a polyolefin-based thermoplastic elastomer (also known as: thermoplastic elastomer partially vulcanized rubber);

b. TPO (TPO is basically a Japanese company, such as Riken TPO) is similar to the domestic TPV system, the price is around 45, and the production capacity is quite tight (the Japanese automotive industry consumes).

3. Thermoplastic elastomer TPE

Domestically known as "TPE" material, it is basically a styrenic thermoplastic elastomer.

Styrene-based TPE (known as TPS abroad) is a copolymer of butadiene or isoprene and styrene block type, and its performance is close to that of SBR rubber.

Advantages: high elasticity of rubber and injection molding processing characteristics; environmentally friendly, non-toxic, safe, excellent coloring, soft touch, weather resistance, fatigue resistance and temperature resistance, processing

Excellent performance, no need to vulcanize, can be recycled to reduce cost, can be double injection molding, coated with PP, PE, PC, PS, ABS and other base materials, or can be molded separately.

Disadvantages: The biggest problem with SBS and SIS is poor heat resistance, and the temperature should not exceed 80 °C. At the same time, its strength, weather resistance, oil resistance, wear resistance, etc. can not be compared with rubber.

In recent years, the United States and Europe have carried out a series of performance improvements, and SEBS and SEPS of saturated hydrogenation of SBS and SIS have appeared successively. SEBS (hydrogenation of BR as a soft segment) and SEPS (with IR hydrogenation as a soft segment) can greatly improve the impact strength, weather resistance and heat aging resistance.

Characteristics of modified TPE (SEBS/SEPS):

The modified TPE can withstand temperatures up to 110 ° C. The flame retardant, halogen-free flame retardant SEBS/SEPS modified TPE is more common in applications such as Apple earphone cords due to its good tensile strength and smooth surface. The manufacturer is from Taiwan, but it is expensive.

4. Styrene elastomer TPR: thermoplastic rubber

TPR was originally first introduced by Americans. At that time, there was no uniform naming of thermoplastic elastomers. It was customary to use the English acronym TPR for thermoplastic rubber and TPE for thermoplastic elastomers (both of which were used in related materials); Applied to a simple blend of PP and EPDM, then AES's PP/EPDM type TPV (originally called TPR later renamed TPV) also used this name, and later the name may be called by Taiwanese. And popular in the mainland.

No matter what foreign countries call it, China's domestic TPR and styrenic TPE belong to the same concept, which means thermoplastic styrene-butadiene-styrene block copolymer, which is called thermoplastic styrene-butadiene rubber, that is, domestic TPE=styrene. Class TPE.

However, due to historical and translation problems, the Chinese name for TPV (thermoplastic dynamic vulcanized rubber) is referred to as thermoplastic rubber (English Thermoplastic Rubber), which is TPR. This is why we don't tell our customers that our material PP/EPDM type TPV is called TPR, because some customers think it is a styrene elastomer, and if it is SBS base material, the price is much lower than the TPV.

5, polyurethane thermoplastic elastomer (referred to as TPU)

The polyurethane-based TPE is a thermoplastic polyurethane rubber which is block-bonded to each other by an isocyanate-reacted urethane hard segment and a polyester or polyether soft segment, abbreviated as TPU.

Advantages: TPU has excellent mechanical strength, wear resistance, oil resistance and flexural resistance, especially wear resistance is the most outstanding; temperature resistance: -30-120 ° C.

Disadvantages: heat resistance, hot water resistance, poor compression resistance, easy to yellow appearance, easy to stick mold, precise processing requirements, high processing costs.