Classification of thermoplastic elastomers:
1, TPV Thermoplastic Vulcanizate dynamic Vulcanizate rubber;
Dynamic full vulcanization: it refers to the process in which when thermoplastic resin and rubber are fused and blended, the rubber phase will generate biochemical crosslinking under the action of crosslinking agent, and with the help of strong mechanical shear action, it will be sheared and broken into a large number of micron crosslinked rubber particles, which will be dispersed in the continuous phase of thermoplastic resin.
When PP is taken as the hard chain segment and EPDM as the soft chain segment for melting blending, the crosslinker vulcanizing it is added, and the fully vulcanized particles of EPDM crosslinked rubber are fully dispersed in the PP matrix in micron size (less than 1 micron) by using the shear force of mechanical height such as internal mixer and screw machine.
Thermoplastic elastomer TPV characteristics
TPV with vulcanized rubber heat resistance and low compression deformation performance;
Excellent processing performance: injection, extrusion and other thermoplastic processing methods, efficient, simple and easy to operate, no need to add equipment, high mobility, small shrinkage.
TPV does not require vulcanization easy machining characteristics
Light specific gravity (0.90 -- 0.97), uniform appearance quality, high grade surface, feel good.
Taken the TPV at 60 ℃ ~ + 135 ℃ can be used normally;
Not under load, high temperature resistant to + 150 ℃.
A wide range of hardware and software applications, 25A -- 70D;
The advantages of easy dyeing greatly improve the freedom of product design.
Green environmental protection, recyclable, and repeated use of six times performance without obvious decline
TPV has excellent ozone and weather resistance;
TPV has dynamic fatigue resistance, excellent weather resistance, good wear resistance;
Good elasticity and compression deformation resistance, environmental resistance, aging resistance is equivalent to epdm;
Thermoplastic elastomer TPV < WBR >TPE < WBR >TPR < WBR >TPU
TPV has excellent corrosion resistance to water-base acid and alkali liquids and polar oils
TPV oil and solvent resistance is comparable to the general chloroprene rubber.
TPV has excellent acid and alkaline resistance, acid and alkali cleaners have a strong resistance, in the acid and alkali environment for a long time after the use can still maintain the original characteristics.
2. TPO - thermoplastic elastomer ThermoplasticPolyolefin;
A simple physical blend of PP and EPDM (partial vulcanization), or TPO for short.
In Japan, in addition to TPU, other thermoplastic elastomer materials are traditionally collectively referred to as TPO, that is, TPO=TPE=TPV=TPR;
However, the current TPO is basically improved into highly vulcanized rubber (similar to TPV), but some SEBS are added for modification, so we need to ask more questions when meeting Japanese customers.
In 1984, mitsubishi chemical made a mixture with better performance based on SEBS and SEPS, and named this saturated TPS "Rubberron" for market.
Therefore, SEBS and SEPS are not only general purpose, they are fused and blended with PP plastics to form ipn-type TPS (the so-called IPN is actually a polymer with two interpenetrating networks, so it is also called interpenetrating network compound;
Most of them belong to thermosetting resins, but there are also quite a few TPE like thermoplastic elastomers in the form of cross continuous phase).
IPN -- TPS formed with SBS or SE8S as the substrate and other engineering plastics can be directly coated without pretreatment;
Coating is not easy to scratch, and has a certain oil resistance, elastic coefficient in the low temperature wide temperature range without any change, greatly improve the cold and heat resistance of engineering plastics.
Styrene compounds and rubber grafting copolymerization can also become TPE with thermoplastic, has developed EPDM/styrene, BR/styrene, CI -- IIR/styrene, NR/styrene and so on.