Polyolefin thermoplastic elastomers TPEs

Cross-Linking of Polyolefin/Elastomer or Polyolefin/Thermoplastic Elastomer (TPE)... 

Thermoplastic elastomers (TPE s) are characterized by the exceptional property that, without vulcanization, they behave as cross-linked rubbers. They are block-copolymers, in which blocks of the same nature assemble in hard domains, acting as cross-links between the rubbery parts of the chain. These hard domains lose their function when they reach their softening temperature, so that the material can then be processed as a thermoplast. One of the oldest member of the family of TPE s is SBS (styrene-butadiene-styrene block copolymer), but several other TPE s have been developed, i.a. on the basis of polyesters, polyurethanes and polyolefins. In their properties these polymers cover a broad range between conventional rubbers and soft thermoplastics. 

TPOs are basically two-component elastomer systems consisting of an elastomer finely dispersed in a thermoplastic polyolefin (such as polypropylene). The thermoplastic polyolefin is the major component. Thermoplastic elastomers (TPEs) include TPOs, TPVs (thermoplastic vulcanizates), etc. Properties of TPOs depend upon the types and amounts of polymers used, the method by which they are combined, and the use of additives such as oils, fillers, antioxidants, and colors. Blends and reactor-made products compete primarily with other TPEs and metals. There are vulcanizates (TPVs) that have higher elastomeric properties. They compete primarily with TS elastomers. 

The following TPs are the main thermoforming materials processed high-impact and high-heat PS, HDPE, PP, PVC, ABS, CPET, PET, and PMMA. Other plastics of lesser usage are transparent styrene-butadiene block copolymers, acrylics, polycarbonates, cellulosics, thermoplastic elastomers (TPE), and ethylene-propylene thermoplastic vulcanizates. Coextruded structures of up to seven layers include barriers of EVAL, Saran, or nylon, with polyolefins, and/or styreneics for functional properties and decorative aesthetics at reasonable costs.239-241... 

There are two classes of polyolefin blends elastomeric polyolefin blends also called polyolefin elastomers (POE) and nonelastomeric polyolefin blends. Elastomeric polyolefin blends are a subclass of thermoplastic elastomers (TPEs). In general, TPEs are rubbery materials that are processable as thermoplastics but exhibit properties similar to those of vulcanized rubbers at usage temperatures (19). In TPEs, the rubbery components may constitute the major phase. However, TPEs include many other base resins, which are not polyolefins, such as polyurethanes, copolyamides, copolyesters, styrenics, and so on. TPEs are now the third largest synthetic elastomer in total volume produced worldwide after styrene-butadiene rubber (SBR) and butadiene mbber (BR). 

Blends of EPDM rubbers with polypropylene in suitable ratios have been marketed as thermoplastic elastomers (TPE), also commercially known as thermoplastic polyolefin elastomers (TPO). These heterophasic polymers, characterized by thermoreversible interaction among the polymeric chains, belong to a broad family of olefinic alloys that can now be produced directly during the polymerization phase, unlike blended TPE and TPO, and various compositions (with various compounding additives) can be formulated which are primarily tailored to meet different requirements of most of car applications. The TPE-based synthetic leather and foam sheets are typical examples. 

Chem. Descrip. Highly refined wh. mineral oil USP CAS 8020-83-5 EINECS/ELINCS 232-455-8 Uses Melt flow control agent tor crystal PS, HIPS, polyolefins, thermoplastic elastomers, other polymers internal and external lubricant in PS, PVC, PP, PE, TPE, other polymers carrier in pharmaceuticals protective coating on foods... 

Thermoplastic elastomers (TPEs) are an extremely fast growing segment of polymer manufacturing. A rate of 5% growth per year is expected until 2007, at which time the total U.S. demand for these materials will reach 1.5 billion lb at a total annual sales of approximately 3 billion dollars per year [1]. The majority of this growth comes in the form of replacements for other types of materials, and the growth of so-called soft-touch surfaces. In the approximately 10 years since the second edition of this book appeared, there has been an important technological advancement in this area the vastly increased production of thermoplastic polyolefin elastomers as a result of the worldwide adoption of metallocene catalysts. 

Thermoplastic elastomer (TPE) blends have been broadly studied as a new class of materials. TPEs offer various advantages and require no state-of-the-art processing machinery, while scrap and rejects are recyclable. Blends can be homogeneous, phase separated or both. TPEs are multi-phase polymer systems consisting of hard and soft domains that can be copolymers or mechanical blends. This phase separation leads to materials having unique and viable commercial physical properties. TPEs exhibit the thermoplastic characteristics of the hard thermoplastic phase, and resilience as a result of the rubbery domains. TPEs based on natural rubber (NR) and thermoplastic blends are known as thermoplastic natural rubber (TPNR) blends. There are two types of TPNR, namely thermoplastic polyolefin (TPO) and thermoplastic vulcanizate (TPV).3... 

Thermoplastic elastomers (TPEs), which combine the characteristics of both thermoplastics and elastomers, can be classified into two major groups. The first is made up of block copolymers formed by polymerizing a thermoplastic monomer with an elastomer comonomer, as in the case of styrene block copolymers such as styrene-ethylene-butadiene-styrene (SEBS). Engineering TPEs such as thermoplastic urethanes (TPUs), copolyesters (COPEs) and polyether block amides (PEBAs) can be included in this first group. Other types of copolymer are from the polyolefin family, consisting of the polyolefin... 

The family of elastomers known as thermoplastic elastomers (TPEs) are based on crosslinked polyolefin alloys and are compounded with common... 

Thermoplastic Elastomers (TPE) are classes of heterophasic polymers, characterized by thermo-reversible interaction among the polymeric chains. The new polymeric materials that are considered to produce easy recyclable automotive systems, can be defined as a sort of a new generation of Olefinic Thermoplastic Elastomers (TPO), belonging to a broad family of polyolefinic alloys that can now be produced directly dining the polymerization phase. These completely new materials, resulting from advanced research and development carried out by HIMONT, can be tailored in order to meet different requirements of most of car apphcations. The basic partly finished components suitable for the constructions of the main automotive composite structru-es will be described. 

Polyolefin-based thermoplastic elastomers (TPEs) have received considerable attention due to their chemical inertness, low density, and low cost compared with other TPEs. Homogeneous ethylene-octene (EO) copolymers, synthesized via contemporary catalyst technology, with low crystallinity and low density (0.86-0.88g/cm ) exhibit the characteristics of thermoplastic elastomers. The elastomeric properties depend on the fringed micellar crystals which serve as network junctions. However, the low melting point of fringed micellar crystals have limited the application of elastic EO copolymers at higher temperatures. 

Currently, important TPE s include blends of semicrystalline thermoplastic polyolefins such as propylene copolymers, with ethylene-propylene terepolymer elastomer. Block copolymers of styrene with other monomers such as butadiene, isoprene, and ethylene or ethylene/propy-lene are the most widely used TPE s. Styrene-butadiene-styrene (SBS) accounted for 70% of global styrene block copolymers (SBC). Currently, global capacity of SBC is approximately 1.1 million tons. Polyurethane thermoplastic elastomers are relatively more expensive then other TPE s. However, they are noted for their flexibility, strength, toughness, and abrasion and chemical resistance. Blends of polyvinyl chloride with elastomers such as butyl are widely used in Japan. ... 

In addition to the two-phase TPEs, two new technologies have emerged. They are the metallocene-catalyzed polyolefin plastomers (POPs, the name given to Exxon s EXACT product line) and polyolefin elastomers (POEs, DuPont Dow Elastomer s ENGAGE), and reactor-made thermoplastic polyolefin elastomers (R-TPOs). These new types of TPEs are often called metallocene elastomers-TPEs (MEs-TPEs) [87]. The new POPs and POEs are essentially very low-molecular-weight-Unear low-density PEs (VLMW-LLDPE). These new-generation TPEs exhibit mbber-like properties and can be processed on... 

Thermoplastic elastomers contain sequences of hard and soft repeating units in the polymer chain. Elastic recovery occurs when the hard segments act to pull back the more soft and rubbery segments. Cross-linking is not required. The six generic classes of TPEs are, in order of increasing cost and performance, styrene block copolymers, polyolefin blends, elastomeric alloys, thermoplastic urethanes, thermoplastic copolyesters, and thermoplastic polyamides. 

TPE grades are often characterized by their hardness, resistance to abrasion, cutting, scratching, local strain (deformation), and wear. The generic types of TPE are styrenics, thermoplastic polyolefins (TPO), polyurethane thermoplastic elastomers... 

TPEs which are prepared by physical blending of an elastomer with a thermoplastic. Such TPEs are categorized into two types depending on rubber vulcanization (i) thermoplastic olefins (TPOs) or thermoplastic elastomer polyolefins (TEOs) (ii) thermoplastic vulcanizates (TPVs). 

TPE n Abbreviation for Thermoplastic Elastomer. TPO n Abbreviation for Thermoplastic Polyolefin. TPP n Abbreviation for Triphenyl phosphate. 

The most important examples of thermoplastic elastomers include TPE-0 (polyolefin-based TPE), TPE-A (polyether(ester)-block-amide), TPE-E (copolyester-based TPE), TPE-S (styrene copolymer-based TPE), and TPU (polyurethane-based TPE). 

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