Natural rubber thermoplastic vulcanizate

In this part, we will discuss AFM images and nanomechanical data obtained in smdies of natural and synthetic rubbers, thermoplastic elastomers (TPE), and their vulcanized counterparts— thermoplastic vulcanizates (TPV). 

Nakason, C., Tobprakhon, A., and Kaesaman, A. 2005. Thermoplastic vulcanizates based on poly(methyl methacrylate) /epoxidized natural rubber blends Mechanical, thermal, and morphological properties. Journal of Applied Polymer Science 98 3) 1251-1261. 

Thitithammawong, A., Nakason, C., Sahakaro, K., Noordermer., J. (2007). Effect of different type of peroxide on rheological, mechanical, and morphological properties of thermoplastic based vulcanizates based on natural rubber/ polypropylene blends. Polym, Test, 26, 537-546... 

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... 

Examples of vulcanizable elastomers include natural rubber (NR), styrene butadiene rubber (SBR), butadiene rubber (BR), ethylene-propylene-diene monomer-rubber (EPDM), butyl rubber (HR), polychloroprene or neoprene (CR), epichlorohydrin rubber (ECO), polyacrylate rubber (ACM), millable polyurethane rubber, silicone rubber, and flu-oroelastomers. Examples of thermoplastic elastomers include thermoplastic polyurethane elastomers, styrenic thermoplastic elastomers, polyolefin-based thermoplastic elastomers, thermoplastic polyether-ester (copolyester) elastomers, and thermoplastic elastomers based on polyamides. 

Thermoplastic Vulcanizate (TPV). TPVs are generally classified as f-TPV and p-TPV, wherein the prefixes indicate fully and partially vulcanized, respectively. Compounds of f-TPVs are typically made with EPDM and PP. In few special TPV compounds, EPDM is replaced by nitrile rubber, and natural rubber as well. The industry benchmark is TPV compounds, and they are sold under the trade name of Santoprene and marketed by Advanced Elastomer Systems (AES) Ltd. Mitsui is also dominant in the TPV based interior skins market in Europe. Seventy-five to 90 percent of TPV compounds are fully cross-linked with EPDM and are priced at approximately 1.80/lb. Two to 10 percent are par-... 

Natural rubber with over a century s use in many different products and markets will always be required to attain certain desired properties not equaled (to date) by synthetic elastomers. Examples include transportation tires, with their relative heat build-up resistance, and certain types vibrators. However, both synthetic TSE and TPE have made major inroads in product markets previously held only by natural rubber. Worldwide, more synthetic types are used than natural. The basic processing types are conventional, vulcanizable, elastomer, reactive type, and thermoplastic elastomer. 

Extensive reviews on short fibers-reinforced elastomers have been published by Goettler and Shen, ° and more recently by Rajeev. Table 7.11 is a list of selected published works on natural fiber-filled rubber composites, sorted by rubber type. Only vulcanizable rubbers were considered in preparing the table thermoplastic rubber and rubber-plastics blends were omitted. As can be seen most grades of conventional elastomers have been considered with quite a large variety of natural fibers. Natural Rubber, SBR, and EPDM compounds have received much attention, as expected with respect to their industrial importance. A bonding system is us in most cases, with resin types (i.e. resorcinol-formaldehyde, resorcinol-hexamethylenetetramine, sil-ica-resorcinol-hexamethylenetetramine) the most frequent ones. 

Used as a thermo/light-stabilizing phenolic antioxidant in the manufacture (compounding and end use) of white, light-colored, and transparent vulcanizates based on natural or synthetic rubber, PS, polyolefins, and pentaplast. Also used in POM and ABS thermoplastics because of its low volatility and migration properties. 

Until relatively recently, aU elastomers were vulcanized. However, thermoplastic elastomers were first introduced in 1954 with the introduction of urethane thermoplastic elastomers. Thus, the two major types of elastomers are vulcanizable (conventional) and thermoplastic elastomers. The conventional elastomers are frequently broadly classified as natural and synthetic rubbers. 

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