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Ultra-high-molecular-weight polyethylene (UHMWPE, UHMW) is a subset of the thermoplastic polyethylene. Also known as high-modulus polyethylene, (HMPE), or high-performance polyethylene (HPPE), it has extremely long chains, with a molecular mass usually between 2 and 6 million u. The longer chain serves to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions. This results in a very tough material, with the highest impact strength of any thermoplastic presently made.〔Stein, H. L. (1998). Ultrahigh molecular weight polyethylenes (uhmwpe). Engineered Materials Handbook, 2, 167–171.〕 UHMWPE is odorless, tasteless, and nontoxic.〔Wong, D.W.S.; Camirand, W.M.; Pavlath, A.E.; Krochta, J.M.; Baldwin, E.A. and Nisperos-Carriedo, M.O. (eds.) (1994) "Development of edible coatings for minimally processed fruits and vegetables" pp. 65–88 in ''Edible coatings and films to improve food quality'', Technomic Publishing Company, Lancaster, PA. ISBN 1566761131〕 It is highly resistant to corrosive chemicals except oxidizing acids; has extremely low moisture absorption and a very low coefficient of friction; is self-lubricating; and is highly resistant to abrasion, in some forms being 15 times more resistant to abrasion than carbon steel. Its coefficient of friction is significantly lower than that of nylon and acetal, and is comparable to that of polytetrafluoroethylene (PTFE, Teflon), but UHMWPE has better abrasion resistance than PTFE. ==Development== Polymerisation of UHMWPE was commercialised in the 1950s by Ruhrchemie AG, which changed names over the years. Today UHMWPE powder materials, which may be directly molded into a product's final shape, are produced by Ticona, Braskem, and Mitsui. Processed UHMWPE is available commercially either as fibers or in consolidated form, such as sheets or rods. Because of its resistance to wear and impact, UHMWPE continues to find increasing industrial applications, including the automotive and bottling sectors. Since the 1960s, UHMWPE has also been the material of choice for total joint arthroplasty in orthopedic and spine implants. UHMWPE fibers, commercialized in the late 1970s by the Dutch chemical company DSM, are widely used in ballistic protection, defense applications, and increasingly in medical devices. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Ultra-high-molecular-weight polyethylene」の詳細全文を読む スポンサード リンク
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