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Chain Multiplication of Fatty Acids to Precise Telechelic Polyethylene
Author(s) -
Witt Timo,
Häußler Manuel,
Kulpa Stefanie,
Mecking Stefan
Publication year - 2017
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201702796
Subject(s) - double bond , polyester , chemistry , reactivity (psychology) , catalysis , monomer , metathesis , polymerization , polymer chemistry , organic chemistry , olefin fiber , acyclic diene metathesis , chain (unit) , polyethylene , crystallization , polymer , medicine , alternative medicine , pathology , physics , astronomy
Starting from common monounsaturated fatty acids, a strategy is revealed that provides ultra‐long aliphatic α,ω‐difunctional building blocks by a sequence of two scalable catalytic steps that virtually double the chain length of the starting materials. The central double bond of the α,ω‐dicarboxylic fatty acid self‐metathesis products is shifted selectively to the statistically much‐disfavored α,β‐position in a catalytic dynamic isomerizing crystallization approach. “Chain doubling” by a subsequent catalytic olefin metathesis step, which overcomes the low reactivity of this substrates by using waste internal olefins as recyclable co‐reagents, yields ultra‐long‐chain α,ω‐difunctional building blocks of a precise chain length, as demonstrated up to a C 48 chain. The unique nature of these structures is reflected by unrivaled melting points ( T m =120 °C) of aliphatic polyesters generated from these telechelic monomers, and by their self‐assembly to polyethylene‐like single crystals.