Chain Multiplication of Fatty Acids to Precise Telechelic Polyethylene

Abstract

Starting from common monounsaturated fatty acids, a strategy is revealed that provides ultra long aliphatic a,w 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 a,w dicarboxylic fatty acid self metathesis products is shifted selectively to the statistically much disfavored a,b 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 a,w 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 8 8C) of aliphatic polyesters generated from these telechelic monomers, and by their self assembly to polyethylene like single crystals.

Periodic Polyethylene Sulfonates from Polyesterification: Bulk and Nanoparticle Morphologies and Ionic Conductivities

“…The crystallization of NBu 4 DSS was found to be slow, and, thus, no crystallization and no melting in the second heating cycle was observed in DSC (Figure S1). Polycondensation with octatetracontane-1,48-diol (generated from erucic acid 19 ) under classical melt conditions afforded PES48NBu 4 . In 1 H NMR spectra, signals were observed at 3.57, 3.58, and 3.41 ppm corresponding to the end groups of the polymer, that is the two methyl esters from the different incorporations of the ester monomer and the methylene group adjacent to the alcohol.…”

“…Octatetracontane-1,48-diol was synthesized according to the previously reported procedure. 19 Maleic acid was supplied by Acros Organics. Methanol (99.8%), sodium hydrogen carbonate, and sodium bisulfite were supplied by Merck.…”

Potentially Biodegradable “Short-Long” Type Diol-Diacid Polyesters with Superior Crystallizability, Tensile Modulus, and Water Vapor Barrier

“…For this reason, such PE-like aliphatic long-chain polyesters have attracted much attention from many researchers. Long-chain polyesters with various structures have been synthesized via a variety of polymerization methods, including not only traditional polycondensation of long-chain hydroxyl acids − or diol-diacid monomer pairs ,− and ring opening polymerization of macrocyclic lactones − but also (ring opening) metathesis (co)­polymerization of ester-containing noncyclic dienes or cyclenes followed by hydrogenation , and carbonylation polymerization . The combination of metathesis copolymerization and hydrogenation is very useful in synthesizing long-chain polyesters with very low ester bond fraction and therefore T m very close to high density polyethylene (HDPE). , Thermal, mechanical as well as biodegradability, ,− and gas barrier properties of some long-chain polyesters have also been reported.…”

Polyethylene-like materials from plant oils

“…[4,11] Even larger building blocks that exceed the length of a fatty acid chain (Figure 3, (d)) are accessible by 'chain multiplication' of common unsaturated fatty acids. [12] This fully catalytic, iterative scheme is based on a dynamic catalytic isomerizing crystallization in combination with an olefin metathesis step (Figure 4). With erucic acid as a substrate, the ultralong-chain linear C 48 diacid is generated in high purity and yield.…”

“…Notably, as these molecules themselves already crystallize like polyethylene, they can be considered as polyethylene telechelics. [12,13] The (ultra)long-chain ,-dicarboxylates can be reduced to the corresponding diols cleanly, most elegantly by catalytic reduction with dihydrogen. [8] These diols in turn can be converted to long-chain ,-diamines, by catalytic reaction with ammonia, [14,15] in a purity suited for polycondensation to long-chain polyamides.…”