Synthesis and characterization of poly‐n‐alkylmalonamides: Formation of a partially disordered layer structure

Abstract

synopsisPolyamides from n-alkylmalonic acids and linear aliphatic diamines, with paraffinic side chains of 3-18 carbon atoms, were prepared by melt polycondensation or by lowtemperature interfacial polycondensation and were characterized by infrared, differential scanning calorimetry (DSC), and x-ray diffraction techniques. Firsborder transitions were found in the range of 130-21OoC, depending on the number of carbon atoms in the side chain. The x-ray diffraction indicated substantially amorphous systems for polyamides with 8-18 carbon atoms in the side chain. However, longrange order arises in these polymers from a solid-state structure in which polyamide and hydrocarbon layers having partially disordered chain conformations alternate.

Phase Transition and Conformational Variation of N-Alkylated Branched Poly(ethyleneimine) Comblike Polymer

“…25 More specifically, the alkyl side chains, which have a profound influence on the microstructure of the comblike polymer, introduce some unique properties such as solvatochromic behavior and reversible thermochromic transition between low and high-temperature solid-state phases. 37 Jordan studied the thermal behavior of a series of comblike polymers, such as poly(n-alkyl acrylates), 3,4 poly(N-n-alkylacrylamide), 5,6 poly(N-n-alkylmaleimide), [7][8][9] and poly(vinyl ester) 10,11 with unbranched alkyl side chains containing 12-22 carbon atoms by using DSC method. The authors thought that only the outer alkyl side chains, exceeding 8-10 methylene groups, are able to crystallize.…”

“…They differ from the ordinary branched polymers by number and density of the side chain, which results in the appearance of some new properties. Synthesis, structure, and properties of comblike polymers have been extensively researched in the passed several decades, and many original investigations and reviews have been published. − The first comblike polymer was synthesized by Rehberg and Fisher through polymerizing n -alkyl acrylates, and since then this type of polymer has been a permanent subject for synthesis chemistry and physical characterization as well as materials modification and processing. Comblike polymers are generally divided into two sorts, considering the rigidity of the backbones: rigid-rod main-chain polymers and flexible main-chain polymers, both of which are grafted with long flexible side chains.…”