Cocrystallization Behavior of Poly(3-alkylthiophenes):  Influence of Alkyl Chain Length and Head to Tail Regioregularity

Abstract

The cocrystallization behavior of poly(3-alkylthiophene)s (P3ATs) of varying regioregularity and alkyl chain length was explored via differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS) studies. For the regioregular samples both DSC and WAXS studies revealed that cocrystallization was limited to the difference of the alkyl chain length by two carbon atoms. On the other hand, P3AT samples with the same alkyl chain length but different regioregularities cocrystallized with a difference of 17 mol % head to tail (H-T) regularity studied here. P3AT samples with varying regioregularity and alkyl chain length by two carbon atoms showed cocrystallization for a regioregularity difference of 7 mol %. The WAXS study indicated that cocrystals had crystallized within the same interchain lamella and noncocrystals had crystallized within the independent interchain lamella of the components. It also indicated the formation of type 1 P3AT crystals with a noninterdigited side chain during the cocrystallization by melt-quenched conditions for all the samples. The phase diagrams clearly revealed that in some systems at the lower melting component rich region there exist two phase regions. The conductivity of the cocrystals, in both the doped and undoped states, is either intermediate or lower than the line joining their component conductivity values.

Physical properties of poly(n-alkyl acrylate) copolymers. Part 1. Crystalline/crystalline combinations

“…Typically when both units are capable of crystallizing, the melting point shows depressions on both sides of the T m composition diagram resembling a eutectic while crystallinity may go to zero, or reach a minimum, in the midcomposition range. The other is where the two units cocrystallize with the typical signature of a steady, monotonic progression of the melting point and heat of fusion from that of the one homopolymer to that of the other as composition changes [27][28][29][30][31][32][33][34]. As will be shown in the following, this is the more common situation in the copolymers described here.…”

Spectroelectrochemistry of poly(3-hexylthiophenes) in solution

“…These properties are shaped by the chemical structure of the repeat unit (Pal and Nandi 2003), the length of the polymer chain (Kline et al 2005) and by its topology (Willot et al 2013). Control over the structure of the repeat unit and the length of the polymer chain has been long exercised; achieving a desired topology of the polymer chain, however, requires the use of advanced polymerisation procedures (Dou et al 2014; McCullough and Lowe 1992; Loewe et al 1999; Osaka and McCullough 2008; Seung-Hoi and Rieke 2009) or the polymerisation of a regio-locked monomer (Jarosz et al 2014; Zagorska and Krische 1990; Souto Maior et al 1990).…”

Regulation of crystalline morphologies and mechanical properties of olefin multiblock copolymers by blending polymer with similar architecture of constituent blocks

“…[41][42][43][44][45] In general, there are three requirements for this process: structural similarity, similar potential energies, and almost same crystallization kinetics. [ In order to further investigate the crystalline structures of OBC-PE samples, the melting processes after nonisothermally crystallizing at four different cooling rates were characterized.…”