Crystal structure and morphology of polyacrylonitrile in dilute solution

Abstract

The formation of spherulites from concentrated solutions of polyacryloiiit,rile (PAN) has previously been reported in this Journal.' It was shown

Solution-Grown Single Crystal of Polyacrylonitrile Polymerized by γ-Ray Irradiation on Urea-Acrylonitrile Canal Complex: Preparation and Preliminary Structure Analysis

“…Holland and his coworkers 8 insisted on the orthorhombic cell by analyzing the electron diffraction photographs of crystal mats with Table 1). Solution grown crystal mats, reported by Holland et al 8 and Klement and Geil 9 , were of ellipse shape and no distinct growing plane was observed. Therefore, these mats, in a strict sense, cannot be regarded as single crystals.…”

“…Although the crystal mats reported in literature for atactic PAN were heavily multilayered or agglomerated, Figure 1 indicates that highly isotactic PAN gives a single lamella if the polymer is isothermally crystallized under adequate conditions. Holland et al 8 and Klement and Geil 9 obtained elongated ellipse crystal mats for atactic PAN and the latter noted that it was no longer possible to detect the main original lamella. A solution-grown y-PAN crystal is a lozenge, with well-defined sides, closely associated with crystal growth faces.…”

Glass‐Transition Temperature (Tg) of Free‐Radically Prepared Polyacrylonitrile by Inverse Gas Chromatography, 2. Molecular‐Weight Dependence of Tg of Two Different Types of Aqueous Polymers

“…[1] Its molecular structure and various physical properties are quite complex. [2][3][4][5][6][7] The glass-transition temperature (T g ) is one of such complex properties. For example, the value of the T g of PAN varies across a wide temperature range (ca.…”

Glass‐Transition Temperature (Tg) of Free‐Radically Prepared Polyacrylonitrile by Inverse Gas Chromatography, 1. A Study on Tg of Atactic Monodisperse Polystyrenes

“…Also, the nature of the T g of PAN is not clearly understood, although various concepts have been presented, such as a hetero-bonded single phase, [1,2] a multi-order of transition, [3] and others. [4][5][6] In this article, as a preliminary study for the T g measurements of PAN, the T g of monodisperse polystyrene (PSt) was studied by an inverse gas chromatographic (IGC) analysis. Although this procedure is elaborate and time consuming, the T g value is clearly obtained as an inflection point from the Arrhenius-type plots.…”