Alkyl side chain length dependent compatibility of poly(4‐n‐alkylstyrene)s and 1,4‐rich polyisoprene blends

• Published in: Journal of polymer science. Part B, Polymer physics Vol. 55; no. 23; pp. 1791 - 1797
• Main Authors: Matsushima, Satoru, Takano, Atsushi, Matsushita, Yushu
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.12.2017
• Subjects: 1,4‐rich polyisoprene; anionic polymerization; blends; Compatibility; Lattice theory; Mathematical models; Mixtures; Optical microscopy; poly(4‐n‐alkylstyrene); Polyimide resins; Room temperature; Temperature; Temperature dependence; Thermodynamics; UCST
• DOI: 10.1002/polb.24428
• ISSN: 0887-6266

ABSTRACT We investigated the compatibility of blends of 1,4‐rich polyisoprene (1,4‐PI) and poly(4‐n‐alkylstyrene)s with six kinds of n‐alkyl side groups, that is, methyl, ethyl, propyl, butyl, hexyl, and octyl focusing on carbon number of alkyl groups. Poly(4‐methylstyrene)/1,4‐PI blend was turned out to be immiscible at all temperature range adopted in this work and poly(4‐ethylstyrene)/1,4‐PI blend revealed UCST type phase behavior, while the others were found to be compatible. The phase diagrams of poly(4‐ethylstyrene)/1,4‐PI blends were obtained by optical microscopy, and the temperature dependence of the Flory‐Huggins interaction parameter χ has been estimated to be χ = −0.036 + 24/T by applying lattice theory, where T is the absolute temperature. From this relationship χ value at room temperature (298 K) was calculated to be 0.045, the value is reasonably low for miscible polymers system. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1791–1797 Compatibility of 1,4‐rich polyisoprene and poly(4‐n‐alkylstyrene)s with six kinds of n‐alkyl groups—methyl, ethyl, propyl, butyl, hexyl, and octyl groups—were investigated by differencial scanning calorimetry and optical microscopy (OM). Phase diagrams of the blends of poly(4‐ethylstyrene) (n = 2) and 1,4‐rich polyisoprene with three different molecular weight were obtained by OM, and the Flory‐Huggins interaction parameter χ was estimated to be 0.045 at 298 K.