Structure of polymer blends photo-cross-linked during the spinodal decomposition process

• Published in: Macromolecules Vol. 24; no. 7; pp. 1505 - 1510
• Main Authors: Tran Cong, Q, Nagaki, T, Yano, O, Soen, T
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.04.1991
• Subjects: Applied sciences; Crosslinking and degradation; Exact sciences and technology; Physicochemistry of polymers; Polymers and radiations; Structure processing relationship; Anthracene; Photochemical crosslinking; Morphology; Spinodal decomposition; Crosslinked polymer; Styrene polymer; Structure; Lateral group; Mixture; Dielectric relaxation; Chlorostyrene polymer
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma00007a011

Anthracene-labeled polystyrene/poly(2-chlorostyrene) blends (PSA /P2CS) with the composition 40/60 were photo-cross-linked during the time evolution of the spinodal-decomposition process. Photo-cross-links were carried out by utilizing the intermolecular photodimerization reaction between anthracene groups that were chemically attached on polystyrene chains. The structure and property of these photo-cross-linked blends were examined by means of optical microscopy and dielectric relaxation. It was found that, upon irradiation with a XeF excimer laser, the ordered structures resulting from a temperature-jump (T-jump) from the phase into the spinodal region were efficiently frozen. For a constant duration time of irriadation (5 min), the sizes of these ordered structures become larger as the blend was photo-cross-linked at a later time. Furthermore, the ordered structures revealed in these irradiated blends are different from those experiencing the same T-jump condition without irradiation. The corresponding maxima of the dielectric tan delta s of these irradiated blends shift toward the higher temperature side as the delay time of irradiation increases. Though only PSA chains were cross-linked, these ordered structures are thermally quite stable. Graphs, Photomicrographs. 23 ref.--AA