Mesoscopic study of cylindrical phases of poly(styrene)-poly(isoprene) copolymer: Order–order phase transitions by temperature control

• Published in: Polymer (Guilford) Vol. 50; no. 19; pp. 4596 - 4601
• Main Authors: Rodríguez-Hidalgo, María-del-Rosario, Soto-Figueroa, César, Martínez-Magadán, José-Manuel, Luís-Vicente
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 10.09.2009; Elsevier
• Subjects: Applied sciences; Block polymers; Cylindrical structures; Exact sciences and technology; Order–order phase transitions; Organic polymers; Physicochemistry of polymers; Properties and characterization; Structure, morphology and analysis; Cylindrical structures; Block polymers; Order–order phase transitions; Computer simulation; Isoprene copolymer; Diblock copolymer; Temperature effect; Theoretical study; Composition effect; Order-order phase transitions; Phase transitions; Styrene copolymer
• ISSN: 0032-3861
• DOI: 10.1016/j.polymer.2009.07.026

Phase transitions of cylindrical structures of poly(styrene)–poly(isoprene) copolymer (PS–PI) toward spherical and gyroid structures were explored using DPD simulations and a coarse-grained model. Cylindrical phases were first obtained within a composition interval (“predominance region”) 0.2<fPS<0.26 (volume fraction of poly(styrene)). The predominance region of cylindrical structures was then subject to thermal heating cycles. The thermodynamic instabilities of cylindrical microdomains induce anisotropic composition fluctuations and phase transitions. A transition from the cylindrical phase at low composition limit to a spherical arrangement was observed during the thermal heating process. The cylindrical phase at the intermediate and high composition limit within the predominance region exhibits a transition towards a gyroid arrangement. The phase transition control during thermal heating on the cylindrical phases was governed by small variations in composition. The results are consistent with experimental studies. [Display omitted]