The effect of in situ‐formed copolymers on the morphology of reactive poly(phenylene ether)/poly(amide‐6) blends. Issue 9 (14th March 2020)

• Record Type: Journal Article
• Authors: Moyses, Stephan; Ramakrishnan, Vaidyanath; Lietzau, Christian; Bajaj, Pooja
• Is Part Of: Journal of polymer science. Volume 58:Issue 9(2020)
• Page Start: 1262
• Page End: 1275
• Publication Date: 2020-03-14
• Subjects: block copolymer -- immiscible blend -- surface tension -- DSC -- Chemo‐rheology -- reactive blending; Polymers -- Periodicals; Polymerization -- Periodicals; Polymerization; Polymers; Periodicals; 547.7
• DOI: 10.1002/pol.20200017
• Languages: English
• ISSNs: 2642-4150

Abstract

Abstract: Poly(phenylene ether) (PPE)/poly(amide‐6) (PA6) blends are examined in light of the information provided by two‐dimensional chromatography and chemorheology. Chromatography provides a snapshot of the blend composition in the finished material, while rheology presents us with a direct insight into the reactions taking place in the melt. Block copolymer formation is chromatographically confirmed for the blends prepared with a coupling agent, but also for the blend prepared without any coupling agent. No co‐continuous morphology is observed by scanning electron microscope. Instead, a coarse structure of PPE droplets in the PA6 matrix is obtained for the blend prepared without coupling agent. This is explained by the combined effects of the low viscosity of PA6 and the inherently formed copolymers. The PPE domains are smaller in the blends prepared with the coupling agents. Their size is correlated with the copolymer formation, surface tension, and interphase relaxation time. The data evidence a complex system where reactions resulting in the formation of copolymer via coupling or grafting take place together with the extension of the PPE and condensation growth of the PA6 polymers. Abstract : The in situ formation of a block copolymer in an immiscible blend and its effect on the morphology of the resulting material is examined for the poly(phenylene ether)/poly(amide‐6) system. Copolymer formation is confirmed by chromatography. The viscoelastic properties of the material indicate a dynamic system where reactions involving chain coupling, grafting, extension, and growth take place.