Dynamics in Poly(ϵ-Caprolactone) Containing Phase Separated Epoxy Thermosets

• Published in: Macromolecular materials and engineering Vol. 298; no. 12; pp. 1275 - 1281
• Main Authors: Lützen, Hendrik, Hartwig, Andreas
• Format: Journal Article
• Language: English
• Published: Weinheim Blackwell Publishing Ltd 01.12.2013; Wiley; John Wiley & Sons, Inc
• Subjects: Applied sciences; Chemical properties; Covalence; crystallization; epoxy resin; Exact sciences and technology; phase separation; polymer dynamics; Polymer industry, paints, wood; Polymers; Properties and testing; Technology of polymers; thermoset; toughness; Ring opening polymerization; Storage modulus; Epoxy resin; Mechanical properties; Cationic polymerization; Long term variation; Curing (plastics); Experimental study; thermoset; Morphology; Phase separation; crystallization; Mechanical loss; polymer dynamics; toughness; Polycaprolactone; Modified material
• ISSN: 1438-7492; 1439-2054
• DOI: 10.1002/mame.201200435

The dynamic phase separation of poly(ϵ‐caprolactone) (PCL) in cationically polymerized, cycloaliphatic epoxy thermosets is presented. While phase separation processes are commonly unknown from thermosetting polymers due to the covalently crosslinked polymer structure, the gradually occurring formation of crystalline ordered PCL domains is observed. The dynamic process is accompanied by a strong increase in the mechanical moduli and strengthening of the polymer due to the formation of finely distributed domains. Regarding the network and domain structure of the polymer during the dynamic process, the results show rearrangements mainly in the linear PCL segments driven by crystalline interactions without changes in the epoxy matrix polymer. Dynamic phase separation processes are shown in poly(ϵ‐caprolactone) containing epoxy thermosets. The formation of well distributed PCL‐domains in the highly crosslinked epoxy matrix is driven by gradually increasing crystalline interactions, leading to heterogeneous polymers. A strong increase in the mechanical properties is observed during the separation process.