Transesterification in homogeneous poly(ε‐caprolactone)–epoxy blends

Transesterification has been investigated in poly(e-caprolactone) (PCL)–epoxy blends. In the hot melt process, the hydroxyl on diglycidyl ether of bisphenol-A (DGEBA) monomers is too low to give a noticeable transesterification reaction. In the postcure process, model reactions reveal that the hydroxyls from a ring-opening reaction are able to react with the esters of PCL. In the meantime, the PCL molecular weight decrease and its distribution becomes broader. Nuclear magnetic resonance spectra reveal that fraction of the tertiary hydroxyls converts to secondary hydroxyls. In the cured DGEBA–3,3′-dimethylmethylene-di(cyclohexylamine)–PCL blend, a homogeneous morphology is achieved. PCL segments are grafted onto the epoxy network after postcuring and result in the lower Tg observed in the differential scanning calorimetry thermogram. A higher transesterification extent also results in broader transition peaks by dynamic mechanical analysis. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 75–82, 1999

[1]  F. Chang,et al.  The Epoxy-Polycarbonate Blends Cured with Aliphatic Amine—II. Thermal and Mechanical Properties Mechanisms , 1997 .

[2]  F. Chang,et al.  The mechanism and model reactions of epoxy-polycarbonate blends cured with aromatic amine , 1997 .

[3]  Yiming Li,et al.  Rheological and mechanical properties of poly(butylene terephthalate)-modified epoxy resins , 1997 .

[4]  F. Chang,et al.  Mechanism of transesterification and cyclization of epoxy–polycarbonate blends catalyzed by quarternary ammonium salt , 1996 .

[5]  S. Sivaram,et al.  Aromatic polyesters via transesterification of dimethylterephthalate/isophthalate with bisphenol‐a , 1996 .

[6]  J. Pascault,et al.  Reaction-induced phase separation in poly(butylene terephthalate)-epoxy systems: 2. Morphologies generated and resulting properties , 1996 .

[7]  F. Chang,et al.  Chemical reactions, thermal and mechanical properties of epoxy — Polycarbonate blends cured with aromatic amines , 1996 .

[8]  F. Chang,et al.  Epoxy−Polycarbonate Blends Catalyzed by a Tertiary Amine. 1. Mechanism of Transesterification and Cyclization , 1996 .

[9]  M. Strumia,et al.  A study of the chelation behavior of heavy metal ions using a new synthetic support: PAS-GLUT , 1996 .

[10]  E. Rudnik,et al.  Liquid crystalline epoxy resins by polyaddition of aliphatic diepoxides with 4,4'-dihydroxybiphenyl , 1995 .

[11]  R. E. Robertson,et al.  Crystallization and thermoreversible gelation of poly(butylene terephthalate)–epoxy mixtures , 1994 .

[12]  Yih-Min Sun,et al.  Studies on the formation of PEN. I. Kinetic aspects of catalyzed reaction in transesterification of dimethylnaphthalate with ethylene glycol , 1994 .

[13]  R. E. Robertson,et al.  Preparation of small poly(butylene terephthalate) spheres by crystallization from solution , 1994 .

[14]  E. Amendola,et al.  Liquid-crystalline epoxy resins: curing of blends of mesogenic and non-mesogenic epoxy monomers , 1994 .

[15]  P. M. Adams,et al.  Synthesis and characterization of novel epoxy monomers and liquid crystal thermosets , 1993 .

[16]  C. Ober,et al.  The mechanical and magnetic alignment of liquid crystalline epoxy thermosets , 1992 .

[17]  George G. Barclay,et al.  Liquid crystalline epoxy thermosets based on dihydroxymethylstilbene: Synthesis and characterization , 1992 .

[18]  R. E. Robertson,et al.  Possible phase transformation toughening of thermoset polymers by poly(butylene terephthalate) , 1992 .

[19]  L. Chien,et al.  Side-chain liquid-crystal epoxy polymer binders for polymer-dispersed liquid crystals , 1992 .

[20]  R. E. Robertson,et al.  Toughening of thermoset polymers by rigid crystalline particles , 1992 .

[21]  I. Mondragon,et al.  Mechanical behavior of polycarbonate/phenoxy blends before and after interchange reactions , 1988 .

[22]  I. Mondragon,et al.  Exchange reactions on polyarylate-phenoxy blends: their influence on the physical and mechanical behaviour , 1987 .

[23]  J. Daly,et al.  Hydrogen bonding in epoxy resin/poly(ε-caprolactone) blends , 1984 .