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Synthesis and prperties of peroxy derivatives of epoxy resins based on Bisphenol A. 1. Effects of the presence of inorganic bases
Author(s) -
Bratychak Michael,
Brostow Witold
Publication year - 1999
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.11547
Subject(s) - epichlorohydrin , epoxy , diglycidyl ether , oligomer , bisphenol a , acetone , solvent , polymer chemistry , bisphenol , chemistry , materials science , organic chemistry
Oligomers containing peroxy groups have been synthesized from epoxies and aliphatic and aromatic hydroperoxides. The dependence of reaction rates upon ratios of starting materials, the presence of an inorganic base as a catalyst, nature of solvent, quantity of water, and temperature have been investigated. The hydroperoxide + epoxy reactions proceed very slowly in the presence of NaOH but at satisfactory rates in the presence of KOH. The reactions do not proceed in acetone, methylethylketone, dioxane, or toluene, but do proceed in secondary and tertiary alcohol media. We have studied in particular the reaction between tert ‐butyl‐hydroperoxide (tBHPO), diglycidyl ether of diphenylpropane and an epoxy resin based on Bisphenol A and epichlorohydrin. Structures of the products were confirmed by IR and 1 H‐NMR spectroscopy. Mechanisms of reactions have been defined and an empirical equation that describes kinetics of the reaction between tBHPO and the epoxy has been developed. The peroxy oligomers so obtained were used to create networks based on a polyesteric resin. Going from 10 wt% of the peroxy oligomer to 25% increases significantly the rate of gelation as well as the final gel weight fraction. However, a further increase of the peroxy oligomer concentration to 50% affects only slightly the gelation kinetics and the plateau gel fraction.