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Benzoxazine–epoxy copolymers: effect of molecular weight and crosslinking on thermal and viscoelastic properties
Author(s) -
Rao BS,
Rajavardhana Reddy K,
Pathak Sandeep K,
Pasala AR
Publication year - 2005
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.1853
Subject(s) - differential scanning calorimetry , epoxy , copolymer , materials science , dynamic mechanical analysis , tetrabromobisphenol a , curing (chemistry) , viscoelasticity , bisphenol a , exothermic reaction , composite material , polymer , char , dynamic modulus , glass transition , polymer chemistry , chemical engineering , pyrolysis , chemistry , organic chemistry , thermodynamics , fire retardant , physics , engineering
Bisphenol‐A‐based benzoxazine was copolymerized with epoxy and chain‐extended epoxies in order to study the effect of molecular weight on cured resin properties. Cure behaviour of the copolymers was studied using differential scanning calorimetry, which indicated a single exothermic curing peak at 248 °C. Dynamic mechanical thermal analysis was used to study the viscoelastic properties of the cured resins. A decrease in tan δ peak position and an increase in storage modulus and tan δ peak height were observed due to chain extension. Higher char yield was observed for the copolymer chain extended with tetrabromobisphenol‐A. Copyright © 2005 Society of Chemical Industry