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High‐ T g , heat resistant epoxy–silica hybrids with a low content of silica generated by nonaqueous sol–gel process
Author(s) -
Ponyrko Sergii,
Kovářová Jana,
Kobera Libor,
Matějka Libor
Publication year - 2014
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.40899
Subject(s) - epoxy , thermal stability , materials science , sol gel , chemical engineering , interphase , dynamic mechanical analysis , hybrid material , thermogravimetric analysis , thermal analysis , modulus , silica gel , composite material , polymer chemistry , polymer , thermal , nanotechnology , biology , engineering , physics , meteorology , genetics
The epoxy‐silica hybrids showing high T g and thermal stability are prepared by the non‐aqueous sol–gel process initiated with borontriflouride monoethylamine. Tetramethoxysilane (TMOS) is used as a precursor of silica and 3‐glycidyloxypropyl trimethoxysilane as a coupling agent to strengthen the interphase interaction with an epoxy matrix. The basic factors governing the nonaqueous sol–gel process are studied in order to reveal the formation–structure–properties relationships and to optimize the hybrid composition as well as conditions of the nonaqueous synthesis. The formation of the hybrid, its structure, thermomechanical properties and thermal stability are followed by chemorheology experiments, NMR, DMA and TGA. The most efficient reinforcement of the epoxy network is achieved by the combination of both alkoxysilanes, showing synergy effects. The hybrids with a low content (∼10 wt %) of the in situ generated silica exhibit dramatic increase in T g and the high modulus, 335 MPa, up to the temperature 300°C. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40899.