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Enhanced mechanical properties, thermal stability of phenolic‐formaldehyde foam/silica nanocomposites via in situ polymerization
Author(s) -
Li Qiulong,
Chen Lin,
Zhang Jinjin,
Zheng Kang,
Zhang Xian,
Fang Fei,
Tian Xingyou
Publication year - 2015
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.24169
Subject(s) - materials science , nanocomposite , thermal stability , in situ polymerization , fourier transform infrared spectroscopy , prepolymer , ultimate tensile strength , composite material , polymerization , friability , compressive strength , chemical engineering , polymer , polyurethane , ethyl cellulose , engineering
Phenolic foam (PF) displays excellent flame, smoke, and toxicity (FST) properties and good insulation properties. Nevertheless, the friability and inferior mechanical properties of PF have critically restricted its application in many fields. A series of phenolic foam/silica nanocomposites (MPF) with different silica contents were synthesized by in situ polymerization in this study. During the in situ polymerization process, the synthesis of phenolic resin/silica nanocomposites and formation of chemical bonding between the components were generated simultaneously. The reactive principle between silica nanoparticles and prepolymer was investigated using Fourier transform infrared spectroscopy (FTIR), and the results of FTIR indicated existence of the chemical reaction between them. Meanwhile, silica can act as “bridge” to form crosslinked network structure. The mechanical, thermal, and friability properties of MPF nanocomposites were characterized. Moreover, the results of microstructure of pure PF and MPFs indicated that the cell size distributions of MPFs are narrower, the cell distributions of MPFs are more uniform, and the cell wall thickness of MPFs is thicker, compared with pure PF. When the content of silica sol was 2 wt%, the compressive strength, compressive modulus, and tensile strength were increased by a factor of 47.37%, 38.55%, and 57.14% compared with that of pure PF, respectively. Furthermore, all MPF nanocomposites exhibited better thermal stability and lower pulverization ratio than that of pure PF. POLYM. ENG. SCI., 55:2783–2793, 2015. © 2015 Society of Plastics Engineers