Synthesis and structure evolution of phenolic resin/silicone hybrid composites with improved thermal stability
Phenolic resin/silicone hybrid composites (MPR) were prepared by a facile and low-cost method. FTIR results show that polycondensation of siloxane occurs in the presence of catalyst and water in the system, and siloxane oligomer was formed. During the curing process, the transesterification reaction between siloxane oligomer and phenolic resin (PR) makes silicon incorporated into PR. The TGA results indicate that introducing Si–O structure into PR can effectively improve the thermal stability of the resin. Compared with cured neat PR, temperatures at 5 and 10% mass loss of cured MPR can be improved by 43 and 36 °C. Its char yield at 800 °C was increased by about 9.1%. Cured MPR has been characterized by FTIR, XPS, XRD and Raman spectra to discuss the chemical state changes of silicon during pyrolysis process, as well as the effect of silicon on the char yield. On the one hand, the formation of Si–O–C structure can reduce the number of phenyl hydroxyl groups, which contributes to the reduced weight loss. On the other hand, the results indicate that Si–Ox structure was formed from the oxidation of Si–CH3 and hydrolysis of Si–O–C structures. According to Raman analyses, introducing silicone into the system cannot help to promote the formation of a more ordered structure. Additionally, the mechanical properties of cured MPR have also been improved.
This research is supported by Science and Technology Fund and Sponsored by the Seed Foundation of Innovation and Creation for Graduate Students in Northwestern Polytechnical University (No. Z2017046) and Shanghai Aerospace Science and Technology Innovation Fund (No. SAST2017-121).
Compliance with ethical standards
Conflict of interest
The authors declare that there is no conflict of interest for this manuscript preparation and publishing.
- 4.Pilato LA, Koo JH, Wissler GA, Lao S (2008) A review-phenolic and related resins and their nanomodification into phenolic resin FRP systems. J Adv Mater 40:5–16Google Scholar
- 31.Kobera L, Czernek J, Strečková M, Urbanova M, Abbrent S, Brus J (2015) Structure and distribution of cross-links in boron-modified phenol-formaldehyde resins designed for soft magnetic composites: a multiple-quantum 11B–11B MAS NMR correlation spectroscopy study. Macromolecules 48:4874–4881CrossRefGoogle Scholar
- 37.Chen X, Ye J, Yuan L, Liang G, Gu A (2014) Multi-functional ladder-like polysiloxane: synthesis, characterization and its high performance flame retarding bismaleimide resins with simultaneously improved thermal resistance, dimensional stability and dielectric properties. J Mater Chem A 2:7491–7501CrossRefGoogle Scholar
- 49.Parker JA, Winkler EL (1967) The effects of molecular structure on the thermochemical properties of phenolics and related polymers, NASA TR R-276. Washington, DCGoogle Scholar
- 52.Ouchi K, Honda H (1959) Pyrolysis of coal 1. Thermal cracking of phenol-formaldehyde resins taken as coal models. Fuel 38:429–443Google Scholar
- 62.Wang S, Wang Y, Bian C, Zhong Y, Jing X (2015) The thermal stability and pyrolysis mechanism of boron-containing phenolic resins: the effect of phenyl borates on the char formation. Appl Polym Sci 331:519–529Google Scholar