Novel silicon-modified phenolic novolac resins: Non-isothermal curing kinetics, and mechanical and thermal properties of their biofiber-reinforced composites

A silicone-contained biphenol type monomer, 4,4'-(1,3-dipropyl-tetramethyldisiloxane)bis-2-methoxyphenol(SIE), was used to modify phenolic novolac resin by being copolymerized with phenol and formaldehyde to yield SIE-modified phenolic resins (SPNs). The curing behavior of SPNs with hexamethyleneteramine (HMTA) was analyzed by DSC tests, and the non-isothermal curing kinetics were analyzed using the model-fitting and model-free isoconversional methods. Then, SPN/HMTA was used as the resin matrix, while surface-treated chopped sisal fiber was used as the reinforced filler to produce the silicon modified phenolic molding composites (SIEC). The finished composites expressed improved mechanical and thermal resistance properties compared with unmodified composites. (C) 2013 Elsevier B.V. All rights reserved.