Modification of high ortho novolac resin with diacids to improve its mechanical properties

To improve the brittleness of high ortho novolac resins, at first, high ortho novolac resins (N) were synthesized and condensation reactions between N and flexible diacids such as adipic acid (DA4) and azelaic acid (DA7) were carried out with different amounts of diacids, in the presence of zinc acetate as catalyst, in toluene as solvent. To characterize the diacid-modified resins (MN), FTIR analysis, TGA and DSC techniques were used. The morphologies of MN were also investigated. Moldings were prepared from the mixture of MN, fillers, and curing agent hexamethylenetetramine. Mechanical properties of these moldings were also determined. The results showed that high ortho novolac resin was toughened by the incorporation of flexible diacids in the polymer backbone and these modified resins can be used as a matrix resin of composite materials. (c) 2007 Wiley Periodicals, Inc

Blends and reaction products prepared from phenolic resins and waste pet. I. Mechanical properties

Blends or reaction products of novolac and resol type phenolic resins with waste poly(ethylene terephthalate) (PET) with up to 35% PET waste content, can after compression molding, yield composites with an interpenetrating network of phenolic matrix, supported by thermoplastic PET. Optimal amounts of waste PET improved the mechanical properties of the moldings, such as compression strength and hardness and, inmost cases, the strain to failure

Usage of the waste PET as filler in phenolic resins molds

The main aim in this work was to investigate usage of the waste PET powder as filler in "high ortho" novolac resin (N)-wood flour (WF) molds. At first, N was synthesized and then purified. The N after grinding to powder was mixed at different weight ratios (60, 80, and 95 %) with waste PET powder (WF-free). In addition, N was mixed 20 % with waste PET powder (with WF). The mixtures were molded to obtain test pieces in standard dimensions by Buehler Metaserv. Thus, we prepared molds from blends of novolac resin and waste PET powder. The effect of waste PET on the mechanical properties of the molds was investigated with mechanical measurements, such as compression strength, elastic modulus, strain to failure, and hardness. Using 20 % (wt) waste PET powder in the molds did not cause any significant change in compression strength, elastic modulus, strain to failure, and hardness values