Fabrication And Study Of Self-emulsifying Epoxy Curing Agent And Epoxidized Novolac Resin Base On Cardanol

As the industry developed, various industrial products have permeated through all aspects of social life. Since technology and economy is historically limited during the process of manufacture and consumption, some industrial products are tended to be biological hazard, such as solvent-based epoxy coating. Potentially danger and environmental pollution due to the use of a large amount of solvent during the production and construction process of solvent-based coatings are being concerned. The low molecular weight polyamines, curing agents, are toxic. Raw materials, such as bisphenol A, also known as environmental hormone, are hazardous. In this article, research works involve the two following aspects:1. Preparation and characterization of nonionic self-emulsifying cardanol-based curing agent.2. Preparation and characterization of cardanol-based epoxidized novolac resin.An eco-friendly self-emulsifying epoxy curing agent was prepared by using polyethylene glycol (PEG) as hydrophilic segment to emulsify Mannich base, which prepared by cardanol, polyamine and formaldehyde. In this paper, cardanol-based Mannich bases (MA) reacted with Epoxy terminated polyethylene glycol (EP) and γ-glycidoxy propyl trimethoxy silane (GPTMS) at different mass ratios, temperatures and reaction time to produce self-emulsifying curing agent, named EPMA. MA was prepared by reacting cardanol with formaldehyde and different polyamines. EP was prepared by reacting different molecular weight of polyethylene glycols with epoxy resin at different molar ratios. MA, EP and EPMA were characterized by FTIR,’H-NMR and13C-NMR spectroscopic methods for their structure elucidation, and gel permeation chromatography for determining their molecular weights. The most suitable EP were prepared by PEG6000and epoxy resin at the molar ratio of1:2. EPMA was prepared by MA and different amount of EP at70℃for60min. The coatings of EPMA and waterborne epoxy resin own reasonably pot life, good physical and corrosion resistance properties. The main value of this work is the preparation of an eco-friendly self-emulsifying curing agent by using a low-cost natural renewable material,cardanol. Combining the advantages of Mannich base, cardanol and waterborne technology. EPMA is a good curing agent with reasonable properties.A kind of renewable, abundant and low-cost bio-based material-cardanol was used to prepare a modified epoxidized novolac resin (ECN) by reacting epichlorohydrin and novolac (CN) in the presence of alkali as catalyst; CN was prepared by reacting cardanol and formaldehyde in the presence of acid as catalyst. The resin (ECN) structure was characterized by FTIR and NMR. Molecular weight of ECN was characterized by GPC. The performances of the curing films, which was hardened by IPDA and the mixtures of E51and ECN. were tested. The result showed that addition of ECN can improve the adhesion, flexibility and impact resistance of films remarkably without reducing the hardness.