Modification Of Some Adhesive Materials

At present, with the development of science and technology, adhesive materials can be used widely in all fields, ranging from household furniture to aerospace. Adhesive materials can be used differently for different adhesives. There are many substances used for adhesive materials, such as:acrylic ester adhesives, polyurethane adhesives and ethylene-of vinyl acetate (EVA) type adhesives, epoxy resin adhesives and phenolic resin adhesives, and so on. According to the research and application needs, this paper mainly explore epoxy resin and polyurethane adhesives (polyurethane adhesives mainly exploring thermoplastic polyurethane (TPU) used for hot melt adhesive).Epoxy resin and TPU have a lot of advantages. Epoxy resin can resist high temperature, and have excellent mechanical properties and electrical insulation. TPU have good toughness, cold resistance, abrasion, oil and water resistant. Therefore, they can be used widely. But they also have some weakpoints, such as:epoxy resin is very crisp, and can’t resist water, TPUs’price is high, so it fails to be accepted in many occasions, which hampered their widespread application. After understanding the functional groups’basic application, this paper modified these two kinds of adhesive as follows:(1) Choosing hydroxyterminated silicone oil and hexamethylene-1,6-diisocya-nate(HDI) which have flexible chain segment modified epoxy resin, cleverly using two activity groups in the molecular chain of epoxy resin reacted with hydroxyl in the molecular chain of silicone oil and isocyanate in the molecular chain of HDI, we can get different properties’resins,such as:hydroxyterminated silicone oil modified epoxy resin, HDI modified epoxy resin and hydroxyterminated silicone oil/HDI modified epoxy resin. The research show that Si-O-Si in the molecular chain of hydroxyterminated silicone oil can improve mechanical properties, thermal properties and hydrophobic of the epoxy resin. Getting carbamate ester groups from-NCO in the molecular chain of HDI reaction with-OH in the molecular chain of epoxy resin can improve the mechanics properties of epoxy resin.(2) We choose two different epoxy resin’s curing agents for application needs, (polyamide, colorless transparent liquid curing agent which constitute form Methyl hexahydrophthalicanhydride and Tetrabutyl ammonium bromide). This two curing agents react with epoxy group in epoxy resin, make the resin cross-linked and cured. The research show that, polyamide curing agent is a common and convenient curing agent; Getting colorless transparent curing product from colorless transparent liquid curing agent, can be used in optoelectronic devices for protecting the devices, without any affecting to devices’transmittance.(3) Choosing nano-materials blending into modified epoxy resin and TPU, using of its size effect, under the condition of not changing the material basic properties of modified epoxy resin, we can improve thermal stability and hydrophobic, and reduce the cost of hot melt adhesive TPU.(4) We choose polyvinyl chloride (PVC) as hot melt adhesive’s mixtures, because PVC is cheap and its mechanical performance is good. The cost of hot-melt adhesive can be reduced while it is mixed with a certain amount of PVC; The mechanical properties of the hot-melt adhesive film can be improved while it is added plasticizer Dioctyl phthalate (DOP).