aochengchem: Mechanism of coupling agent

Since the 1960s, scientists study the mechanism of coupling agent. Has made great progress, although not yet a consensus, but explained by chemical bond theory has been confirmed by a large number of experiments. R-Si-OR the type of coupling agent of different end group can react with polymers and fiber respectively to bond.By connecting two phase of the chemical bonds of interfacial bonding to improve.Tesla's research shows that deposition on the surface of the glass fiber, coupling agent usually contains components of physical and chemical adsorption of non-uniform layers, rinse with cold water to wash it by hydrogen bonding connection part of the coupling agent, wash with hot water can wash away with silica and the key connection body, at the end of the molecular layer, fiber with multiple key silica and silane coupling agent combined with very strong, it plays a main role to improve the interface bonding strength, and physical adsorption of the components is ineffective or even harmful.So the concentration of the coupling agent on the interface bonding can also have an impact, such as glass fiber in different concentrations of KH550 (gamma - ammonia propyl triethoxy silane) soaked in the solution after 10 min made sample, test results show that the coupling agent content was 0.4% ~ 0.4% (mass fraction) within the scope of the effect is best, in 8% of high content in the solution treatment effect is the worst.When coupling agent concentration is too low, the glass fiber on the adsorption capacity is insufficient, the concentration is too high adsorption in silane is arranged on the surface of the fiber mixed and disorderly, the corresponding physical adsorption layer thickening, unfavorable to interface bonding.