Preparation Of Nylon6by Oil Phase Suspension Polymerization And Study On Structure And Properties

This paper adopts the mechanism of anionic polymerization, preparing the finegranular nylon6resin by the method of oil phase suspension polymerization, withliquid caprolactam as the dispersed phase, NaOH as the initiator, TDI as activator,dimethyl silicone oil as the continuous phase. The method shows advantages of highpolymerization speed, low polymerization temperature, and high relative molecularweight, etc. In addition, compared with the traditional casting nylon, polymerizationprocess conditions are easy to control, and the product can be directly used forsecondary processing molding, such as in extrusion, injection molding.By exploring the polymerization reaction conditions, especially in-depth studyfor the influential factors of polymerization conversion and polymerization productrelative viscosity, via a large number of experiments, finally we get more suitablepolymerization conditions. The initiator dosage is0.55%monomer mole ratio, andthe activator dosage is0.32%monomer mole ratio. The time of vacuum-pumping is30minutes for melted caprolactam. The time of vacuum-pumping is30minutesafter adding base. Polymerization process is anhydrous at140℃for50min. Faintyellow fine granular products are obtained, and the relative viscosity is4~4.5, thepolymerization conversion is30%~35%.The structure, thermal properties, crystallization properties and mechanicalproperties of characterization of the oil phase suspension polymerization productsare tested by Fourier transform infrared analyzer (FTIR), differential scanningcalorimetry (DSC), thermal gravimetric analyzer (TG), X-ray diffraction (XRD),universal testing machine and impact testing machines and other means of detection.By analysis the differences of the products with the ordinary nylon6and castingnylon6, The oil phase suspension polymerization of nylon6has a low melting point,low crystallinity. The tensile strength has a slight decrease, but it has a high impactresistance, notched impact strength is38.6%higher than the MC nylon. Theproducts show better overall performance.