Synthesis process for ultra-branching nylon 6

Abstract

The process of producing super branched nylon-6 includes the following steps: the first compounding salt solution of dendritic polymer; the subsequent displacement and ring opening hydrolysis reaction first at 0.3-1.0 MPa and 200-220 deg.c for one period of time, then at 245-250 deg.c and 0.3-1.5 MPa for one other period of time and finally at normal pressure and 260-280 deg.c; and discharging to obtain the super branched nylon-6 product. The super branched nylon-6 melt has flowability 2-3 times that of common nylon-6 in similar mechanical performance and improved extrusion, spraying and forming performance for making nylon devices.

Description

technical field [0001] The invention relates to a synthesis method of hyperbranched nylon 6. Background technique [0002] At present, there are two urgent problems to be solved in the production and application of polyamide engineering plastics: (1) polyamide engineering plastics require high molecular weight, so they have high relative viscosity and small melt index; for subsequent injection molding and For extrusion molding, it is quite difficult to improve its filling quality and extrusion speed in the mold. For the production of narrow or thin parts or molded products with complex shapes, the impact of this defect on part yield is more prominent, such as the increase of glass fiber content in reinforced nylon, the increase of material tensile strength and flexural modulus , The shrinkage and warpage of processed products and parts become smaller, but its melt fluidity is poor, which will increase the processing time and cost. (2) For mixtures containing fillers or add...

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Problems solved by technology

[0002] At present, there are two urgent problems to be solved in the production and application of polyamide engineering plastics: (1) polyamide engineering plastics require high molecular weight, so they have high relative viscosity and small melt index; for subsequent injection molding and For extrusion molding, it is quite difficult to improve its filling quality and extrusion speed in the mold

For the production of narrow or thin parts or molded products with complex shapes, the impact of this defect on part yield is more prominent, such as the increase of glass fiber content in reinforced nylon, the increase of material tensile strength and flexural modulus , the shrinkage and warpage of processed products and parts become smaller, but its melt fluidity is poor, which will increase the processing time and cost

(2) For mixtures containing fillers or additives, due to the high relative viscosity and low melt index of polyamide, it is difficult to fill the mixture into the mold in a more uniform and sufficient manner and at a suitable speed, which also limits the additives. It is difficult to improve the dispersion due to the type of filler and the amount of filler used

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