Acrylonitrile polymer aqueous phase suspension production system and method for PNA carbon fiber precursor

Abstract

The invention discloses a water-phase suspension production system and a water-phase suspension production method for an acrylonitrile polymer for a PNA carbon fiber precursor. The system is characterized by comprising a polymerizing pot, an overflow tank, a monomer recovery distillation column, a column bottom pump of the recovery distillation column, a polymerizing-emptying washer, a primary condenser of the monomer recovery distillation column, a secondary condenser of the monomer recovery distillation column, a vacuum system of the monomer recovery distillation column, a reflux tank of the monomer recovery distillation column, a reflux pump of the monomer recovery distillation column and a candle filter, wherein a plurality of material inlets are formed at the upper end of the polymerizing pot; the polymerizing pot is communicated with the polymerizing-emptying washer and the overflow tank respectively; the polymerizing-emptying washer and the overflow tank are communicated with the monomer recovery distillation column respectively; the monomer recovery distillation column is communicated with the candle filter by virtue of the column bottom pump of the recovery distillation column; the monomer recovery distillation column is communicated with the primary condenser of the monomer recovery distillation column; the primary condenser of the monomer recovery distillation column is communicated with the secondary condenser of the monomer recovery distillation column; the primary condenser of the monomer recovery distillation column and the secondary condenser of the monomer recovery distillation column are communicated with the reflux tank of the monomer recovery distillation column respectively; and the reflux tank of the monomer recovery distillation column is communicated with the monomer recovery distillation column and the polymerizing pot respectively. The produced acrylonitrile polymer has the advantages that the polymer slurry has high molecular weight, small dispersity and good stability.

Description

technical field [0001] The invention relates to a method for producing an acrylonitrile polymer, in particular to an aqueous suspension production system and method for an acrylonitrile polymer used for PNA carbon fiber precursors. Background technique [0002] Carbon fiber (carbon fiber, referred to as CF) is an inorganic polymer special fiber with a carbon content of more than 90%. Carbon fiber has high strength, high modulus, low density, small linear expansion coefficient, high temperature resistance and abrasion resistance in terms of physical properties. , soft and machinable characteristics, known as the king of new materials. Carbon fiber has been widely used in high-end civilian fields such as building materials, petrochemicals, machinery, electronics, marine development, transportation, and sports entertainment. It is a strategic material closely related to the national economy and national security. The special fibers urgently needed by fighter jets are also func...

AI Technical Summary

Problems solved by technology

[0011] At present, solution polymerization can only realize batch polymerization, but cannot realize continuous polymerization, so that the polyacrylonitrile precursor polymerization process is unstable, the dispersion of the precursor filaments (CV value) is large, and the quality of the polymerization stock solution varies from time to time, resulting in polyacrylonitrile The compositional drift of the precursor copolymer, wide molecular weight distribution, poor stability and poor batch repeatability have become a bottleneck for the development of carbon fiber in my country.

At the same time, due to the deficiencies in the polymerization process, core equipment, and control parameters in the water phase continuous polymerization, the molecular weight of the water phase continuous polymerization polymer hovers at a low level.

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