Controlability Of The Molecular Weight Distribution To Tube Polymerization Process Through Periodic Feeding

In the paper, the research has been conducted on the periodic control of molecular weight distribution in tubular cationic polymerization which has been carried out through the periodic control of monomer feed. Controlling molecular weight distribution is of vital importance since it can affect the the mechanism and processability of the final product. There is a great need of both short chain length and long-chain length of polymer in industry for the short chain length can promote a higher processability of polymers, while the long chain length a more powerful mechanism.The main research work has been conducted as follows:A new method has been validated of controlling polymer molecular weight distribution. In the ideal situation, the process of the polymer production has been simplified through the treatment of the key parameters of the molecular weight distribution. Meanwhile, the feasibility of controlling molecular weight distribution through periodic operation of the monomer feed has been verified in theory.Modifications are adopted about the current tubular cationic polymerization models for the further research on periodic operation of the monomer feed's control on molecular weight distribution.Some constraint conditions have been studied about the parameters of periodic operation of the monomer feed which results in a more real cationic polymerization in a simulation mode. In these constraint conditions, the detailed influence of the periodic operation of the monomer feed on molecular weight distribution has been studied and analysed.The influence of the change of periodic monomer feed on molecular weight mixed distribution in a period has also been studied.Particle swarm calculation has been applied to perform optimization of molecular weight distribution. As a result, optimal periodic operation parameters have been acquired through iteration, which are greatly needed by expected molecular weight distribution.In conclusion, a research has been conducted about periodic control of molecular weight distribution following the steps of introducing control strategy of molecular weight distribution, verifying control strategy of molecular weight distribution and studying the detailed influence of the periodic operation of the monomer feed as well as attaining expected parameters of molecular weight distribution through optimization.