Improvements relating to polymerisation reactions

Abstract

A method of conducting polymerisation reactions on a rotating surface reactor which allows substantially increased conversions (up to around 99%) to be achieved without a corresponding increase in polydispersity as would be expected as a result of the Trommsdorff-Norrish effect. The rotating surface reactor serves to disentangle and / or stretch growing polymer chains so as to result in better control over polymerisation kinetics.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This is a continuation of U.S. patent application Ser. No. 10 / 484,611, filed Jan. 20, 2004, which entered the U.S. National Stage from PCT Application No. PCT / GB02 / 03341, filed Jul. 22, 2002, which application claimed priority to Great Britain Patent Application No. GB01117642.9, filed Jul. 20, 2001. Each of the above applications are incorporated herein by reference. Priority of each of the above-referenced application is hereby claimed.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not applicable REFERENCE TO A “MICROFICHE APPENDIX”[0003] Not applicable BACKGROUND OF THE INVENTION [0004] The present invention relates to methods for enhancing the kinetics of polymerisation reactions, and in particular to methods for achieving high rates of polymerisation and narrow molecular weight distribution, advantageously even at high molecular weights (for example up to 400,000 or above) and at high intrinsic viscosities (...

AI Technical Summary

Problems solved by technology

This means that there is little control over the precise reaction kinetics, since polymerisation initiation can occur at different times in different regions of the reactor volume.

Although mixing within the reactor vessel can help to reduce this problem, such mixing can in fact complicate the reaction kinetics even further.

However, current reactors adapted for plug flow processes have a number of disadvantages, including low surface area to volume ratios, no draw, low shear and high pressure drops at higher conversions.

This prior art reference does not provide any teaching as to how such polymerisation reactions can be controlled to give tight molecular weight distributions, nor does it demonstrate any detailed disclosure of how the use of a spinning surface can be adapted specifically for polymerisation reactions.

A limiting factor in terms of polymer conversion on the surface is the viscosity of the prepolymer and / or polymer mix.

Research by the present applicant indicates that conditions on a rotating surface reactor may contribute to a reduction in cage effects which would normally result in low initiator efficiency.

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