Method for preparing polyvinyl ether through cationic polymerization by adopting continuous flow method

Abstract

The invention provides a method for preparing polyvinyl ether through cationic polymerization by adopting a continuous flow method, which comprises the following steps: providing an injector A and an injector B, filling a cationic polymerization catalyst solution in the injector A, filling a vinyl ether monomer and an initiator solution in the injector B, and optionally comprising an additive; the method comprises the following steps: respectively connecting an injector A and an injector B to two injection pumps, controlling the flow rate of liquid through the injection pumps, injecting solutions in the injector A and the injector B into a mixer, mixing the solutions in the mixer, enabling the mixed solutions to flow into a tubular reactor, and carrying out cationic polymerization reaction while continuously flowing in the tubular reactor to obtain the product polyvinyl ether.

Description

technical field [0001] The present disclosure belongs to the field of polymer material synthesis, and in particular relates to a method for preparing polyvinyl ether by cationic polymerization using a continuous flow method. Background technique [0002] The stereoregularity of polymers has a very significant impact on the properties of polymeric materials, therefore, the stereoselective polymerization of various types of monomers has been extensively explored over the past few decades, for example, using chirality Metallocene catalysts perform coordination-insertion polymerization of alpha-olefins. However, these metallocene catalysts are usually easily poisoned by the polar groups on the monomers, resulting in catalyst deactivation. Subsequently, late transition metal catalysts have appeared for the polymerization of polar vinyl ether monomers, but these methods are difficult to achieve good stereoselectivity control. At this stage, many researchers use free radical poly...

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Problems solved by technology

However, these metallocene catalysts are usually easily poisoned by polar groups on the monomers, leading to catalyst deactivation.

Subsequently, late transition metal catalysts appeared for the polymerization of polar vinyl ether monomers, but these methods are difficult to achieve good control of stereoselectivity

At this stage, many researchers use free radical polymerization or cationic polymerization to polymerize vinyl ether monomers, which have great advantages in controlling polymer composition, molecular weight and molecular weight distribution. However, in terms of stereoselectivity still face great challenges

[0003] In the prior art, some catalysts are used to carry out cationic polymerization of vinyl ether at low temperature, but the obtained polymer is only about 70% isotactic

Although the isotacticity of the polymers prepared by some polymerization systems can reach about 90%, there is also the problem of the reverse correlation between the stereoselectivity of the polymer and the concentration of the monomer.

Based on these problems, the large-scale application of cationic polymerization of vinyl ethers is limited.

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