A kind of initiating method for acrylamide aqueous solution polymerization

Abstract

The invention discloses a method for initiating the polymerization of acrylamide aqueous solution. The acrylamide aqueous solution is made of acrylamide monomer, ionic monomer and deionized water. The method is to add a photoinitiator and multiple The azo initiators constitute a stepwise initiation system. After adjusting the pH value, pre-initiated by ultraviolet light, multiple azo initiators stepwise initiate polymerization to obtain polyacrylamide rubber blocks. The stepwise initiation system provided by the present invention: select initiators with corresponding half-lives at different initiation temperatures to provide an appropriate amount of free radicals for the reaction system to ensure that the polymer is extended in a linear structure, so that the synthesized product has lower residual monomers, The monomer conversion rate is high, the solubility is good, and the utilization rate is effectively improved. At the same time, the initiator is fully utilized within a suitable half-life period, which effectively saves the amount of the initiator; avoids delamination of the rubber block, makes the reaction more uniform, and the thickness of the rubber block It can reach 6-12 cm; the product will not have side reactions such as degradation, hydrolysis and cross-linking.

Description

technical field [0001] The invention relates to the field of high molecular polymer synthesis technology, in particular to an initiating method for acrylamide aqueous solution polymerization. Background technique [0002] The process of using chemical initiators to initiate polymerization of acrylamide polymers is relatively mature, but the product quality is unstable and the production cost is relatively high. Photoinitiated polymerization has the advantages of short polymerization time, high output, easy operation and control, low investment, environmental protection and energy saving, and the activation energy required for the reaction is low. It is a new high-efficiency process. However, the photoinitiated polymerization reaction also has disadvantages such as instability, many residual monomers in the product, many insolubles, and slow dissolution rate, which limit the scope of use of the product. [0003] The composite initiation system composed of a redox agent and a...

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Problems solved by technology

However, UV polymerization is only suitable for thinner systems. Usually, the thickness of the glue block is only about 5cm. If it exceeds 5cm, it will cause difficulties due to the decrease in light transmission.

In addition, the refraction of light by the bubbles generated during the polymerization process will cause a large difference in the light intensity between the upper layer and the lower layer of the rubber block. The gradient effect in the thickness direction of the rubber block is very obvious, and it is difficult to obtain a uniform polymerization product.