Are there two termination methods for producing polyvinyl chloride by suspension method?
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One uses a water-phase terminator, and the other uses an oil-phase one. Is that the case? This post was last edited by wang*neng on 2009-3-9 08:33]
Common terminators used in the suspension method for producing polyvinyl chloride include bisphenol A, ATSC (propylthiouronium acetate), and NO. These terminators are employed in different situations: bisphenol A is used as a regular terminator, NO serves as an emergency terminator, while ATSC can be used in both cases. As for the terms aqueous phase or oil phase, no references were found in the relevant literature.
Yesterday, I heard a professor from the School of Chemical Engineering say that it mainly depends on whether the additive used before polymerization is of the aqueous or oil-based type (I didn’t hear that very clearly). However, he said that currently, water-phase type terminators are used more frequently.
It is usually divided into two types: normal termination agent addition and emergency termination agent addition. The addition of an emergency terminator usually occurs in two situations: in an emergency, it is added manually by the operator (by the operator pressing a designated button) ； Or it can be automatically detected and activated through a third-party system (ESD/PLC). It depends on which patent technology is used. ）
ls refers to the joining method. It’s not the termination method mentioned by lz
Currently, manufacturers mostly use water-soluble terminators, whose advantage is that they distribute rapidly throughout the system and quickly terminate the reaction.
Common terminators used in the suspension method for producing polyvinyl chloride include bisphenol A, ATSC (propylthiouronium acetate), and NO. These terminators are employed in different situations: bisphenol A is used as a regular terminator, NO serves as an emergency terminator, while ATSC can be used in both cases
There are three types of suspension polymerization terminators: gas-phase terminators, emergency terminators, and end-point terminators.
This post was last edited by limingshuguang on 2009-7-9 21:25. Terminators are generally divided into two categories: regular terminators and emergency terminators. Vapor-phase terminator? Haven’t heard of it. Could you give an example? As for the aqueous phase and the oily phase, it should be a matter of choosing the solvents.
ATSC is primarily used. At present, most terminators are toxic, and there is a gradual shift towards the use of non-toxic terminators
Currently, there are mainly these three types; ATSC is used the most, while NO is only used as a backup in case stirring needs to be stopped
Termination agents do come in water-phase and oil-phase types; those used in the water phase are chosen because the solvents are inexpensive. The effectiveness of termination is related to the concentration of the termination agent, and manufacturers generally purchase termination agents to prepare them themselves in order to ensure optimal termination results. Otherwise, the concentration of the pre-made terminator may not be sufficient, and the termination effect cannot be guaranteed.
The original poster is right; among water-phase terminators, there are further two types: water-based and water-emulsion type. Water-based terminators are not subjected to emulsification treatment and are typically water-soluble; those with water-emulsion properties have undergone specialized emulsification treatment, resulting in finer particles and more uniform termination.