Production process flow of polymethyl methacrylate
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I have just started working with the production of polymethyl methacrylate, and I am not familiar with the process flow and reaction control involved in producing it using the low-temperature suspension polymerization method. Could some seniors with such experience recommend ways to learn and master the relevant knowledge more quickly? It would be better if a flowchart showing the relevant control points could be provided, haha... A brief overview is as follows: 1. Preparation of the continuous phase – the continuous phase refers to the aqueous phase; first, the dispersant is added to water. 2. Preparation of the dispersed phase: The dispersed phase is the monomer phase, to which additives such as initiators are added. 3. Suspension polymerization: The aqueous phase and the monomer phase are added to the polymerization reactor, along with a molecular weight control agent; thereafter, stirring is started and the temperature is raised to 90–95°C, at which point polymerization begins. Since the polymerization process is an exothermic reaction, cooling is achieved through the circulation of water at a certain temperature in the jacket, but it is necessary to maintain the temperature for complete polymerization. Polymerization time is 2 hours, with a conversion rate of 96%. 4. Polymer slurry treatment: The slurry taken out of the polymerization tank is first filtered through a filter screen to remove any agglomerated clumps in the polymer, after which it is sent to a washing tank for cleaning, with circulation being achieved using a slurry pump ； Some of the slurry is continuously transferred to a separator to separate the polymer from the mother liquor, while the water-containing polymer is fed into a centrifuge to further separate the polymer from the mother liquor. 5. Drying: The wet material falls from the centrifuge into a screw conveyor and is then sent to an air-flow dryer. After drying with hot air, it is sent to a cooler where it is cooled until sticking does not occur during storage. 6. Screening and packaging: The cooled material is then screened, resulting in polymer beads with an average size of about 30 mm, which are placed into packaging bins for packaging.
PMMA is a good downstream derivative, and its use in high-end applications is increasing year by year; it’s definitely worth paying attention to. However, what the original poster is looking for may involve core technologies, haha – I’m afraid not many people will be able to provide that.
The technical level of PMMA in China is quite far behind that of advanced regions such as the United States, Japan, and Europe. Regarding polymerization reaction technology, a sufficiently rigorous and comprehensive R&D system has not been established in China, resulting in significant instability in the precise control of the technology. Improvements are needed in several key areas: 1. Initiator screening technology ； 2. Refining technology for polymer-grade raw material monomers ； 3. Polymerization theory research and molecular structure research ； 4. Polymer property testing techniques and experimental apparatus ； 5. A well-developed talent pipeline and a lack of dedication. Polymer production is a highly complex process; once the polymerization reaction begins, it is essentially impossible to control it until a terminator is added or the reaction comes to an end on its own. There are many design aspects involved, as well as numerous uncertainties, requiring careful verification and repeated testing to optimize the process. Strive for stable and consistent batch quality. Without strict process control and proper personnel oversight, it’s difficult for just one or two people to achieve high levels of technical expertise, haha. These are just my personal opinions; feel free to criticize them.