Kinetics of the seeded semicontinuous emulsion copolymerization of methyl methacrylate and butyl acrylate

Modeling molecular weight distribution in emulsion polymerization reactions with transfer to polymer

“…5). Therefore, this confirms that with these concentrations of CTA, MWDs do not depend significantly on the monomer feed‐rate profiles and monomer concentrations in the polymer particles, as pointed out by Sayer et al77, 78 Again, very good agreement between the experimental and simulated distributions is attained.…”

Copolymerization of Biomass-Derived Carboxylic Acids for Biobased Acrylic Emulsions

“…Such a broad MWD confirmed that along with the chain transfer to the chain transfer agent, transfer to the polymer has also been the main termination event. 36 According to the GPC traces in Figure 4, the MWDs of both copolymers were in good agreement.…”

Closed-Loop Composition and Molecular Weight Control of a Copolymer Latex Using Near-Infrared Spectroscopy

“…This is believed to be due to the existence of mass-transfer resistance, which has not been accounted for during model formulation. As discussed in the literature, − this effect can be reduced if the monomer feed is pre-emulsified, which was not been performed on purpose to make the control targets more difficult to attain. As a consequence of the poor initial predictive capacity of the model, the controller is not able to avoid composition drifts in the very beginning of the reaction batch.…”

“…As discussed before, this fact can be attributed to the large gel content of the polymer material produced under starved conditions with a copolymer composition of 50% of MMA and BuA (molar basis). [31][32][33][34] Nevertheless, final agreement among the desired, experimental, and calculated number-average molecular weights can be regarded as excellent in both the open-loop and closed-loop cases. This is because the momentary interruption of the BuA feed flow did not cause a significant drift of the MWD of the polymer chains.…”

“…34 It is important to emphasize here that MMA/BuA emulsion copolymerizations can lead to the production of significant amounts of polymer gels and to very large polydispersion indexes. [31][32][33][34] This is caused mostly by very high chain-transfer rates to dead polymer chains that contain BuA. As a consequence, the weight-average molecular weight of polymer chains is subject to la arge uncertainty when obtained by typical GPC methods.…”