Simultaneous multiple sample light scattering detection of LCST during copolymer synthesis

McFaul, Colin A.; Alb, Alina M.; Drenski, Michael F.; Reed, Wayne F.

doi:10.1016/j.polymer.2011.08.026

Cited by 11 publications

(5 citation statements)

References 51 publications

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“…The molecular weight can be simultaneously controlled by the total rates of A and B feed, where p can now be a function of instantaneous comonomer concentrations and can also be recomputed if and as it changes during copolymerization. ACOMP has been used extensively for monitoring copolymerization reactions, − so that the underlying methodology needed to provide composition information to the copolymerization controller already exists.…”

Section: Discussionmentioning

confidence: 99%

Automatic Control of Polymer Molecular Weight during Synthesis

McAfee

Leonardi²,

Montgomery³

et al. 2016

Macromolecules

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The continuous record of monomer and polymer concentrations, C m and C p , and cumulative weight-average mass, M w , furnished by automatic continuous online monitoring of polymerization reactions (ACOMP) has been harnessed to provide feedback to control reactor monomer flow in order to follow a target trajectory M w,t (t) during linear chain growth free radical polymerization. This was achieved without a detailed kinetic model. Two proportionality parameters to pilot the controller, α and p, result from (i) reaction rate = αC m and (ii) M w,inst = pC m , where M w,inst is instantaneous M w . Using Ansatz values for α and p, the controller periodically recomputes these, based on the ACOMP data stream, in order to follow M w,t (t). A histogram of concentration vs M w,inst estimates the molecular weight distribution width. Invoking an instantaneous distribution provides polydispersities. Results are compared to GPC analysis on end products. The concept of "isomorphic reaction pair" is introduced: two reactions that follow the same trajectory under different reaction variables, e.g., varying T at constant [initiator] and varying [initiator] at T = constant. The controller can be used, as is, for high solids reactions, and extended to copolymerization, including for possible control of composition gradients in controlled radical polymerization.

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Section: Discussionmentioning

confidence: 99%

Automatic Control of Polymer Molecular Weight during Synthesis

McAfee

Leonardi²,

Montgomery³

et al. 2016

Macromolecules

Self Cite

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“…Triethylammonium hypophosphite was prepared from triethylamine and hypophosphinic acid in toluene. The diblock copolymer NS was prepared as previously reported [ 45 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ]. Dialysis was performed using Spectra/Por ® RC tubing (MWCO: 3.5kD).…”

Section: Methodsmentioning

confidence: 99%

Palladium-Catalyzed Mizoroki–Heck and Copper-Free Sonogashira Coupling Reactions in Water Using Thermoresponsive Polymer Micelles

et al. 2021

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A few kinds of thermoresponsive diblock copolymers have been synthesized and utilized for palladium-catalyzed coupling reactions in water. Poly(N-isopropylacrylamide) (PNIPAAm) and poly(N,N-diethylacrylamide) (PDEAAm) are employed for thermoresponsive segments and poly(sodium 4-styrenesulfonate) (PSSNa) and poly(sodium 2-acrylamido-methylpropanesulfonate) (PAMPSNa) are employed for hydrophilic segments. Palladium-catalyzed Mizoroki–Heck reactions are performed in water and the efficiency of the extraction process is studied. More efficient extraction was observed for the PDEAAm copolymers when compared with the PNIPAAm copolymers and conventional surfactants. In the study of the Sonogashira coupling reactions in water, aggregative precipitation of the products was observed. Washing the precipitate with water gave the product with satisfactory purity with a good yield.

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“…The most well-known example of polymerizations is the so-called ACOMP system. 286,287 ACOMP (automatic continuous online monitoring of polymerization) performs continuous sample withdrawal and dilution from a reactor into a tiny stream of reactor fluid that passes through a number of inline detectors, primarily a refractometer (RI), ultraviolet absorbance spectrometer (UV), time-dependent static light scattering (TDSLS) device, and perhaps also a viscometer, to perform online monitoring of the absolute weight-average molecular weight of the polymers. Comparative measurements of monomer conversions were made using in situ NIR and the ACOMP detection train, and they showed good agreement.…”

Section: Polymer Chemistry Reviewmentioning

confidence: 99%