Synthesis of Branched Poly(butyl acrylate) Using the Strathclyde Method in Continuous-Flow Microreactors

Abstract

Solution polymerization of butyl acrylate and divinylbenzene (DVB) in toluene, initiated with 2,2′-azobisisobutyronitrile and mediated with chain transfer agent dodecanethiol (DDT), was carried out in a capillary microreactor with a 1 mm inner diameter. Through the Strathclyde method, branched poly­(butyl acrylate) with different molecular weight distributions (MWDs) was prepared by adjusting the feed formulation and the residence time. The dosages of DVB and DDT were controlled to avoid gelation, and their effects on the branching degree of the products were investigated. The multimodal MWDs were deconvoluted to quantitatively study the branching process. The kinetics in batch and continuous operation are compared. Aqueous miniemulsion polymerization with a similar feed formulation was also conducted in the microreactor, enabling faster reaction rate, lower solution viscosity, and higher branching efficiency. This study demonstrated the feasibility to use commercial monomers to prepare branched polymers with high functionality and a dense architecture in continuous-flow mode.

Integrating Biocatalysis with Viscous Deep Eutectic Solvents in Lab‐On‐A‐Chip Microreactors

“…[18,[30][31][32][33][34] When it comes to microreactors, the viscosity in the microchannels is a potential bottleneck since a high-viscosity solvent and clogging can raise the pressure. [35][36][37] Thus, the implementation of DES in these devices may be challenging, even at the reduced viscosities exerted by the DES-water mixtures. In that direction, some relevant efforts have been reported, for example, using ionic liquids-heptane in two-phase systems [38,39] for biocatalysis in microreactors.…”

“…When it comes to microreactors, the viscosity in the microchannels is a potential bottleneck since a high‐viscosity solvent and clogging can raise the pressure [35–37] . Thus, the implementation of DES in these devices may be challenging, even at the reduced viscosities exerted by the DES‐water mixtures.…”

Complex polymer architectures through free-radical polymerization of multivinyl monomers

“…37,38 This technique holds great industrial promise as a facile, pragmatic and cost-effective way to produce branched vinyl polymers using conventional FRP, especially so given later success demonstrated in aqueous emulsion, 38 solvent-free suspension 39 and continuous-flow reactors. 40 In addition to the traditional thiol based CTAs, catalytic chain transfer agentswere later used in a similar manner. 41 Given the reversible chain transfer feature of catalytic CTAs, the addition of a ppm level of bis [(difluoroboryl) dimethylglyoximato]cobalt(II) (CoBF) (Figure 3 I) was sufficient to massively suppress the intermolecular crosslinking and gelation, producing soluble branched polymers with monomer conversion over 90%.…”

Kinetic Modeling Study on the Preparation of Branched Polymers with Various Feeding Strategies

“…Tubular reactors represented by microreactors excel in spatial-temporal control and realize continuous production, appealing to industry. 21,22 We have successfully prepared hyperbranched polymers in a single-tube microreactor 23 and star polymers in a cascade microreactor system. 24,25 Due to better heat and mass transfer, the branching efficiency is higher in microreactors than in the batch, and tedious intermediate purification procedures are avoided.…”