Thermoresponsive Microgels with High Loading of Zwitterions Exhibiting Superior Performance: A Macromonomer Approach

Abstract

In this investigation, the synthesis of temperature-responsive microgels containing high content of zwitterionic poly(phosphorylcholine) (PMPC) is reported. High loadings of polyzwitterionic chains are achieved by using PMPC-based "macromonomers," which are synthesized via a three-step reaction process. The first step involves synthesis of PMPC homopolymers via reversible addition fragmentation transfer (RAFT) polymerization, followed by end-group removal to generate reactive thiol groups, and last of all, introduction of polymerizable double bonds at the chain ends to provide PMPC-based macromonomers. Macromonomers of three different molar masses (3000, 5000, and 10 000 g mol −1 ) are used in three different molar ratios (1, 3, and 5 mol%) to synthesize microgels using N-vinylcaprolactam (NVCL) as the main co-monomer in precipitation polymerization. It is observed that the extent of total incorporation of the zwitterionic moiety is a function of both the macromonomer molar mass as well as its molar fraction in the feed which has a direct effect on their solution properties such as hydrodynamic radii and volume phase transition temperature (VPTT). Interestingly, these microgels show unprecedented extent of protein-repelling behavior owing to higher loading of zwitterionic moieties, what makes them interesting for the fabrication of protective coatings with anti-fouling properties.

Progress in process parameters and mechanism research of polymer emulsion preparation

“…2 The relationship between temperature and normalized absorbance of three large monomers: MG-5000-1M, MG-5000-3M, and MG-5000-5M. 29 conclusion, small monomers of acrylate are one of the important components of emulsion admixture. The synthesis pathway of acrylate is shown in Fig.…”

“…1 The relationship between normalized absorbance and temperature for three types of microemulsions: MG-3000-3M, MG-5000-3M, and MG-10000-5M. 29 Fig. 2 The relationship between temperature and normalized absorbance of three large monomers: MG-5000-1M, MG-5000-3M, and MG-5000-5M.…”

“…Chen Lunliang 28 investigated the synthesis of 77 different chain-length AB-type polystyrene macromolecular monomers using alkyne-PS-azide (l-PS-N3) as a model macromolecular monomer via the free radical polymerization mechanism (ATRP). Ganguly Ritabrata 29 achieved high-loaded polyzwitterionic chains based on poly(methyl methacryloyloxyethyl phosphorylcholine) polymer (PMPC) macromolecular monomers. Through a three-step reaction involving controlled radical polymerization (RAFT) polymerization, thiol group introduction, and polymerizable double bond introduction, PMPC-based macromolecular monomers were synthesized.…”

The Method of Direct and Reverse Phase Portraits as a Tool for Systematizing the Results of Studies of Phase Transitions in Solutions of Thermosensitive Polymers

“…A new synthesis was tested by Pich et al, which yielded stimuli-responsive PVCL microgels decorated with zwitterionic poly(sulfobetaine), poly(phosphobetaine), poly(carboxybetaine), or selenium-functionalized chains via reversible addition-fragmentation chain transfer (RAFT) precipitation polymerization [ 115 , 116 , 117 , 118 , 119 , 120 ].…”