Estimation of Reactivity Ratios in the RAFT Copolymerization of Styrene and Glycidyl Methacrylate

Abstract

the advantages of undemanding condition requirements and the ability to polymerize a large number of monomers. The disadvantage of this method is poor control in both molar mass and polymer microstructure of the product.Reversible deactivation radical polymerization (RDRP) or controlled radical polymerization (CRP) techniques have received a great deal of attention because of their ability to generate materials with well-defined molar mass and microstructures. Such products include a great variety of polymers synthesized from functional monomers, which could not be created by living anionic polymerization without stringent requirements. The main CRP techniques, nitroxide-mediated polymerization (NMP), [7] atom transfer radical polymerization (ATRP), [8] and reversible addition-fragmentation chain transfer (RAFT), [9] have provided access to functional polymers with targeted molar mass, narrow molar mass distributions, and defined molecular microstructures. These properties were once thought impossible to obtain via free-radical technology.The RAFT technique is probably the most versatile of those mentioned, because it can be used with a wide range of functional monomers bearing a reactive side group (hydroxyl, carboxyl, amino, etc.), and is tolerant of water and oxygen in the system. [10][11][12] The RAFT process has been applied to a range of monomers, including vinyl, styrene, acrylates, and methacrylates, under relatively mild conditions, to produce a variety of molecular microstructures, including block copolymers, [13] star-shaped molecules, [14] and comb structures. [15] CRP of GMA by ATRP [16,17] and RAFT, [18] as well as copolymerization of GMA with styrene using NMP, [19] are already reported in the literature. Little experimentation has been carried out on RAFT copolymerization of S with GMA, and there are no reports on the synthesis of functional S-GMA copolymers by RAFT polymerization at temperatures higher than 100 °C, which is the range of interest for acrylate-based copolymers.On the other hand, controlling polymer microstructural characteristics, such as copolymer composition, copolymer sequence distribution, and molar mass distribution, is of particular importance in copolymerization processes. The estimation of monomer reactivity ratios in copolymerization studies is essential for determining polymerization rates and copoly mer sequence distributions, which support the manufacture of copolymers with the desired properties. This information is very important for selection of the reaction conditions needed to produce a desired product. On the other hand, the industrial RAFT CopolymerizationThe bulk reversible addition-fragmentation chain transfer (RAFT) copolymerization of glycidyl methacrylate (GMA) and styrene (S) at several GMA molar feed fractions in the presence of 2-cyano isopropyl dodecyl trithiocarbonate as RAFT agent and 1,10-azobis(cyclohexane carbonitrile) as initiator is reported. The reaction conditions are similar to those used in the industrial production of crystal and high-impact ...

Effect of copolymers synthesized by nitroxide‐mediated polymerization as chain extenders of postconsumer poly(ethylene terephthalate) waste

“…As observed in Table , the synthesized poly(GMA‐ran‐S) copolymers exhibited narrow Ð values which ranged from 1.21 in the case of 16% GMA to 1.32 when GMA content is 46%. Ð was slightly higher for the copolymers richer in GMA, indicating that it is more difficult to control the reaction as GMA content is increased, which was expected .…”

Phenylalanine‐Tethered pH‐Responsive Poly(2‐Hydroxyethyl Methacrylate)

“…Among several RAFT agents, trithiocarbonate‐based CTA's gain the major applicability due to their broad scope of vinylic‐monomers [37,38] . The RAFT polymerization of Boc‐Phe‐EMA using 4‐cyano‐4‐(dodecylsulfanylthiocarbonyl)sulfanyl‐pentanoic acid (CDP) as CTA was previously reported by our group, providing homopolymers with low dispersity (Ð) values and controlled molecular weights [22] . Taking the previous observations in mind, in the present study both the homopolymerizations were carried out maintaining the ratios of [monomer] : [CDP] : [2,2’‐azobis‐(2‐methylpropionitrile) (AIBN)]=50 : 1 : 0.2, in DMF solvent at 70 °C (Scheme 1).…”

“…[37,38] The RAFT polymerization of Boc-Phe-EMA using 4-cyano-4-(dodecylsulfanylthiocarbonyl) sulfanyl-pentanoic acid (CDP) as CTA was previously reported by our group, providing homopolymers with low dispersity (Ð) values and controlled molecular weights. [22] Taking the previous observations in mind, in the present study both the homopolymerizations were carried out maintaining the ratios of The molecular weights of homopolymers were determined by SEC using DMF as eluent. For the homopolymerization of Boc-Phe-EMA, narrow and unimodal molecular weight distribu-Scheme 1.…”

“…Over the past few years, controlled radical polymerization (CRP) has gained tremendous attention due to their ability to produce polymeric materials with well-defined molecular weight and micro-structure. [22] Among the main CRP techniques nitroxide-mediated polymerization (NMP), [23] atom transfer radical polymerization (ATRP) [24] and reversible addition-fragmentation chain transfer (RAFT) polymerization, [25,26] RAFT method is considered as most versatile due to the high tolerating nature over a wide range of monomers [27] and initiators as well as experimental conditions like solvent and temperature. [28,29] However, the RAFT polymerization of amino-acid based vinylic monomer composed of free amine functionality is not feasible since the free À NH 2 group can react with the RAFT agent.…”

Improvement of Mechanical Properties of Anisotropic Glassy Polystyrene by Introducing Heat-Labile Reversible Bonds

“…The presence of a chain transfer agent may also have an influence. 27 The figure S3). This is expected since the 4-vinylbenzoic acid is depleted early in the polymerization.…”