Facile, versatile and cost effective route to branched vinyl polymers

O'Brien, Nathan; McKee, Anthony; Sherrington, David C.; Slark, Andrew T.; Titterton, A

doi:10.1016/s0032-3861(00)00016-1

Cited by 259 publications

(279 citation statements)

References 24 publications

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“…The "active site transfer" mechanism can also be designed to yield soluble products through free radical copolymerizations of monomers and crosslinkers. Sherrington et al investigated the effect of adding large amounts of thiol-based chain transfer agents to avoid gelation to obtain branched methacrylic copolymers [43]. The specific concept of "active site transfer" has also been investigated in the RAFT polymerization of methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA) [44]; anionic SCVP of divinylbenzene (DVB) and 1,3-isopropenylenebenzene [45]; AT-SCVP of DVB and (1-bromoethyl)benzene [46]; AT-SCVP of EGDMA and bisphenol A dimethacrylate [47]; and deactivation-enhanced AT-SCVP of commercially available multifunctional vinyl monomers [48].…”

Section: Introductionmentioning

confidence: 99%

Tuning the Solubility of Copper Complex in Atom Transfer Radical Self-Condensing Vinyl Polymerizations to Control Polymer Topology via One-Pot to the Synthesis of Hyperbranched Core Star Polymers

2014

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Abstract:In this paper, we propose a simple one-pot methodology for proceeding from atom transfer reaction-induced conventional free radical polymerization (AT-FRP) to atom transfer self-condensing vinyl polymerization (AT-SCVP) through manipulation of the catalyst phase homogeneity (i.e., CuBr/2,2'-bipyridine (CuBr/Bpy)) in a mixture of styrene (St), 4-vinyl benzyl chloride (VBC), and ethyl 2-bromoisobutyrate. Tests of the solubilities of CuBr/Bpy and CuBr2/Bpy under various conditions revealed that both temperature and solvent polarity were factors affecting the solubility of these copper complexes. Accordingly, we obtained different polymer topologies when performing AT-SCVP in different single solvents. We investigated two different strategies to control the polymer topology in one-pot: varying temperature and varying solvent polarity. In both cases, different fractions of branching revealed the efficacy of varying the polymer topology. To diversify the functionality of the peripheral space, we performed chain extensions of the resulting hyperbranched poly(St-co-VBC) macroinitiator (name as: hbPSt MI) with either St or tBA (tert-butyl acrylate). The resulting hyperbranched core star polymer had high molecular weights (hbPSt-g-PSt: Mn = 25,000, Đ = 1.77; hbPSt-g-PtBA: Mn = 27,000, Đ = 1.98); hydrolysis of the tert-butyl groups of the later provided a hyperbranched core star polymer featuring hydrophilic poly(acrylic acid) segments. OPEN ACCESSPolymers 2014, 6 2553

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Section: Introductionmentioning

confidence: 99%

Tuning the Solubility of Copper Complex in Atom Transfer Radical Self-Condensing Vinyl Polymerizations to Control Polymer Topology via One-Pot to the Synthesis of Hyperbranched Core Star Polymers

2014

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“…[1] The synthesis of hyperbranched polymers is a well established subject for step-growth polymerization systems but less developed when vinyl monomers are involved. For this reason, in the latest few years, some works concerning the production of hyperbranched materials involving multi-functional vinyl monomers and using classical [1][2][3] or living [4] radical polymerization have been published. A major problem of these polymerization systems is the occurrence of gelation for low monomer conversion even when a small amount of multi-functional vinyl monomer is used.…”

Section: Introductionmentioning

confidence: 99%

“…A major problem of these polymerization systems is the occurrence of gelation for low monomer conversion even when a small amount of multi-functional vinyl monomer is used. In the aforementioned works [1][2][3][4] some strategies have been put forward (such as the introduction of a chain transfer agent) to minimize this problem and make possible the production of soluble branched polymers at high monomer conversion. In another application field, copolymer networks are intentionally prepared by promoting the gelation of mono-and divinyl monomers, specially styrene þ divinylbenzene.…”

Section: Introductionmentioning

confidence: 99%

Time Programmed Feed of Semi‐Batch Reactors with Non‐Linear Radical Copolymerizations: An Experimental Study of the System Styrene + Divinylbenzene Using SEC/MALLS

Gonçalves

Dias

Costa

2007

Macromolecular Symposia

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Summary:The radical crosslinking copolymerization of mono and divinyl monomers was experimentally studied with a 2.5 dm 3 semi-batch reactor using styrene þ divinylbenzene as a model system. The analysis of products was carried out by SEC with a MALLS detector. The influence of the feed policy of divinylbenzene on the time evolution of the copolymer molecular weights and z-average mean square radius of gyration was assessed. A detailed kinetic model, in the absence of intramolecular reactions but taking into account the presence of the two isomers m-and p-in the commercial divinylbenzene and the different reactivities of the various radicals and double bonds was developed; most parameters have been collected from previous kinetic studies, and only two have been regressed using our measured molecular weights. These results can be used to improve the production of branched/crosslinked polymers with controlled molecular architecture.

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“…Hence, in spite of the fact that the synthetic strategies applied deliver poorer control over the molecular structure of these hyperbranched polymers when compared to "true" dendrimers, the economic and practical advantages from adopting these strategies are generally gained without significant negative impact upon the desired beneficial/differentiated material properties. 1,[3][4][5][6][7][8][9][10][11][12] In addition, these more affordable and accessible approaches have led to significant industrial interest targeted towards using these materials in larger scale applications such as imaging agents, reactive resins and industrial coatings. 1,[13][14][15] Compared to linear polymers, highly/hyper branched polymers often exhibit improved solubility, lower (melt) viscosity, higher density of functional-groups and have a more compact/globular structure.…”

Section: Introductionmentioning

confidence: 99%

“…[3][4][9][10][11][12][31][32][33][34][35][36][37][38][39][40] The 'Strathclyde Method' was a pivotal early example of such a branching synthetic strategy and centred on the standard free radical (SFR) copolymerisation of monofunctional and difunctional vinyl monomers. [9][10][11][12] One of the main conclusions drawn from this work was that gelation, i.e. the formation of an extended crosslinked network, occurred when an average of two or more branch points per chain was achieved.…”

Section: Introductionmentioning

confidence: 99%

Facile one-spot synthesis of highly branched polycaprolactone

et al. 2014

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Reported is the first solvent-free (bulk) synthesis of degradable/bioresorbable, highly branched polymers via tin octanoate Sn(Oct 2 ) catalysed controlled ring opening copolymerisation (ROP) of mono and di-functional lactone monomers that proceed to near quantitative conversion. The successful isolation of solvent soluble, highly branched structures was shown to be dependent on both the concentration of the di-functional monomer and the overall reaction time. Comparison with analogous systems utilising controlled radical polymerisation (CRP) to form the highly/hyper branched polymers suggested significant experimental differences between the two chain growth methods. The maximum proportion of di-functional monomer without gelation ensuing was found to be 0.6 equivalents w.r.t. mono-functional monomer (c.f. 1 with CRP) and the onset of significant levels of branching occurred at approximately 90% conversion (c.f. ~70% with CRP). These differences and significant disparity in reaction times were attributed to (a) the coordination and insertion (C+I) propagation mechanism adopted by the Sn catalyst and (b) the presence of additional trans-esterification reactions at high conversion. Evidence is presented to support the conclusion that there are two mechanisms contributing to the overall branching process in the ROP system at high conversion. First, the C+I mechanism promotes growth of linear polymer until approximately 90% conversion, after which both the C+I and transesterification processes contribute to the interchain branching process. The branched nature of the molecular structures was supported by confirmation plots generated from static light scattering. This data demonstrated that the polymers synthesised exhibit varying degrees of branching, consistent with the di-functional monomer (4, concentration in the feed. The degree of branching was calculated using 3 different methods 2 and the results were shown to be independent of method. Finally, DSC analysis of the polymers demonstrated correlation between the degree of branching achieved and the observed T m for the material where increased branching leads to a drop in the recorded T m .

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Facile, versatile and cost effective route to branched vinyl polymers

Cited by 259 publications

References 24 publications

Tuning the Solubility of Copper Complex in Atom Transfer Radical Self-Condensing Vinyl Polymerizations to Control Polymer Topology via One-Pot to the Synthesis of Hyperbranched Core Star Polymers

Tuning the Solubility of Copper Complex in Atom Transfer Radical Self-Condensing Vinyl Polymerizations to Control Polymer Topology via One-Pot to the Synthesis of Hyperbranched Core Star Polymers

Time Programmed Feed of Semi‐Batch Reactors with Non‐Linear Radical Copolymerizations: An Experimental Study of the System Styrene + Divinylbenzene Using SEC/MALLS

Facile one-spot synthesis of highly branched polycaprolactone

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