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A new metallocene-based polymerization mechanism is elucidated in which a zirconium hydride center inserts α-methylstyrene at the start of a polymer chain. The hydride is then regenerated by hydrogenation to release a polyolefin containing a single terminal α-methylstyrenyl group. Through the use of the difunctional monomer 1,3-diisopropenylbenzene, this catalytic hydride insertion polymerization is applied to the production of linear polyethylene and ethylene-hexene copolymers containing an isopropenylbenzene end group. Conducting simple radical polymerizations in the presence of this new type of macromonomer leads to diblock copolymers containing a polyolefin attached to an acrylate, methacrylate, vinyl ester, or styrenic segments. The new materials are readily available and exhibit interfacial phenomena, including the mediation of the mixing of immiscible polymer blends.

Amphiphilic block copolymers comprised of polyisobutylene (PIB) and poly(2-(dimethylamino)ethyl methacrylate) (DMAEMA) have been synthesised. This has been achieved via two new synthetic processes. Firstly, a PIB macroinitiator was synthesised from PIB that is primarily terminated by an α-olefin, hydroboration/oxidation of the terminal α-olefin followed by esterification with α-bromoisobutyryl bromide furnished the desired macroinitiator. The PIB macroinitiator was then utilised to polymerise DMAEMA by SET-LRP at different block lengths of PDMAEMA. However, end fidelity of the PIB macroinitiator was low (60%) and as such synthesising a block of PDMAEMA with a predictable degree of polymerisation was not possible. PIB-b-PDMAEMA block copolymers were also synthesised by reactive coupling of functional homopolymers, primary amine terminated PDMAEMA and polyisobutenyl succinic anhydride (PIBSA). Variable molecular weight well-defined PDMAEMA was synthesised by SET-LRP using an azide bearing initiator followed by transformation of the azide end group to a primary amine. All primary amine functionalised PDMAEMA was then coupled with PIBSA to synthesise PIB-b-PDMAEMA, demonstrated by GPC. However, the capabilities of this synthetic approach was limited as more than one PDMAEMA may couple to the PIBSA, therefore not synthesising pure PIB-b-PDMAEMA copolymers.

The synthesis of a monoacrylate functionalized poly(isobutylene) (PIB) macromonomer (PIBA) has been achieved by a two-step reaction starting from a commercially available PIB. Firstly, terminal olefins (vinylidene and trisubsti- tuted olefin) of PIB were transformed to a phenolic residue by Friedel-Crafts alkylation followed by subsequent esterification of the phenol with acryloyl chloride, catalyzed by triethylamine. PIBA structure was confirmed by 1 H-NMR, 13 C-NMR and GPC before utilizing in the RAFT copolymerization with N,N-dime- thylacrylamide (DMA) to obtain statistical copolymers (P((DMA- co-(PIBA))). Monomer conversions were consistently higher than 85% for both DMA and PIBA as monomer feed composi- tion was varied. Chain extension of poly(N,N-dimethylacryla- mide) with PIBA to synthesize block copolymers (P((DMA-b- (PIBA))) was also achieved with near quantitative monomer conversions (>97%). Block formation efficiency was not quanti- tative but purification of block copolymers was possible by selective precipitation. V C 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 00, 000-000

Alkyl and tertiary amine functionalized α-methyl styrene (AMS) monomers have been synthesized via reactive coupling of 3-isopropenyl-α,α-dimethylbenzyl isocyanate (TMI) with primary amines. Primary amines utilized include hexylamine, octadecylamine and N,N-dimethylethylenediamine to synthesize monomers, 3-hexyl-1-[1-(m-isopropenylphenyl)-1-methylethyl]urea (AMSC6), 3-octadecyl-1-[1-(m-isopropenylphenyl)-1-methylethyl]urea (AMSC18) and 3-(2-(dimethylamino)ethyl)-1-[1-(m-isopropenylphenyl)-1-methylethyl]urea (AMSDMA), respectively. The structures of these functionalized AMS monomers have been confirmed by 1H-NMR, 13C-NMR and FT-IR. AMS, AMSC6 or AMSC18 was then successfully copolymerized with maleic anhydride (MalA) via free radical polymerization initiated by azobisisobutyronitrile to synthesize alternating copolymers. Free radical homopolymerizations of AMS, AMSC6, AMSC18 and MalA were performed to reveal no monomer conversion by gas chromatography and no formation of polymer chains by gel permeation chromatography (GPC). Alternating copolymers were characterized by GPC, 1H-NMR, FT-IR and MALDI-TOF MS. Finally, post-polymerization modification of P[(AMSC18)-a-(MalA)] by imidization of the MalA repeat unit with a primary amine was performed. This leads to the synthesis of alternating dual functionalized copolymers in an efficient and simple way.

The metal catalyzed polymerization of methyl methacrylate using Cu(0) as the catalyst source has been investigated in toluene. This work looks at polymerizations in a non-polar medium allowing control over the molecular weight and polydispersity with a 4-fold reduction in catalyst concentration versus conventional ATRP, while the use of an active ligand allows the reaction to proceed at room temperature. The use of an excess of PMDETA ligand allows for high conversions, and the addition of a small amount of CuBr 2 enhances living characteristics, enabling efficient chain extension.

The use of copper(I) halides in conjunction with pyridine imine ligands is reported to lead to a range of controlled molecular weight and architecture polymers. The use of multifunctional initiators leads to di-, tri- and tetra-functional star polymers based on pentaerythritol cores. The polymerisations all follow excellent first order kinetics with Mn increasing linearly with conversion. The polymerisation is first order in copper halide. A range of α-functional polymers with 4-[(4-chloro-6-methoxy-1,3,5-triazin-2-yl)amino]phenyl 2-bromo-2-methylpropionate, N-hydroxysuccinimide and phthalimide have been prepared which introduce terminal functionality into polymers for subsequent coupling and potential synthesis of conjugates for biologically active compounds. Finally block/graft amphiphilic copolymers are demonstrated via the preparation of a statistical copolymer macroinitiator containing a hydroxy functionality which is used for the polymerisation of dimethylaminoethyl methacrylate prior to esterification of the hydroxy functionality to give living radical polymerisation initiators which are used subsequently in the polymerisation of methyl methacrylate. Copper(I) mediated living radical polymerisation is shown to be an effective method for the synthesis of a range of functional synthetic polymers.

The chain-transfer constants of methyl (2-bromomethyl)acrylate (MBrMA) in bulk polymerizations of methyl methacrylate (MMA) and styrene were determined at 70 °C using both the Mayo method (1/DPn as well as 2/DPw) and the chain-length-distribution procedure (Λ). The CMBrMA values using 2/DPw and Λ were consistent, i.e., 1.28 and 1.20 for MMA and 11.44 and 10.92 for styrene, respectively. MBrMA was used as a chain-transfer agent in the emulsion polymerization of MMA to yield an α-bromo-functionalized macromonomeric latex (〈Mn〉 = 9.6 × 103 g mol-1; PDI = 1.80), which was subsequently copolymerized with styrene to yield the corresponding poly(styrene-graft-MMA) copolymer. MBrMA was used as an addition−fragmentation agent in the living radical polymerization of MMA mediated by copper(I) bromide/N-(n-octyl)-2-pyridylmethanimine. In situ addition of a 5-fold equivalent of MBrMA and Cu(0) to this polymerization quenched the reaction and transformed the ω-bromide into the methacrylate-based macromonomer quantitati...

The use of copper(I) Schiff base complex catalysed atom transfer polymerisation of methacrylates is described. The use of a range of functional and multi-functional initiators enables the synthesis of a range of functional and star polymers to be prepared under undemanding synthetic conditions. End capping with silyl enol ethers allows for ω-functional polymers. The combination of novel initiators, functional monomers and end capping allows an unprecedented array of macromolecular structures to be produced with limited need for protecting group chemistry.

A range of phenolic esters derived form the esterification of substituted phenols with 2-bromoisobutyryl bromide and 2-chloroisobutyryl chloride have been demonstrated to be effective atom transfer polymerization initiators in conjunction with N-(n-octyl)-2-pyridylmethanimine and copper(I) chloride and bromide. All initiators have been fully characterized. Methoxy, phenyl ether, primary aryl amino, aldehyde, nitro, and benzyl ether functional initiators lead to efficacious atom transfer polymerization without imparting any detrimental effects on the polymerization. Polymerizations have been shown to proceed with excellent first-order kinetics with small amount of termination, as seen by narrow polydispersity indices, often below 1.10. Rates of polymerization are of the of the order of 1 × 10-4 s-1, which gives PMMA of approximately 10 000 g mol-1 after 4 h under typical polymerization conditions. Mn increases linearly with conversion. Polymerization of a range of alkyl methacrylates is demonstrated includ...

Reactivity ratios have been determined for the monomer pair methyl methacrylate and n-butyl methacrylate under a range of polymerization conditions. The value of using reactivity ratios as a mechanistic probe is discussed. Reactivity ratios determined where M1 = MMA and M2 = n-BMA are 1.04, 0.81, classical anionic; 1.10, 0.72 , alkyllithium/trialkylaluminum initiated; 1.76, 0.67, group transfer polymerization; 0.98, 1.26, atom transfer radical polymerization; 0.75, 0.98, catalytic chain transfer; and 0.93, 1.22, classical free radical polymerization. The data suggest ATRP and CCTP proceed via radical type propagation. Li/Al-initiated polymerization undergoes an anionic mechanism, while strong evidence is found for an associative, catalyst dependent mechanism for GTP. Galvinoxyl is demonstrated to inhibit GTP as well as free radical polymerization, and it is suggested that neither the use of inhibition nor polymer stereochemistry can be used to distinguish between anionic and radical processes.

Electrospray preparation of sample slides for matrix-assisted laser desorption/ionization has proved to minimize both sample spot-to-spot and shot-to-shot variations compared to traditional deposition by spotting. © 1997 John Wiley & Sons, Ltd.

Polymerization of styrene in the presence of [Ti(η5-C5H4tBu)Cl3]-methylaluminoxane has been investigated. The resultant polymer is essentially 100% syndiotactic polystyrene (SPS; by NMR and differe...

The metal catalyzed polymerization of methyl methacrylate using Cu(0) as the catalyst source has been investigated in toluene. This work looks at polymerizations in a non-polar medium allowing control over the molecular weight and polydispersity with a 4-fold reduction in catalyst concentration versus conventional ATRP, while the use of an active ligand allows the reaction to proceed at room temperature. The use of an excess of PMDETA ligand allows for high conversions, and the addition of a small amount of CuBr(2) enhances living characteristics, enabling efficient chain extension.

Atom transfer radical polymerisation (ATRP) of methyl methacrylate with a pyridinecarbaldehyde imine copper(I) catalyst and hydroxy functional alkyl bromide initiator leads to α-hydroxy functional PMMA with controlled M n and PDI < 1.20 without the use of protecting group chemistry.

A simple, low-cost, air-spray technique has been evaluated for the preparation of matrix-assisted laser desorption/ionisation (MALDI) sample slides. Hydroxyl end groups of poly(ethylene glycol) Mn = 600 were functionalised by esterification using acetyl and butyryl chlorides. Air-spray deposition gave excellent shot-to-shot and spot-to-spot reproducibility; the observed compositions by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) being in agreement with those obtained from 1 H NMR. Compressed air-spray is an excellent, inexpensive, sample preparation procedure for simple routine MALDI-TOF MS which increases the reproducibility of this increasingly important technique for synthetic polymer analysis.