Copolymerizations of methyl methacrylate (MMA) and ethyl acrylate (EA), both monofunctional monomers, with ethylene glycol diacrylate (EGDA) as the brancher (a difunctional monomer) have been carried out via free-radical solvent-free suspension polymerization using 2,2′-azobis(isobutyronitrile) (AIBN) as the source of radicals, in the presence of a chain transfer agent (CTA) to avoid cross-linking and produce only branched polymers. Investigation of various CTAs led to the choice of 1-dodecanethiol (DDT) mainly due to its low volatility and hydrophobicity. Typically, EGDA/DDT mole ratios of ≤0.7 ensure that cross-linking is avoided. The molar mass and the branching architecture of the polymers have been characterized by MALS/SEC and the thermal and rheological behavior by DSC and melt rheology, respectively. The results confirm earlier indications from solution and emulsion polymerizations of the versatility of the “Strathclyde methodology” in producing branched polymers, in this instance in the form of free-flowing spherical particulates and have allowed demonstration of the differences in the thermal and rheological behavior of the branched products relative to their linear analogues.

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The physical properties of selected room temperature ionic liquids (RTILs) were measured using differential scanning calorimetry, du Nouy tensiometry, and rheometry primarily to determine their suitability for use in electrochemical double layer capacitors. RTILs have other uses, however, such as liquid-liquid extraction, catalysis, and heat transfer, and these measurements may also be of use to researchers working in other fields. The ionic liquids used were 1-ethyl-3-methylimidazolium dicyanamide [emim][N(CN) 2 ], 1,2-dimethyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide [dmpim][Tf 2 N], and 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate [bmpyr][Pf 3 PF 3 ]. Glass transition temperatures, crystallization and melting temperatures, surface tensions, and viscosities are reported. The three ionic liquids displayed a range of crystallization behaviors when cooled to 123.15 K and reheated to 403.15 K. All liquids were Newtonian over a range of shear rates from (10 to 1000) s -1 . Viscosities decreased with temperature, and this has been modeled using the Williams-Landel-Ferry equation.

The influence of different processing methods on the nature of the dispersion achieved in the creation of a polyurethane nanocomposite is presented. The nanocomposites were produced using two different types of organically modified montmorillonite clays and a sample of fine particles of silicon nitride as a reference material. Rheological data were used to assess the nature of the dispersion achieved using the different processing methods. The nature of the dispersion produced was characterized using wide-angle X-ray scattering measurements of the finally cured products. Dynamic mechanical thermal analysis was used to investigate the effect of the incorporation of clay platelets into the matrix of the polymer. The high-temperature modulus provides evidence of the interaction between the polymer and the clay platelets; however, surprisingly, the glass transition temperatures of the filled and unfilled materials were almost identical

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