Functionalised emulsion-templated polymers (PolyHIPEs) are reported as new materials for electroanalytical applications. PolyHIPEs, which are prepared from high internal phase emulsions (HIPEs), were tailored by optimisation of polymerisation conditions to yield well-defined, tubular, porous membranes. The PolyHIPE membrane backbone was activated by incorporating ionophores, graphite particles, electron mediators and enzymes. The results show that a valinomycin ionophore impregnated, plasticised membrane shows a Nernstian response to K + ions with improved detection limits and selectivity coefficients compared to traditional PVC membranes. The graphite/mediator/enzyme loaded membranes exhibit quasi-reversible redox behaviour with semi-infinite linear diffusion at fast scan rates tending to radial diffusion at slow scan rates. Additionally, composite, asymmetric membrane structures with a porous PolyHIPE membrane and a PVC membrane exclude proteins such as BSA (bovine serum albumin) and a 1 acid glycoprotein (AAG). These preliminary results demonstrate that plasticised membranes with functionalised skeletons and with controllable porosity such as PolyHIPE membranes are very promising for the fabrication of sensors with integrated separation.

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With the application of multi-level template, the incidence of cortex perforation in severe and rigid scoliosis decreased and this technology is, therefore, potentially applicable in clinical practice.

Crosslinked ethylene-vinyl acetate (EVA) copolymers with VA content of 28% by weight were prepared by a two-step method by evenly dispersing the crosslinking agent (dicumyl peroxide) into the EVA matrix and then crosslinking at elevated temperatures. The crosslinking features of the samples were analyzed by Soxhlet extraction with xylene and dynamic mechanical measurements. All the samples were crystalline at room temperature, and the chemical crosslinks seemed to have little effect on the melting behavior of polyethylene segment crystals in the EVA copolymers. The shape recovery results indicated that only those specimens that had a sufficiently high crosslinking degree (gel content higher than about 30%) were able to show the typical shape memory effect, a large recoverable strain, and a high final recovery rate. The degree of crosslinking can be influenced by the amount of the peroxide and the time and temperature of the reaction. The response temperature of the recovery effect (about 61°C) was related to the melting point of the samples. The EVA shape memory polymer was characterized by its low recovery speed that resulted from the wide melting range of the polyethylene segment crystals.

A multi-Lorentzian-splitting algorithm is used to distinguish the 1H NMR signal of free PEG from that of grafted PEG, therefore allowing monitoring of the grafting process in situ.

Crosslinked ethylene–vinyl acetate (EVA) copolymers with VA content of 28% by weight were prepared by a two‐step method by evenly dispersing the crosslinking agent (dicumyl peroxide) into the EVA matrix and then crosslinking at elevated temperatures. The crosslinking features of the samples were analyzed by Soxhlet extraction with xylene and dynamic mechanical measurements. All the samples were crystalline at room temperature, and the chemical crosslinks seemed to have little effect on the melting behavior of polyethylene segment crystals in the EVA copolymers. The shape recovery results indicated that only those specimens that had a sufficiently high crosslinking degree (gel content higher than about 30%) were able to show the typical shape memory effect, a large recoverable strain, and a high final recovery rate. The degree of crosslinking can be influenced by the amount of the peroxide and the time and temperature of the reaction. The response temperature of the recovery effect (about 61°C) was related to the melting point of the samples. The EVA shape memory polymer was characterized by its low recovery speed that resulted from the wide melting range of the polyethylene segment crystals. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1063–1070, 1999

Polynorbornenes of different molecular weights were synthesised by addition polymerisation, using a nickel based catalyst. This polymerisation route leads to amorphous polymers that were shown to display unique properties: high glass transition temperature, rigid random coil conformation, and dense packing in the amorphous state. Gas permeation membranes were prepared from these addition type nonsubstituted polynorbornenes. A study of their gas transport properties was performed and compared with both substituted addition polynorbornenes and ring opening metathesis polymerised polynorbornenes. The observed behaviour, in terms of permeability and selectivity, is in accordance with the low free volume and the dense packing confirmed by positron annihilation spectroscopy and WAXD in these polymer structures. ᭧

The structure and properties of a polypropylene microporous film prepared by biaxial stretching of non‐porous polypropylene film of high β‐crystal content were investigated. The porosity of these films can be as high as 30–40%, and the average pore size was around 0.05 μm. The films were found to have the structure of a two‐phase interpenetrating network; both the polypropylene and the pore regions were three‐dimensionally continuous. The advantages of the biaxially stretched microporous films are the combination of high permeability to fluids with good mechanical properties and almost circular pore shape with narrow pore size distribution. The application of this microporous film for battery separators, filtration membranes and substrates of functional polymer composites is discussed.