The resole crosslinking chemistry of thermoplastic vulcanisates(TPVs) was investigated, together with the production of TPVs on extruders. Low molec.wt. olefins were used in combination with EPDM crosslinking experiments to investigate the resole crosslinking chemistry. The fact that enhanced substitution of the olefin/EPDM unsaturation enhanced the reactivity towards the resole strongly supported the cationic character of SnCl2-activated resole crosslinking. Samples were collected along the extruder during TPV preparation to study the physico-chemical phenomena during compounding. It was observed that crosslinking of the EPDM phase took place even when the PE phase was not yet fully molten. Upon complete melting of the PE phase, the blend very rapidly reached its final morphology. A transition from continuous via co-continuous to fully dispersed EPDM, which was driven by crosslinking, was only observed for the 50:50 w/w blend. 13 refs.

Blends of high-impact PS(HIPS) and SBS thermoplastic elastomers (Kraton D1101) were studied in relation to recycling. Binary HIPS/SBS elastomer systems containing up to 85% of SBS elastomer were investigated and the blends were characterised by measuring dynamic mechanical properties, creep and recovery and by defining the morphology. An increase in the SBS content in the blend resulted in disappearance of the PS-related brittle type of fracture, while SBS-related ductile fracture appeared. The best mechanical properties were obtained for HIPS/SBS 90/10 blends. Topographic images of polymer blend fracture surfaces were processed using fractal analysis software to obtain the fractal indices of the surfaces. The average fractal index was less than two for the fracture surfaces of the HIPS/SBS blends. The processing and mechanical properties were shown to be in good agreement with the fractal properties of the fracture surfaces even for heterogeneous polymer blend materials. 34 refs.

Husky Injection Molding Systems' Quadloc Tandem Index System injection moulding machine for large two-component automobile components is described. The QTI system combines tandem technology and the indexing system on a two-platen machine. The use of the machine by Lear Corp. for production of large multi-material automobile components for interior and exterior applications at its original equipment manufacture customers is described with particular attention to a door component made from talc-filled PP and a thermoplastic elastomer. 2 refs.

The production by Gentner GmbH of safety-critical injection mouldings for the automotive industry, particularly in the airbag region, is discussed. The high demands on appearance, haptics and safety in such applications are considered. The moulding machines used, which are from Ferromatik Milacron, are described and the gas-assisted injection moulding of a side-airbag component is outlined. Plastics materials mentioned include glass fibre-reinforced polyamides and thermoplastic ethylene-ester elastomers.

The distribution of processing oil (a paraffinic oil) in PP/dynamically vulcanised EPDM and PP/SEBS blends was studied using dynamic mechanical analysis (DMA), DSC and dielectric relaxation spectroscopy. In both types of blend, the paraffinic oil was present in both the PP and in the elastomer phase. DMA and DSC results showed the plasticising effects on the glass transitions in the PP and the elastomer phase but there was no unambiguous way to determine the phase-specific oil concentration from the glass transition temperature depressions because of the overlap in the glass transition regions. Using dielectric spectroscopy, with dielectric probes, it was possible to analyse and separate the glass transition processes of the two individual oil-containing phases. The mean value for the oil distribution coefficient was 0.6 for PP/SEBS blends and 0.63 for PP/EPDM blends. 21 refs.

A look is taken at the market for medical plastics, recent developments in polymers and packaging films for the medical industry and some award-winning designs of medical devices. Some of the polymers and devices mentioned include PEEK for implants and coatings, medical-grade PU elastomers, thermoplastic elastomers, thermoformed PU medical balloons, antibacterial polymers, engineering plastics, a portable, automated blood collection system and an electrocardiogram monitoring system. A list of contacts is included

An investigation was carried out into the effect of morphology on the storage modulus and compression set of segmented block copolymers consisting of alternating mobile polyether segments with a low Tg and rigid segments with a high Tg and/or high melting temperature. Systems, which only crystallise, were compared with systems, which only phase separate by liquid-liquid demixing and the effects of segment length and concentration on the properties of these systems evaluated. 13 refs.

The degree of mixing of composites of plasticised poly(styrene-b- (ethylene-co-butylene)-b-styrene) triblock copolymer thermoplastic elastomer with different grades of graphite powder, subjected to processing by batch mixing, co-rotating and counter-rotating twin screw extruders, was investigated using WAXD and TGA. The results are discussed in terms of the correlation between mixing index and the electrical properties of the conductive composites. 35 refs.

General Motors is driving the use of exterior auto plastics using a film in place of a standard paint line, with parts launching on five vehicles, ranging from bumper fascia to rocker panels. GM has opted for a thick thermoformed sheet and intends to develop a supply base that can support even more production. GM first used a thermoformed sheet combining a TPO base with a body-colour film replacing paint on a stone shield on its SSR sports roadster truck. The thick-sheet thermoforming reduces the number of manufacturing steps, shortening development time while also cutting costs. The GM system takes advantage of films produced by Soliant that can match the full line of automotive paint colours.