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Polyamide 6, polyamide 12, polybutyleneterephthalate, and polyetherimide films are plasma treated in an APGD unit using various applied voltages, gas flow rates, frequencies, and dwell times. The results show changes in the surface chemistry (FTIR); the degree of change in dynamic contact angle is found to be dependent on the polymer type, dwell time, and electrical characteristics of the plasma. [ABSTRACT FROM AUTHOR]

The effect of molecular weight on the migratory characteristics of polyisobutylene (PIB) additive from the bulk to the surface of a range of monolayer and multilayer extruded polyethylene films has been analyzed by FTIR-ATR and peel cling analysis. Migration rates are shown to be higher for lower molecular weight PIB additive, and cling strength increases as the PIB molecular weight increases. [ABSTRACT FROM AUTHOR]

A range of EVA-mLLDPE-EVA coextruded films, with polyisobutylene (PIB) masterbatch content of 0-20% and vinyl acetate (VA) comonomer content of 6, 12, and 18%, is manufactured. The films are aged at 45°C for up to 28 days to enable tack (cling) development. The results show that film tack strength improves significantly with aging. Increased VA concentration in the surface layer also shows significant improvement in film tack strength. The film tensile strength, elongation, and tear properties in both machine direction (MD) and transverse direction (TD) are not significantly affected by increase in PIB concentration. Increased VA content shows slight improvement in MD mechanical performance of the films, although TD properties are relatively unaffected. [ABSTRACT FROM AUTHOR]

Polyethylene films, prepared from a range of mLLDPE, LLDPE, and ULDPE resins containing 4% polyisobutylene (PIB) from a masterbatch, are manufactured using a Killion cast film extrusion system. FTIR, DSC, and mechanical analysis techniques are used to investigate the effect of comonomer type, density, and melt flow index (MFI) on the mechanical performance, orientation, and crystallinity of these films. The study established that comonomer type and MFI are the greatest factors influencing the mechanical performance of crystallinity. Crystallinity has been found to be the most influential factor governing PIB migration in these films and this in turn is related to polymer type, density, and MFI. [ABSTRACT FROM AUTHOR]

Bitumen, a mixture of aromatics, paraffins, asphaltenes and resins that remain after crude oil has been fractionally distilled, finds applications in blends with a proportion of a polymer, in built up membranes for the roofing industry. Blends of three commercially used polymers with a 100 penetration grade Nynas bitumen at levels between 9% and 29% w/w were prepared using a Z-blade mixer. The morphology, thermal and dynamic mechanical properties of these blends were examined using fluorescence optical microscopy, differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The blends prepared with these polymers displayed low temperature flexibility and an onset of flow at high temperatures. The former characteristic is required for use in cold environments the latter feature being a critical property when the membrane is manufactured and later when applied by the torching process on a roof. It may be seen how the different blends function in a manner that makes them suitable for the production of built-up roofing membranes. [ABSTRACT FROM PUBLISHER]

As Metallocene Catalysed Polyethylenes (mPEs) become more commercially available they are finding ever increasing application in the blown film industry. However, it is becoming apparent that no two mPE resins behave in exactly the same manner. This paper examines the Theological properties of a range of mPEs with different densities and MFIs. These resins were then blended with a conventional low density polyethylene (LDPE) and extruded to form monolayer films. The mechanical properties of these films were compared to three layer coextruded films of A:B:A structure, where A is LDPE and B is mPE. [ABSTRACT FROM PUBLISHER]