Statistische copolymeren, blok copolymeren en polymeer composieten bieden meer mogelijkheden dan homopolymeren voor het toepas-sen van biodegradeerbare synthetische polymeren in de genees- kunde

KULeuven Campusbibliotheek Exacte Wetenschappen / UCL - Université Catholique de LouvainSIGLEBEBelgiu

Etheen/alpha-olefine copolymeren: ketenmicrostructuur, morfologie, kristallisatie- en smeltgedrag

SIGLEKULeuven Campusbibliotheek Exacte Wetenschappen / UCL - Université Catholique de LouvainBEBelgiu

ANTISTATIC POLYMER LAYERS BASED ON POLY(ISOTHIANAPHTHENE) APPLIED FROM AQUEOUS COMPOSITIONS

Electrostatic charging of photographic materials can be avoided by applying an antistatic coating to one or both sides of the photographic film. Electronically conducting polymers can be used for this application especially because the conductivity is independent from the relative humidity. However, these polymers usually are deeply coloured. It has been suggested that the absorption of polyisothianaphthene in the visible part of the spectrum is low, due to its low energy band gap. Application of polyisothianaphthene, however, is difficult due to its insolubility. A method is provided wherein an antistatic layer of polyisothanaphthene is coated from an aqueous dispersion. In this method polyisothianaphthene is polymerised in concentrated sulphuric acid and dispersed in water with the help of lambda carrageenan as a polymeric surfactant. Coating from this dispersion on a polyethylene terephthalate substrate yields a transparent antistatic film whose logarithm of the surface resistivity is 8.48 OMEGA/Square

ANTISTATIC POLYMER LAYERS BASED ON POLY(ISOTHIANAPHTHENE) APPLIED FROM AQUEOUS COMPOSITIONS

Electrostatic charging of photographic materials can be avoided by applying an antistatic coating to one or both sides of the photographic film. Electronically conducting polymers can be used for this application especially because the conductivity is independent from the relative humidity. However, these polymers usually are deeply coloured. It has been suggested that the absorption of polyisothianaphthene in the visible part of the spectrum is low, due to its low energy band gap. Application of polyisothianaphthene, however, is difficult due to its insolubility. A method is provided wherein an antistatic layer of polyisothanaphthene is coated from an aqueous dispersion. In this method polyisothianaphthene is polymerised in concentrated sulphuric acid and dispersed in water with the help of lambda carrageenan as a polymeric surfactant. Coating from this dispersion on a polyethylene terephthalate substrate yields a transparent antistatic film whose logarithm of the surface resistivity is 8.48 OMEGA/Square

The use of crosslinking promoters in the gamma-radiolysis of poly(tetrafluoroethylene-co-perfluoromethylvinyl ether). I

Incorporation of 1 wt % of triallyl isocyanurate (TAIC) significantly enhanced the radiation crosslinking of the perfluoroelastomer, poly(tetrafluoroethylene-co-perfluoromethylvinyl ether) (TFE/PMVE). The dose for gelation was lowered by 70% with the presence of TAIC. The additive also improved the tensile properties of TFE/ PMVE both before and after crosslinking by irradiation. Higher radical yields were obtained with the presence of TAIC at 77 K, indicating the crosslinking promoter was acting as a radical trap. ESR studies showed that radiolysis of TAIC and subsequent photobleaching cleaved an allyl branch from the ring structure. Upon thermal annealing, an allyl radical on the TAIC molecule was observed. (C) 1999 John Wiley & Sons, Inc