were mixed in a speedmixer from apm technika ag ch 9435 heerbrugg sales marketing d identification plate type dac 150 fvz for 3 minutes at 3000 rpm to form a homogeneous paste 0 005 g of dibutyltin dilaurate metacure u00ae t 12 air products and chemicals inc and 6 06 g of the isocyanate n3300 product from bayermaterialscience ag are then weighed out into the paste and mixed for 1 minute at 3000 rpm in the speedmixer the reaction paste is poured onto a glass plate and spread with a doctor knife in a wet layer thickness of 500 u03bcm to form a homogeneous film with a solids content of 2 the film is then heated for 16 hours at 80 u00b0 c the properties of the heat treated film are given in the following table 1 all liquid raw materials were carefully degassed in a three stage process under argon and the carbon black was screened through a 125 u03bcm screen 10 g of arcol ppg 2000 product from bms ag dmc catalysed polypropylene oxide of mean molecular weight mn 2000 are weighed out together with 0 636 g of carbon black ketjenblack ec 300 type in a 60 ml disposable mixing vessel and are mixed for three minutes at 3000 rpm in a speedmixer 0 005 g of dibutyltin dilaurate and 7 13 g of the isocyanate desmodur.