using a heating mantle to 60 u00b0 c then 347 4 g of molten 50 u00b0 c isonate 2125m 4 4 39 diphenylmethane diisocyanate dow chemical co midland michigan were added and the contents of the reactor were mixed without heating for six minutes after which the temperature was 59 u00b0 c next 11 drops 0 31 g of dabco t 9 stannous type organometallic catalyst air products and chemicals inc allentown pa were added two minutes later an exotherm to 90 u00b0 c was observed after three additional minutes at t 86 u00b0 c 750 0 g of px 316 mixed n alkylphthalate aristech were added gradually over a four minute period after which the temperature had dropped to 69 u00b0 c a vacuum was gradually applied over a 23 minute period full vacuum greater than 29 in hg was then maintained for 10 minutes the resulting plasticized urethane prepolymer was then discharged into airtight high density polyethylene jars of 32 fluid ounce capacity for storage and later use ______________________________________test results ______________________________________ nco 1 27brookfield viscosity cp 33 000 model rv spindle 6 20 rpm 23 u00b0 c ______________________________________ into a two gallon ross double planetary mixer 393 8 g of plasticized prepolymer from example 3 were.