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| PATENT EXAMPLES |
To prepare the CPP polymer 40 grams of CPP powder was added to 500 ml boiled acidic anhydride at approximately 130 degrees C. under dry nitrogen reflux. The reaction was stopped after 15 min. and the solution was filtered through a filter paper to another 1 liter round bottom flask. The solution was then concentrated to 150 ml by evaporation. The solution was allowed to crystallize which was then separated by filtration and transferred to 200 ml of anhydrous diethyl ether in an erlenmeyer flask and allowed to swirl for several hours at room temperature. The white crystals were separated by filtration and dried in a calcium chloride desicator under vacuum. It is essential that the degree of polymerization of the prepolymer not be greater than 4 by G.C.P. A sebacic acid prepolymer was prepared by refluxing 60 grams of sebacic acid with 250 ml of acidic anhydride under nitrogen for 90 minutes. The excess acetic anhydride was evaporated from the prepolymer which was then recrystallized from toluene. The crystals were then filtered and recrystallized in a mixture of petroleum ether and anhydrous diethyl ether. The white crystals were then separated by filtration and dried under vacuum. EXAMPLE II A 50:50 CPP:SA copolymer was prepared by mixing 2.0 grams of the CPP prepolymer with 1.15 grams of the sebacic acid prepolymer as prepared in Example I. The polymerization was carried out at 180 degrees C. under high vacuum (less than 10.sup.-2 mm Hg) for 90 minutes using the same procedure as in Example I. The resulting CPP:SA (50:50 ) copolymer had a weight average molecular weight of 38,200. |
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