means in the reaction tube employed in the process of this invention the length of the reaction tube is several orders of magnitude greater i e at least about 10 3 times greater than the diameter or major cross sectional dimension of the tube for example the length of the tube will generally be about 100 m to about 600 m preferably about 323 2 m the cross sectional area of the reaction tube will usually be about 707 mm 2 to about 7854 mm 2 preferably about 2043 mm 2 thus it can be seen that the length of the reaction tube is much larger than the major cross sectional dimension the flow characteristics of the reactants through the reaction tube can be either turbulent or laminar flow the flow rate of reactants under pressure through the reaction tube is about 1 5 to about 10 m 3 hr preferably about 3 m 3 hr the reaction tube can be provided with external cooling means in order to maintain isothermal reaction conditions in the case of a jacketed reaction tube the heat of reaction can be removed by water or oil circulating through the jacket it is another essential feature of the present invention that the reaction time in the reaction tube be between 3 84 min and 35 89 min even with such relatively short reaction times it is possible to attain yields of about 96 to about 100 related to weight of resinifiable material upon the substantial completion of the polymerization reaction in the.