Method for preparing poly-oxalate-1,4-butylene

The invention relates to a method for preparing poly-oxalate-1,4-butylene, and belongs to the technical field of high polymer materials. The method comprises the following steps of: putting diethyl oxalate, 1,4-butanediol and a catalyst into a reactor, and reacting at the constant temperature of between 80 and 170 DEG C with stirring under the protection of N2 with the flow of between 0.06 and 0.16 m /hour for 0.5 to 5 hours to obtain the poly-oxalate-1,4-butylene, wherein a ratio of the diethyl oxalate to the 1,4-butanediol is 1:1-1:3; and the catalyst is oxalic acid preferably, and the catalyst is 0.1 to 5.0 molar percent based on the diethyl oxalate. In the method, the diethyl oxalate and the 1,4-butanediol also can react at the constant temperature of between 110 and 180 DEG C under the vacuum degree of between 200 and 500 Pa under constant pressure for 3 to 8 hours in the presence of the catalyst to obtain the poly-oxalate-1,4-butylene with higher intrinsic viscosity. By the method, the reaction time is shortened, the vacuum degree of the reaction is reduced, the cost is low, and operation and aftertreatment are simple, so the method is suitable for industrial production.