Abstract: Disclosed is a method for preparing polylactone by ring opening, belonging to the technical fields of organic catalysis and polymer materials. The invention proposes a new catalytic mechanism, wherein an organic alcohol is used as an initiator to initiate ring opening polymerization of a cyclic monomer under the catalysis of an organic catalyst to obtain a polylactone; and the catalyst is a pyridinium salt. The present invention has the advantages of non-toxic reaction, simple conditions and controllable process; further, the invention can obtain a narrow molecular weight distribution in the absence of solution polymerization, and can effectively inhibit the occurrence of the transesterification compared with the catalysis of 4-(N,N-dimethylamino)pyridine.

Abstract: Disclosed in the present invention is a preparation method for a polyester, relating to the technical field of organic catalysis and polymeric materials. The preparation method in the present invention comprises: (1) using pyridine and saccharin in a ratio of 1:1 to prepare pyridine saccharin salt in tetrahydrofuran at 60° C. and separating the pyridine saccharin salt out in methanol and hexane. (2) Freeing out a small amount of pyridine from the pyridine saccharin salt in a heating state, catalyzing by the pyridine saccharin salt and pyridine a cyclic lactone or a carbonate to be ring-opened and polymerized to form the polyester; and the system has no other compound residues. (3) In the presence of an alcohol initiator, catalyzing by the pyridine saccharin salt the cyclic lactone to be ring-opened and polymerized to obtain the polyester. The catalytic system can efficiently synthesize a specific polylactone.

Abstract: Disclosed in the present invention is a preparation method for a polyester, relating to the technical field of organic catalysis and polymeric materials. The preparation method in the present invention comprises: (1) using pyridine and saccharin in a ratio of 1:1 to prepare pyridine saccharin salt in tetrahydrofuran at 60° C. and separating the pyridine saccharin salt out in methanol and hexane. (2) Freeing out a small amount of pyridine from the pyridine saccharin salt in a heating state, catalyzing by the pyridine saccharin salt and pyridine a cyclic lactone or a carbonate to be ring-opened and polymerized to form the polyester; and the system has no other compound residues. (3) In the presence of an alcohol initiator, catalyzing by the pyridine saccharin salt the cyclic lactone to be ring-opened and polymerized to obtain the polyester. The catalytic system can efficiently synthesize a specific polylactone.

Abstract: Disclosed is a method for preparing polylactone by ring opening, belonging to the technical fields of organic catalysis and polymer materials. The invention proposes a new catalytic mechanism, wherein an organic alcohol is used as an initiator to initiate ring opening polymerization of a cyclic monomer under the catalysis of an organic catalyst to obtain a polylactone; and the catalyst is a pyridinium salt. The present invention has the advantages of non-toxic reaction, simple conditions and controllable process; further, the invention can obtain a narrow molecular weight distribution in the absence of solution polymerization, and can effectively inhibit the occurrence of the transesterification compared with the catalysis of 4-(N,N-dimethylamino)pyridine.