[Problem to be Solved] To Provide a method for producing an acid-decomposable polymer having a reduced metal ion content, which suppresses decomposition and deprotection of the acid-decomposable polymer.

[Means to Solve the Problem] The method for producing an acid-decomposable polymer according to the present invention comprises the steps of: preparing a polymer solution comprising an acid-decomposable polymer; washing an acidic cation exchanger with an organic solvent until the water content in the organic solvent discharged from the acidic cation exchanger falls to 400 ppm or less; and passing the polymer solution through the washed acidic cation exchanger to reduce the metal ion content of the polymer.

[Problem to be Solved] To Provide a method for producing an acid-decomposable polymer having a reduced metal ion content, which suppresses decomposition and deprotection of the acid-decomposable polymer.

[Means to Solve the Problem] The method for producing an acid-decomposable polymer according to the present invention comprises the steps of: preparing a polymer solution comprising an acid-decomposable polymer; washing an acidic cation exchanger with an organic solvent until the water content in the organic solvent discharged from the acidic cation exchanger falls to 400 ppm or less; and passing the polymer solution through the washed acidic cation exchanger to reduce the metal ion content of the polymer.

This invention relates to the synthesis of multi-block bioresorbable polymers bearing hard and soft polymeric segments. The invention further relates to bioresorbable polymers for shape memory properties. The invention also relates to the use of such polymers as bone filler, vascular closure devices, hemostasis device, aneurysms, mastectomy devices and stent applications. The invention relates also to the use of such polymers for applications in fast degradation applications and 3D printing. The invention also relates to the use of such polymers as drug delivery platforms applications.

This invention relates to the synthesis of multi-block bioresorbable polymers bearing hard and soft polymeric segments. The invention further relates to bioresorbable polymers for shape memory properties. The invention also relates to the use of such polymers as bone filler, vascular closure devices, hemostasis device, aneurysms, mastectomy devices and stent applications. The invention relates also to the use of such polymers for applications in fast degradation applications and 3D printing. The invention also relates to the use of such polymers as drug delivery platforms applications.

A piezoelectric polylactic acid material is has a layered stacking structure, and a porous structure is formed between stacked layers. The piezoelectric polylactic acid material has a piezoelectric constant of 5.2-35.3 pC/N, has the ability to efficiently catalyze dye/pigment degradation, and can be used in the fields of dye/pigment degradation and tooth whitening. A preparation method for the piezoelectric polylactic acid composite material is also provided.

A piezoelectric polylactic acid material is has a layered stacking structure, and a porous structure is formed between stacked layers. The piezoelectric polylactic acid material has a piezoelectric constant of 5.2-35.3 pC/N, has the ability to efficiently catalyze dye/pigment degradation, and can be used in the fields of dye/pigment degradation and tooth whitening. A preparation method for the piezoelectric polylactic acid composite material is also provided.

The present invention is directed to devices and methods for monitoring the purity of monomers, adjusting the polymerization conditions, and consequently improving a polymerization reaction process. In one method, monomer purity is estimated using an on-line evaluation by raising the temperature of the monomer formulation having a defined melting point to a first elevated temperature at least 20 C. above a preset melting point for a selected monomer formulation; cooling the monomer formulation at a controlled cooling rate in the range from about 0.5 to 50 C. per minute; measuring at least one critical property selected from the group consisting of a) crystallization peak temperature at the onset of crystallization, b) an area under the crystallization peak, which represents the heat or enthalpy of crystallization, Hc and combinations thereof, comparing the at least one of the selected critical properties measures relative to such properties for standard setting monomer formulations.

The invention relates to a continuous process for producing an aliphatic polyester constructed from aliphatic dicarboxylic acids and aliphatic diols comprising the steps of a) esterification, b) polycondensation and optionally c) chain extension, characterized in that during step b) in which the polycondenser functions as a degassing apparatus (B) and/or b) after the polycondensation in an additional degassing apparatus (B) the crude polyester is degassed at a pressure of 0.01 to 5 mbar in the presence of 1% to 7% by weight, based on the total weight of the crude polyester of water, introduced into the gas space of the degassing apparatus B and/or B as an entraining agent.

The invention relates to a continuous process for producing an aliphatic polyester constructed from aliphatic dicarboxylic acids and aliphatic diols comprising the steps of a) esterification, b) polycondensation and optionally c) chain extension, characterized in that during step b) in which the polycondenser functions as a degassing apparatus (B) and/or b) after the polycondensation in an additional degassing apparatus (B) the crude polyester is degassed at a pressure of 0.01 to 5 mbar in the presence of 1% to 7% by weight, based on the total weight of the crude polyester of water, introduced into the gas space of the degassing apparatus B and/or B as an entraining agent.

The present invention relates to a continuous process for purifying a chain-extended aliphatic polyester constructed from aliphatic dicarboxylic acids and aliphatic diols in a degassing apparatus, wherein the crude polyester is degassed for 3 to 30 minutes at a pressure of 0.01 to 5 mbar in the presence of 1% to 7% by weight, based on the total weight of the crude polyester, of an entraining agent.