PROCESS FOR PRODUCING VARIOUS MOLECULAR WEIGHT POLYESTERS

    公开(公告)号:US20250066546A1

    公开(公告)日:2025-02-27

    申请号:US18724373

    申请日:2022-12-20

    Abstract: In an aspect, a method for reducing the molecular weight of a polyester, comprises mixing a composition comprising a polyester oligomer and a polyester in a molten state to form a modified polyester; wherein the mixing occurs at a temperature of 230 to 330° C.; wherein the polyester oligomer is present in an amount of 0.1 to 50 weight percent based on 5 the total weight of the composition; wherein the polyester comprises a C2-12 alkyl phthalate polyester having a weight average molecular weight, Mwi, of 15,000 to 100,000 g/mol determined using gel permeation chromatography based on polystyrene standards; and wherein the modified polyester has a weight average molecular weight, Mwf, of at least 5% less than the weight average molecular weight of the polyester.

    Process for the production of thermoplastic polyester

    公开(公告)号:US20190338071A1

    公开(公告)日:2019-11-07

    申请号:US16474616

    申请日:2017-12-06

    Abstract: The present invention relates to a process for the production of a thermoplastic polyester using a reaction mixture comprising a dicarboxylic acid having a melting temperature of ≥200° C. wherein the dicarboxylic acid is introduced to the process in the form of particles having an average particle diameter of ≥100 μm. Such process results in a reduction of the polymerisation time. Furthermore, it allows for the production of thermoplastic polyesters having a desired balance of intrinsic viscosity and carboxylic end group content at a reduced polymerisation time.

    METHOD FOR PRODUCING VARIOUS MOLECULAR WEIGHT POLYESTERS

    公开(公告)号:US20250059322A1

    公开(公告)日:2025-02-20

    申请号:US18724356

    申请日:2022-12-19

    Abstract: In an aspect, a method for reducing the molecular weight of a polyester comprises extruding a composition comprising a chain scission agent and a polyester in a molten state to form a modified polyester. The chain scission agent can comprise a C2-12 diol and can be present in an amount of 0.1 to 5 weight percent based on the total weight of the composition. The polyester can comprise a C2-12 alkyl phthalate polyester having a weight average molecular weight, Mwi, of 15,000 to 100,000 g/mol based on polystyrene standards. The modified polyester can have a weight average molecular weight, Mwf, of at least 5% less than the weight average molecular weight of the polyester.

    Process for the production of thermoplastic polyester

    公开(公告)号:US11021570B2

    公开(公告)日:2021-06-01

    申请号:US16474616

    申请日:2017-12-06

    Abstract: The present invention relates to a process for the production of a thermoplastic polyester using a reaction mixture comprising a dicarboxylic acid having a melting temperature of ≥200° C. wherein the dicarboxylic acid is introduced to the process in the form of particles having an average particle diameter of ≥100 μm. Such process results in a reduction of the polymerisation time. Furthermore, it allows for the production of thermoplastic polyesters having a desired balance of intrinsic viscosity and carboxylic end group content at a reduced polymerisation time.

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