Abstract: The invention provides methods and systems for manufacturing low-acid polyalkylene terephthalate, for example, polybutylene terephthalate (PBT). The invention also provides methods and systems for preparing macrocyclic polyester oligomer (MPO) from low-acid polyalkylene terephthalate. Finally, the invention provides methods and systems for preparing MPO via reaction of a diol and a dialkyl ester in an organic solvent to form non-isolated, low-acid polyalkylene terephthalate which undergoes cyclization (depolymerization) to form MPO.

Abstract: The invention provides methods and systems for manufacturing low-acid polyalkylene terephthalate, for example, polybutylene terephthalate (PBT). The invention also provides methods and systems for preparing macrocyclic polyester oligomer (MPO) from low-acid polyalkylene terephthalate. Finally, the invention provides methods and systems for preparing MPO via reaction of a diol and a dialkyl ester in an organic solvent to form non-isolated, low-acid polyalkylene terephthalate which undergoes cyclization (depolymerization) to form MPO.

Abstract: The invention relates to methods and systems for the use of an oligomer recyclate from a depolymerization product stream. The oligomer byproduct of a polyester depolymerization reaction can be used as a reactant in the formation of a polyester. For example, linear oligomer byproduct can be used as a reactant in a solution polymerization to form a low-acid polyalkylene terephthalate.

Abstract: The invention provides alternatives to traditional polycondensation processes for preparing copolymers. For example, in certain embodiments, the invention provides a process that includes an extrusion step and a solid state polymerization step to prepare high molecular weight block copolymer with a “hard block” contributed by a macrocyclic polyester oligomer (MPO) and a “soft block” contributed by a dihydroxyl-functionalized polymer, an oligoether, and/or a dimerized fatty acid (i.e. a polyol). The invention also provides new copolymer compositions made possible by the new processes—for example, copolymers of higher molecular weight, copolymers with higher weight ratio of soft block units to hard block units, copolymers made with higher molecular weight polyol, and copolymers with hard block units that are themselves random copolyesters of units contributed by a MPO and a cyclic ester.

Abstract: The invention relates to methods and systems for selective removal of catalyst residue from a depolymerization product stream without a water quench, as well as methods and systems for subsequent recovery of residual linear oligomer. The substantially metal-free and substantially water-free residual oligomer byproduct can then be advantageously used as recyclate in a process for preparing MPO. For example, the residual oligomer recyclate can be used as a reactant in the polymerization and subsequent depolymerization (cyclization) of low-acid polyester to form MPO.

Abstract: The invention provides alternatives to traditional polycondensation processes for preparing copolymers. For example, in certain embodiments, the invention provides a process that includes an extrusion step and a solid state polymerization step to prepare high molecular weight block copolymer with a “hard block” contributed by a macrocyclic polyester oligomer (MPO) and a “soft block” contributed by a dihydroxyl-functionalized polymer, an oligoether, and/or a dimerized fatty acid (i.e. a polyol). The invention also provides new copolymer compositions made possible by the new processes—for example, copolymers of higher molecular weight, copolymers with higher weight ratio of soft block units to hard block units, copolymers made with higher molecular weight polyol, and copolymers with hard block units that are themselves random copolyesters of units contributed by a MPO and a cyclic ester.

Abstract: Processes for isolating, formulating, and shaping macrocyclic oligoesters were developed which allow efficient production of macrocyclic oligoesters substantially free from solvent, which may include additives, fillers, and catalysts.

Abstract: Organo-titanate catalysts are prepared that are useful to catalyze depolymerization of a polyester to produce macrocyclic oligoesters substantially free from macrocyclic co-oligoesters.

Abstract: Macrocyclic oligoesters and compositions comprising macrocyclic oligoesters are prepared from intermediate molecular weight polyesters. In one embodiment, a diol is contacted with a dicarboxylic acid or a dicarboxylate in the presence of a catalyst to produce a composition comprising a hydroxyalkyl-terminated polyester oligomer. The hydroxyalkyl-terminated polyester oligomer is heated to produce a composition comprising an intermediate molecular weight polyester which preferably has a molecular weight between about 20,000 Daltons and about 70,000 Daltons. The intermediate molecular weight polyester is heated and a solvent is added prior to or during the heating process to produce a composition comprising a macrocyclic oligoester. An optional step is to separate the macrocyclic oligoester from the composition comprising the macrocyclic oligoester.

Abstract: Macrocyclic oligoesters and compositions comprising macrocyclic oligoesters are prepared from intermediate molecular weight polyesters. In one embodiment, a diol is contacted with a dicarboxylic acid or a dicarboxylate in the presence of a catalyst to produce a composition comprising a hydroxyalkyl-terminated polyester oligomer. The hydroxyalkyl-terminated polyester oligomer is heated to produce a composition comprising an intermediate molecular weight polyester which preferably has a molecular weight between about 20,000 Daltons and about 70,000 Daltons. The intermediate molecular weight polyester is heated and a solvent is added prior to or during the heating process to produce a composition comprising a macrocyclic oligoester. An optional step is to separate the macrocyclic oligoester from the composition comprising the macrocyclic oligoester.

Abstract: In one aspect, the invention relates to processes for producing substantially free-flowing shapes of macrocyclic oligoester, wherein the freshly-shaped macrocyclic oligoester is maintained at elevated temperature for a sufficient time. In certain embodiments, the shapes are heated in water, thereby avoiding agglomeration during the heating process itself. In another aspect, the invention relates to processes for removing solvent from a solution of macrocyclic oligoester using elevated temperature, reduced pressure, or both, thereby obviating the need for an anti-solvent to precipitate the macrocyclic oligoester from the solution. Other aspects of the invention related to shaping of macrocyclic oligoesters are presented as well.

Abstract: Concentrates of a carbon-based filler—such as carbon nanotubes, exfoliated graphite, and the like—and a macrocyclic polyester oligomer (also referred to herein as macrocyclic oligoester or MPO) are presented. When mixed with polymer, the MPO can act as a flow modifier, as well as a carrier for the carbon-based filler, allowing enhanced processability of the polymer-filler composite without adversely affecting the properties of the composite.

Abstract: The invention provides methods and formulations involving the use of promoters that accelerate the polymerization of macrocyclic polyester oligomers (MPOs). For example, in certain embodiments, the invention provides blends of macrocyclic polyester oligomer (MPO), catalyst, and promoter that are substantially stable at ambient temperature for a period of time. The blend material may be stored without premature polymerization of MPO or deactivation of catalyst. The invention also provides processes employing one-part, ready-to-polymerize blends that contain MPO, catalyst, and promoter, as well as processes in which the catalyst and promoter are used in separate streams and are contacted when it is desired to accelerate polymerization of MPO. Methods of the invention offer advantages in the manufacture of thermoplastic parts and composites, due at least in part to the unique properties of MPO.

Abstract: This invention relates generally to the use of macrocyclic polyester oligomers, and certain other cyclic oligomers, as additives in linear thermoplastics for improved flow and/or processibility. More particularly, in certain embodiments, the invention relates to compositions containing up to about 10 wt. % cyclic oligomer, and their use in manufacturing processes, such as injection molding operations.

Abstract: The invention provides intimate physical mixtures of macrocyclic polyester oligomer (MPO) and filler, as well as methods for their preparation and use. Improved dispersion of filler in a polymer matrix is achieved upon polymerization, and larger amounts of filler with high aspect ratio can be used. In one aspect, the invention provides mixtures of MPO with magnesium silicate. In another aspect, the invention provides a mixture of MPO, filler, and polymerization catalyst as a one-part, ready-to-polymerize material with a long shelf life. The one-part material can be used, for example, in the manufacture of parts without modification of existing processing equipment.

Abstract: This invention relates to single-component and multi-component catalytic systems using aryl titanates. Aryl titanate compounds are useful as catalysts and co-catalysts in single-component and multi-component catalytic systems (e.g., for the polymerization of macrocyclic oligoesters and the depolymerization of polyesters). Multi-component catalytic systems using aryl titanates allow increased versatility in applications such as liquid molding.

Abstract: Processes for isolating, formulating, and shaping macrocyclic oligoesters were developed which allow efficient production of macrocyclic oligoesters substantially free from solvent, which may include additives, fillers, and catalysts.

Abstract: The invention provides blends of macrocyclic polyester oligomer (MPO) with high-molecular-weight polymer and polymerization catalyst as friable, one-component, ready-to-polymerize materials with long shelf life. The invention also provides methods for preparation and use of the blend materials. The blends are used, for example, in the production of thermoplastics via low-pressure processes, such as rotational molding and powder coating, without modification of existing equipment. The blends are particularly useful where it is desired to exploit the ability to polymerize and crystallize MPO isothermally, but where the melt viscosity of unfilled MPO is too low for use in existing equipment.

Abstract: The invention provides blends of macrocyclic polyester oligomer (MPO) with high-molecular-weight polymer and polymerization catalyst as friable, one-component, ready-to-polymerize materials with long shelf life. The invention also provides methods for preparation and use of the blend materials. The blends are used, for example, in the production of thermoplastics via low-pressure processes, such as rotational molding and powder coating, without modification of existing equipment. The blends are particularly useful where it is desired to exploit the ability to polymerize and crystallize MPO isothermally, but where the melt viscosity of unfilled MPO is too low for use in existing equipment.

Abstract: The invention relates to methods and systems for the use of an oligomer recyclate from a depolymerization product stream. The oligomer byproduct of a polyester depolymerization reaction can be used as a reactant in the formation of a polyester. For example, linear oligomer byproduct can be used as a reactant in a solution polymerization to form a low-acid polyalkylene terephthalate.