The present invention relates to a method for producing an aliphatic polyester carbonate, the polyester carbonate itself, and to moulding compositions and moulded articles containing the polyester carbonate. The claimed method is characterised in particular in that the method comprises three steps and the last step is a melt transesterification method in the presence of two catalysts.

The present invention relates to a method for producing an aliphatic polyester carbonate, the polyester carbonate itself, and to moulding compositions and moulded articles containing the polyester carbonate. The claimed method is characterised in particular in that the method comprises three steps and the last step is a melt transesterification method in the presence of two catalysts.

A catalytic composition for preparing a polyethylene terephthalate (PET) resin is provided. The catalytic composition comprises a polycondensation catalyst and cesium tungsten oxide (Cs.sub.xWO.sub.3-yCl.sub.y), and 0<x≦1 and 0≦y≦0.5. A PET resin prepared by the catalytic composition above is also provided. The PET resin comprises 2-80 ppm of cesium tungsten oxide. This catalytic composition can solve the problems of slow solid-state polymerization rate of the PET preparation and thus the long preparation time, as well as yellowing. Moreover, the PET resin can absorb infrared radiation.

The present invention relates to a process for preparing a polyester carbonate on the basis of aliphatic diacids and aliphatic diols and to the polyester carbonate prepared according to the process and to a moulding mass and moulding body containing the polyester carbonate. The process according to the invention is a direct synthesis in which all structural elements forming the subsequent polyester carbonate are already present as monomers in the first process step and in which two catalysts are used.

The present invention relates to a process for preparing a polyester carbonate on the basis of aliphatic diacids and aliphatic diols and to the polyester carbonate prepared according to the process and to a moulding mass and moulding body containing the polyester carbonate. The process according to the invention is a direct synthesis in which all structural elements forming the subsequent polyester carbonate are already present as monomers in the first process step and in which two catalysts are used.

The disclosure discloses a high-frequency transmission LCP film and preparation method thereof. The preparation method comprises the following steps: (1) separately performing acetylation on monomers to obtain acetylated monomers; (2) performing high-temperature polymerization on the acetylated monomers, phenolic resin, acetic anhydride and zinc acetate, and performing pulverization to obtain liquid crystal copolyester; (3) ball milling the liquid crystal copolyester, an inorganic filler, a silane coupling agent and a glass fiber and mixing to obtain a mixture; and melt-plasticizing the mixture to form a film after cooling, performing longitudinal and transverse synchronous stretching, then winding and slitting the film to obtain a high-frequency transmission LCP film. In the disclosure, by adjusting the type and ratio of acetylated monomers and adding phenolic resin, a regular fibrous structure is obtained; and by adding an inorganic filler, a silane coupling agent and glass fibers, its mechanical properties are enhanced and dielectric loss is reduced, thereby obtaining an LCP film with low dielectric constant and low dielectric loss factor which can be applied to the fields of electronics, electricity, optical fiber, 5G communication and the like.

The disclosure discloses a high-frequency transmission LCP film and preparation method thereof. The preparation method comprises the following steps: (1) separately performing acetylation on monomers to obtain acetylated monomers; (2) performing high-temperature polymerization on the acetylated monomers, phenolic resin, acetic anhydride and zinc acetate, and performing pulverization to obtain liquid crystal copolyester; (3) ball milling the liquid crystal copolyester, an inorganic filler, a silane coupling agent and a glass fiber and mixing to obtain a mixture; and melt-plasticizing the mixture to form a film after cooling, performing longitudinal and transverse synchronous stretching, then winding and slitting the film to obtain a high-frequency transmission LCP film. In the disclosure, by adjusting the type and ratio of acetylated monomers and adding phenolic resin, a regular fibrous structure is obtained; and by adding an inorganic filler, a silane coupling agent and glass fibers, its mechanical properties are enhanced and dielectric loss is reduced, thereby obtaining an LCP film with low dielectric constant and low dielectric loss factor which can be applied to the fields of electronics, electricity, optical fiber, 5G communication and the like.

##STR00001##

A method for producing an oligomeric polyethylene terephthalate (PET) substrate for use in a recycled PET (rPET) manufacturing process comprises adding recycled bis-hydroxylethyleneterephthalate (rBHET) or a higher molecular weight oligomer derived from rBHET and water to a reaction zone and reacting the rBHET and water in the reaction zone to produce an oligomeric PET substrate represented by the Formula (I): wherein R1 is a carboxyl end group or a hydroxyl end group, R2 is a carboxyl end group or a hydroxyl end group, and n is a degree of polymerisation (Dp).

##STR00001##

A method for producing an oligomeric polyethylene terephthalate (PET) substrate for use in a recycled PET (rPET) manufacturing process comprises adding recycled bis-hydroxylethyleneterephthalate (rBHET) or a higher molecular weight oligomer derived from rBHET and water to a reaction zone and reacting the rBHET and water in the reaction zone to produce an oligomeric PET substrate represented by the Formula (I): wherein R1 is a carboxyl end group or a hydroxyl end group, R2 is a carboxyl end group or a hydroxyl end group, and n is a degree of polymerisation (Dp).

An end and monomer functionalized poly(propylene fumarate) polymer and methods for preparing this polymer, comprising isomerized residue of a maleic anhydride monomer and a functionalized propylene oxide monomer according to the formula: ##STR00001## where n is an integer from more than 1 to 100; R is the residue of an initiating alcohol having a propargyl, norbornene, ketone or benzyl functional group; and R′ is a second functional group selected from the group consisting of propargyl groups, 2-nitrophenyl groups, and combinations thereof are disclosed. The end and monomer functional groups allow for post-polymerization modification with bioactive materials using “click” chemistries and use of the polymer for a variety of applications in medical fields, including, for example, 3-D printed polymer scaffold.