Abstract: The present disclosure provides a semi-aromatic copolyamide, its preparation method, compositions, and a molded product thereof. The semi-aromatic copolyamide is formed from raw materials including diacid monomers and diamine monomers. The diacid monomers include aromatic diacid or derivatives of the aromatic diacid and aliphatic diacid. The diamine monomers include decamethylene diamine and pentamethylene diamine. The molar ratio of the decamethylene diamine to the pentamethylene diamine is in a range of 1:1 to 30:1.

Abstract: Disclosed are a long-carbon-chain polyamide resin composition and a continuous fiber reinforced long-carbon-chain polyamide composite material. The long-carbon-chain polyamide resin composition includes the following components in parts by weight: 81.8-99.8 parts by mass of long-carbon-chain bio-based polyamide 5X resin, 0.2-1.6 parts by mass of an antioxidant, 0-0.8 parts by mass of a lubricant, 0-15 parts by mass of a compatibilizer, and 0-0.8 parts by mass of a coupling agent. The continuous fiber reinforced long-carbon-chain polyamide composite material prepared on the basis of the long-carbon-chain polyamide resin composition has high fiber content and good mechanical properties, is recyclable and can be used in fields of aerospace, military, automotive materials, sports equipment, building materials, electronic appliances, etc.

Abstract: Provided are a flame-retardant polyamide glass fiber composition and a preparation method therefor. The flame-retardant polyamide glass fiber comprising 40-65 parts by mass of a polyamide resin, 25-40 parts by mass of glass fibers, 0-20 parts by mass of a flame retardant, 0.2-1 part by mass of an antioxidant and 0.1-2 parts by mass of other auxiliaries. The flame-retardant polyamide glass fiber composition provided in the present disclosure not only has a bio-based source, but also has a flame-retardant of V-0 in UL94 and excellent mechanical properties, and can be widely applied to the fields of various engineering plastics with high requirements for flame retardant effect and dimensional stability.

Abstract: The present disclosure provides a system for extracting long chain dicarboxylic acid, the system comprising: a primary membrane filtration unit, a first crystallization unit, a first separation unit, a first dissolution tank, a secondary membrane filtration unit, a second separation unit, a second crystallization unit and a third separation unit. By the system for extracting long chain dicarboxylic acid of an embodiment of the present invention, the resulted long chain dicarboxylic acid product has a high purity, very low and even no residual alkane residue, and organic solvent-free.

Abstract: The present invention provides a decanedioic acid produced by microbial fermentation process, in which the content of C10 aliphatic acid and C10 hydroxy aliphatic acid is maintained at a very low level. The present invention also provides a preparation method of the decanedioic acid and a polymer prepared by using the decanedioic acid as monomer. The decanedioic acid provided by the present invention is prepared by microbial fermentation process. The decanedioic acid product which is produced through the processes of microbial fermentation and separation has a higher purity, a higher thermal stability, and a lower impurity content. The decanedioic acid provided by the present invention could satisfy the requirements of high grade product of polyamide or polyester to produce polymer with excellent qualities.

Abstract: Provided microorganisms genetically modified to overexpress an imine/enamine deaminase to enhance the production of lysine and lysine derivatives by the microorganism. Also provided a method of generating such microorganism, and methods of producing lysine and lysine derivatives using the genetically modified microorganisms.

Abstract: This invention provides acid decarboxylase-prion subunit fusion polypeptides, nucleic acid sequences, expression vectors, and host cells expression such fusion polypeptides to produce various amino acids and derivatives of the amino acids such as polyamines.

Abstract: The invention is directed to a method of preparing a long chain dicarboxylic acid producing strain by using directed evolution and homologous recombination, a strain obtained by this method that is capable of producing a long chain dicarboxylic acid under an acidic condition and the use of the strain. In particular, the invention is directed to a method of preparing a long chain dicarboxylic acid producing strain by using directed evolution of CYP52A12 gene and homologous recombination, a strain obtained by this method that is capable of producing a long chain dicarboxylic acid under an acidic condition and the use of the strain.

Abstract: Provided are a Candida tropicalis strain Am2525, with the preservation number thereof being CCTCC NO: M 2019419, and a method for producing long-chain dicarboxylic acids by means of fermenting the strain. The method for producing the long-chain dicarboxylic acids comprises preparing a seed solution by means of the Candida tropicalis strain Am2525 and producing the long-chain dicarboxylic acids via fermentation of the seed solution. Compared with the parent, the Candida tropicalis strain Am2525 has an enhanced resistance to the toxicity of a substrate decane, improves the productivity of long-chain dicarboxylic acids, reduces the cost of production, subsequent separation and purification are simple, and the fermentation production process is easy to implement on a large scale.

Abstract: Disclosed are an industrial polyamide yarn, a preparation method therefor, and the use thereof. The raw materials for producing the industrial polyamide yarn include at least 1,5-pentanediamine and a linear aliphatic dibasic acid; or polyamide 5X obtained by the polymerization of 1,5-pentanediamine and a linear aliphatic dibasic acid as monomers. The industrial polyamide yarn according to an embodiment has the characteristics of a low water absorption, a good dimensional stability, a high fracture strength, and a good heat resistance.

Abstract: The present application discloses a polyamide 5X fiber, wherein raw materials for producing the polyamide 5X fiber comprise at least 1,5-pentane diamine and a long carbon chain diacid; or comprises a polyamide 5X obtained by the polymerization of 1,5-pentane diamine and a long carbon chain diacid as monomers. The 1,5-pentane diamine or the long carbon chain diacid are produced from bio-based raw materials by a fermentation process or an enzymatic conversion process; and the long carbon chain diacid is at least one of C6-20 aliphatic long carbon chain diacids. The long carbon chain diacid is at least one of C6-20 aliphatic long carbon chain diacids. The polyamide 5X fiber includes pre-oriented yarns, drawn textured yarns, fully drawn yarns, staple fibers, industrial yarns, continuous bulked filaments and monofilaments, preferably pre-oriented yarns, drawn textured yarns and/or fully drawn yarns.

Abstract: The present disclosure provides a polyamide 5X staple fiber, a preparation method and use thereof. The polyamide 5X staple fiber has a denier of 8.0-30.0D, a breaking strength of 2.0-6.0 cN/dtex, and an elongation at break of 30-100%. The polyamide 5X staple fiber has good mechanical properties and softness, and a blended wool yarn for manufacturing carpets with good mechanical properties, dyeability, and wear resistance can be obtained by using the polyamide 5X staple fiber.

Abstract: The present invention relates to the technical field of polyamide materials, and specifically relates to a polyamide sea-island fiber and a process for producing the same and the use thereof. In the polyamide sea-island fiber, the island component is a polyamide resin selected from one of polyamide 56, polyamide 510, polyamide 511, polyamide 512, polyamide 513, polyamide 514, polyamide 515 and polyamide 516, preferably polyamide 56 or polyamide 510; the sea component is one of polyethylene, low-density polyethylene, polystyrene, water-soluble polyesters, polyesters and polyurethanes, preferably polyethylene, low-density polyethylene or water-soluble polyester. The polyamide sea-island fiber of the present invention has better mechanical properties, better softness, good dyeing properties, high grade of dyeing grey scale, high dye uptake, high dyeing depth and high color fastness.

Abstract: Disclosed in the present invention is a polyamide 5X industrial yarn. The polyamide 5X industrial yarn has a heat-resistant break strength retention rate of 90% or more after being treated at 180° C. for 4 hrs; a heat-resistant break strength retention rate of 90% or more after being treated at 230° C. for 30 mins; and a dry heat shrinkage of 8.0% or less. The polyamide 5X industrial yarn is widely used in the fields of sewing threads, tire cords, air bag yarns, release cloth, krama, canvas, safety belts, ropes, fishing nets, industrial filter cloth, conveyor belts, parachutes, tents, bags and suitcases.

Abstract: The present invention relates to a long-chain dibasic acid with low content of long-chain dibasic acid impurity of shorter carbon chain, to the preparation of a long-chain dibasic acid producing strain by directed evolution of POX gene and homologous recombination, and to the production of a long-chain dibasic acid with low content of long-chain dibasic acid impurity of shorter carbon chain by using the strain. The present invention also relates to a strain containing a mutated promoter, wherein, when a long-chain dibasic acid is produced by fermentation of this strain, the content of the acid impurity of shorter carbon chain in the fermentation product is significantly reduced.

Abstract: The invention provides CadA polypeptides with mutations that increase activity in alkaline pH compared to the wild-type lysine decarboxylase. The invention also provides methods of generating such mutant polypeptides, microorganisms genetically modified to overexpress the mutant polypeptides, and methods of generating such microorganism.

Abstract: The present disclosure provides methods for isolating a long chain dicarboxylic acid such as a substantially pure or pure long chain dicarboxylic acid from a fermentation broth containing microbial cells.

Abstract: The invention provides microorganisms genetically modified to overexpress biofilm dispersal related polypeptides to enhance the production of lysine and lysine derivatives by the microorganism, method of generating such microorganism, and methods of producing lysine and lysine derivatives using the genetically modified microorganisms.

Abstract: The present invention provides a process for producing a high temperature resistant polyamide, the high temperature resistant polyamide and the use thereof. The process comprises: optionally concentrating a polyamide salt solution, and then conducting the following operations: heating and pressurizing to a pressure of P1, and maintaining the pressure, wherein the temperature of the system is T1 at the end of the pressure-maintenance; depressurizing to a pressure of P2, wherein the temperature of the system is T2 at the end of the depressurization; and evacuating, whereby a polyamide melt is obtained; wherein P1 is 0.8-4 MPa, T1 is 250-290° C., T1<T2 and (T2?T1)/(P1?P2)=5-75. The process for producing a high temperature resistant polyamide according to the present invention is simple to operate and reduces energy consumption.

Abstract: The present invention relates to the technical field of polyamide materials, and provides a polyamide 56 pre-oriented yarn and a polyamide 56 draw textured yarn with a low shrinkage in boiling water, a process for producing the same and a use thereof. The raw materials for producing the polyamide 56 fiber comprise 1,5-pentane diamine and adipic acid, or a polyamide 56 resin obtained by polymerizing 1,5-pentane diamine monomer and adipic acid monomer; wherein the polyamide 56 fiber has a shrinkage in boiling water of 9% or less, wherein the polyamide 56 fiber comprises a polyamide 56 pre-oriented yarn with a low shrinkage in boiling water and a polyamide 56 draw textured yarn with a low shrinkage in boiling water. The polyamide 56 fiber has good mechanical properties, dyeing uniformity and dimensional stability. The process for producing the polyamide 56 fiber does not require modification to existing equipments for texturing polyamide fibers and thus reduces production costs.