Abstract: The present invention relates to a kind of biodegradable polyester and its preparation method, which belongs to the field of biodegradable co-polyester product technology. The number-average molecular weight of the biodegradable polyester material under this invention is 6000-135000 g/mol, the molecular weight distribution is 1.2-6.5, and the range of crystallization temperature is 15° C.-105° C., which could overcome the disadvantages of existing technical products and can be processed into membrane materials, sheet materials and foam materials. During processing, the picking property will be dramatically changed with the appearance quality improved; after heat resistance is improved, this new type of polyester material could also be applied to the processing course with long cycles, for example, the injection processing course, and the biodegradable aliphatic/aromatic polyester materials provided by this invention has excellent mechanical properties.

Abstract: The present invention discloses a thermoplastic flame-retardant alloy and a method for preparing it, composed of the following components as below (parts by weight): 5-94 parts of ABS resin, 3-94 parts of polyester or co-polyester or the mixture of both, 1-50 parts of brominated flame retardant, 1-10 parts of flame-retardant aid, 0.001-30 parts of chlorinated polyethylene (CPE), 0.001-2 parts of anti-dripping agent and 0.1-6 parts of processing aid. Comparing with the ABS flame retardant presenting the prior art, the thermoplastic flame-retardant alloy features better glossiness, scratch resistance, stronger ultraviolet radiation resistance and better mechanical property, thus making up for the disadvantage that the flame-retardant ABS is prone to become yellow on some occasions with high weatherability requirements. Furthermore, the preparation method of the thermoplastic flame-retardant alloy for the present invention is successive, stable and feasible.

Abstract: The present invention relates to a semi-aromatic polyamide and a method for preparing it with low wastewater discharge. The semi-aromatic polyamide for the present invention is obtained by introducing aromatic dicarboxylic acid, aliphatic diamine containing 4˜14 carbon atoms and the wastewater generated during the previous prepolymerization into an autoclave for prepolymerization reaction and then further polymerizing the prepolymer. In this preparation method, the wastewater generated during polymerization is recycled, thus greatly reducing the wastewater discharge; the raw materials in the wastewater are effectively recycled, thus improving the utilization rate of raw materials; meanwhile, the diamine in the wastewater compensates that lost along with water discharge during prepolymerization, thus ensuring the Mole ratio balance between dicarboxylic acid monomer and diamine monomer.

Abstract: The present invention relates to a kind of biodegradable polyester and its preparation method, which belongs to the field of biodegradable co-polyester product technology. The number-average molecular weight of the biodegradable polyester material under this invention is 6000-135000 g/mol, the molecular weight distribution is 1.2-6.5, and the range of crystallization temperature is 15° C.-105° C., which could overcome the disadvantages of existing technical products and can be processed into membrane materials, sheet materials and foam materials. During processing, the picking property will be dramatically changed with the appearance quality improved; after heat resistance is improved, this new type of polyester material could also be applied to the processing course with long cycles, for example, the injection processing course, and the biodegradable aliphatic/aromatic polyester materials provided by this invention has excellent mechanical properties.

Abstract: The present invention discloses a thermoplastic flame-retardant alloy and a method for preparing it, composed of the following components by the shares and weights as below: 5-94 shares of ABS resin, 3-94 shares of polyester or co-polyester or the mixture of both, 1-50 shares of brominated flame retardant, 1-10 shares of synergistic flame-retardant, 0.001-30 shares of chlorinated polyethylene (CPE), 0.001-2 shares of anti-dripping agent and 0.1-6 shares of processing aid. Comparing with the ABS flame retardant presenting the prior art, the thermoplastic flame-retardant alloy features better glossness, scratch resistance, stronger ultraviolet radiation resistance and better mechanical property, thus making up for the disadvantage that the flame-retardant ABS is prone to become yellow on some occasions with high weatherability requirements. Furthermore, the preparation method of the thermoplastic flame-retardant alloy for the present invention is successive, stable and feasible.

Abstract: The present invention relates to a semi-aromatic polyamide and a method for preparing it with low wastewater discharge. The semi-aromatic polyamide for the present invention is obtained by introducing aromatic dicarboxylic acid, aliphatic diamine containing 4˜14 carbon atoms and the wastewater generated during the previous prepolymerization into an autoclave for prepolymerization reaction and then further polymerizing the prepolymer. In this preparation method, the wastewater generated during polymerization is recycled, thus greatly reducing the wastewater discharge; the raw materials in the wastewater are effectively recycled, thus improving the utilization rate of raw materials; meanwhile, the diamine in the wastewater compensates that lost along with water discharge during prepolymerization, thus ensuring the Mole ratio balance between dicarboxylic acid monomer and diamine monomer.