Abstract: A flame-retardant antimicrobial agent is a polymer microsphere with the surface grafted thereof with a guanidine salt. The polymer microsphere has a cross-linked structure composed of a structural unit A derived from maleic anhydride, a structural unit B derived from a monomer M, and a structural unit C derived from a cross-linking agent. The monomer M is selected from a C4-C9 aliphatic olefin or a mixture thereof, and the guanidine salt comprises at least one guanidine salt having the property of flame resistance. The flame-retardant antimicrobial agent has both a good antimicrobial effect and a good flame-retardant effect. A flame-retardant antimicrobial thermoplastic resin composition containing the flame-retardant antimicrobial agent also has a good flame-retardant and antimicrobial performance and a good overall performance.

Abstract: A method for preparing a polyolefin resin powder has the steps of a) heat dissolving a polyolefin resin in an organic solvent having a solubility parameter less than or equal to the solubility parameter of the polyolefin resin to obtain a polyolefin resin solution; b) cooling the polyolefin resin solution to precipitate a solid, thereby obtaining a solid-liquid mixture; c) optionally adding an adjuvant to the solid-liquid mixture and mixing; and d) conducting solid-liquid separation and drying to obtain a polyolefin resin powder suitable for selective laser sintering. The difference between the solubility parameters of the organic solvent and of the polyolefin resin is within 0-20% of the solubility parameter of the polyolefin resin. The polyolefin resin powder obtained according to this method has good antioxidant property, good powder flowability, moderate size, smooth surface, suitable bulk density, and suitable dispersibility and particle size distribution.

Abstract: A method for preparing an aliphatic polyester resin powder includes the steps of a) heat dissolving a crystalline aliphatic polyester resin in an organic solvent to obtain an aliphatic polyester resin solution; b) cooling the aliphatic polyester resin solution to precipitate a solid, thereby obtaining a solid-liquid mixture; c) optionally adding an adjuvant to the solid-liquid mixture and mixing; and d) conducting solid-liquid separation and drying to obtain an aliphatic polyester resin powder suitable for selective laser sintering. The crystalline aliphatic polyester resin powder obtained has good antioxidant property, good powder flowability, moderate size, smooth surface, suitable bulk density, and suitable dispersibility and particle size distribution. The aliphatic polyester resin powder is particularly suitable for selective laser sintering method.

Abstract: A method for preparing a polyolefin resin powder has the steps of a) heat dissolving a polyolefin resin in an organic solvent having a solubility parameter less than or equal to the solubility parameter of the polyolefin resin to obtain a polyolefin resin solution; b) cooling the polyolefin resin solution to precipitate a solid, thereby obtaining a solid-liquid mixture; c) optionally adding an adjuvant to the solid-liquid mixture and mixing; and d) conducting solid-liquid separation and drying to obtain a polyolefin resin powder suitable for selective laser sintering. The difference between the solubility parameters of the organic solvent and of the polyolefin resin is within 0-20% of the solubility parameter of the polyolefin resin. The polyolefin resin powder obtained according to this method has good antioxidant property, good powder flowability, moderate size, smooth surface, suitable bulk density, and suitable dispersibility and particle size distribution.

Abstract: A method for preparing an aliphatic polyester resin powder includes the steps of a) heat dissolving a crystalline aliphatic polyester resin in an organic solvent to obtain an aliphatic polyester resin solution; b) cooling the aliphatic polyester resin solution to precipitate a solid, thereby obtaining a solid-liquid mixture; c) optionally adding an adjuvant to the solid-liquid mixture and mixing; and d) conducting solid-liquid separation and drying to obtain an aliphatic polyester resin powder suitable for selective laser sintering. The crystalline aliphatic polyester resin powder obtained has good antioxidant property, good powder flowability, moderate size, smooth surface, suitable bulk density, and suitable dispersibility and particle size distribution. The aliphatic polyester resin powder is particularly suitable for selective laser sintering method.

Abstract: A polyethylene composition comprising an ethylene/?-olefin copolymerized linear low density polyethylene, wherein the polyethylene composition has a Mw of from 100,000 g/mol to 200,000 g/mol, a Mw/Mn of from 4.0 to 9.0, a Mz/Mw of from 4.0 to 7.0, and a Mz+1/Mw of from 4.5 to 13.5, is provided. A film formed of the polyethylene composition is also provided.

Abstract: A polyethylene composition comprising an ethylene/?-olefin copolymerized linear low density polyethylene, wherein the polyethylene composition has a Mw of from 100,000 g/mol to 200,000 g/mol, a Mw/Mn of from 4.0 to 9.0, a Mz/Mw of from 4.0 to 7.0, and a Mz+1/Mw of from 4.5 to 13.5, is provided. A film formed of the polyethylene composition is also provided.