摘要:
The present invention generally relates to a method for manufacturing phase change material (PCM) pellets. The method includes providing a melt composition, including paraffin and a polymer. The paraffin has a melt point of between about 10° C. and about 50° C., and more preferably between about 18° C. and about 28° C. In one embodiment, the melt composition includes various additives, such as a flame retardant. The method further includes forming the melt composition into PCM pellets. The method further may include the step of cooling the melt to increase the melt viscosity before pelletizing. Further, PCM compounds are provided having an organic PCM and a polymer. Methods are provided to convert the PCM compounds into various form-stable PCMs. A method of coating the PCMs is included to provide PCMs with substantially no paraffin seepage and with ignition resistance properties.
摘要:
A particulate poly(lactic-co-glycolic) acid (PLGA) is provided. The particulate PLGA comprises a poly(lactic-co-glycolic) acid (PLGA), and has an average volume-based particle diameter of 80 nm or less and a relative span factor (R.S.F.) satisfying the following formula (1): 0
摘要:
Certain polyamide beads or granules are useful as a sustaining material for underground natural or artificial cracks of the earth's crust essentially employed for the extraction of hydrocarbons such as crude oil or natural gas; such polyamide beads have a spherical or ellipsoidal shape and have a surface free of concave portions, advantageously having a uniform shape, and having a mean diameter lower than or equal to 1.7 mm and a porosity lower than 0.1 ml/g, and are produced using a particular cutting device/extruder.
摘要:
Speriodal polymer beads having a uniform size are prepared by polymerizing uniformly sized monomer droplets formed by dispersing a polymerizable monomer phase over a cross-flow membrane into an aqueous phase. A shear force is provided at a point of egression of the polymerizable monomer phase into the aqueous phase, the direction of shear substantially perpendicular to the direction of egression of the monomer phase. The polymer beads can be employed in applications where beads having uniform diameters of 10 to 180 μm are useful.
摘要:
A method and a device for producing superficially crystalline spherical granules by means of air-cooled hot die face pelletizing in a cutting chamber. A crystallizable plastic material can be melted and then extruded through a perforated plate. During the air-cooled hot die face pelletizing, at least one cutting blade can be moved relative to the perforated plate. The perforated plate can be temperature-controlled while maintaining a viscosity of the plastic material within nozzle openings. A superficial cooling to a crystal nucleation temperature of the dry-cut granules is performed by means of a centripetally inflowing process gas. The crystal nucleation temperature is below an optimum crystal growth temperature and above a glass transition temperature. By controlling the quantity of process gas at an adiabatic temperature, an average granule temperature is maintained in a range of an optimum crystal growth temperature.
摘要:
A composite material that includes a layer of reinforcing fibres impregnated with a curable resin matrix and a plurality of electrically conductive composite particles positioned adjacent or in proximity to the reinforcing fibres. Each of the electrically conductive composite particles is composed of a conductive component and a polymeric component, wherein the polymeric component includes one or more polymers that are initially in a solid phase and are substantially insoluble in the curable resin, but is able to undergo at least partial phase transition to a fluid phase during a curing cycle of the composite material.
摘要:
Provided are: a powdered material for slush molding; and a manufacturing process therefor. The powdered material is less odorous, exhibits excellent powder fluidity, and does not suffer from troubles resulting from the sliding-down or agglomeration of a pigment even when the resin particles have been pigmented on the surfaces thereof. Thus, the powdered material ensures high productivity. The powdered material is a powdered polyurethane urea resin composition which comprises (D) a polyurethane urea resin that has a total content of bimolecular condensate of acetone, bimolecular condensate of methyl ethyl ketone, and bimolecular condensate of methyl isobutyl ketone of 1,000 ppm or less and (N) an additive, wherein the polyurethane urea resin (D) takes the form of thermoplastic polyurethane urea resin particles (P) that have a volume-mean particle diameter of 20 to 500 μm and that have protrusions and recesses on the surfaces. The powdered polyurethane urea resin composition is manufactured by a manufacturing process which includes a step of mixing (A) an isocyanato-terminated urethane prepolymer with (B) an alicyclic diamine and/or an aliphatic diamine in an aqueous medium by stirring to form the resin particles (P).
摘要:
The invention relates to polymeric fibers and a process of preparing polymeric fibers. The process comprises the steps of synthesizing a composite of thermotropic liquid crystalline polymer (TLCP) comprising multi-walled carbon nanotubes (MWNTs), and spinning the composite to form composite fibers. Specifically, the MWNTs are incorporated at a very low concentration. It is demonstrated that the as-spun TLCP/MWNTs composite fibers demonstrated significantly enhanced mechanical properties as compared with the control TLCP fibers without MWNTs. Fibers having 0.3 wt % MWNTs (C-3) demonstrated an increase of tensile modulus and strength by 38% and 32%, respectively, when compared with the control TLCP fiber without MWNTs.
摘要:
In one aspect, the present invention provides a process for forming polymeric nanoparticles, which comprises using a static mixer to create a mixed flowing stream of an anti-solvent, e.g., by introducing a liquid anti-solvent into a static mixer, and introducing a polymer solution into the mixed flowing anti-solvent stream such that controlled precipitation of polymeric nanoparticles occurs. The nanoparticles can then be separated from the anti-solvent stream.
摘要:
Polymer pellets are formed using air to influence the separation of polymer from a polymer melt. In accordance with one or more embodiments, a polymer material is extruded through a nozzle to form a polymer melt extending from the nozzle. A non-uniform thickness is generated in the polymer melt using a gas or gasses to apply a drag force to the polymer melt. This drag force reduces a thickness of a portion of the polymer melt adjacent the nozzle, and the polymer melt is fractured into discrete droplets at the reduced thickness. The discrete droplets are then solidified to form pellets.