Abstract: A method for preparing a graphene-modified natural rubber (NR) with an interfacial interaction based on a free radical annihilation reaction is provided. In the process of reducing graphene oxide (GO), a free radical scavenger is loaded on a surface of reduced graphene oxide (rGO). An rGO-modified NR composite is prepared through aqueous synergistic aggregating precipitation process and mechanical blending. The free radical scavenger loaded on the rGO particles are capable of annihilating macromolecular free radicals generated by NR macromolecules due to an action of heat and/or force during the mixing and milling processes, an enhancement effect of the free radical annihilation reaction on an interfacial interaction between graphene and NR is great, so as to obtain a graphene-modified NR composite with improved strength and toughness.

Abstract: A method for preparing a uniformly-cured solid loading tire from a high-modulus graphene oxide/natural rubber composite is provided. A high-modulus graphene oxide/carbon black/natural rubber mixture sheet and two high-viscosity graphene oxide/carbon black/natural rubber mixture sheets are prepared, where a weight ratio of graphene oxide to natural rubber to carbon black to an interface modifying agent to an anti-aging agent to an antioxidant to a vulcanization accelerator to an activator to a softener to a vulcanizing agent is 0.5-5:100:40-120:1-20:1-10:1-10:1-20:1-20:1-20:1-20. The high-modulus rubber mixture sheet is sandwiched between the two high-viscosity rubber mixture sheets to form a sandwich-structure rubber mixture laminate, which is then processed into a strip. The strip is wound along a surface of a hub of a loading wheel, and then the hub is transferred to a mold for vulcanization to obtain the desired tire.

Abstract: A lightweight absorption-transmission integrated metamaterial to electromagnetic waves with polarization stability and wide-incident-angle stability, which has a symmetric structure including at least one square frequency-selective structure-unit arranged periodically. The square frequency-selective structure-unit includes a first dielectric substrate, a metal array structure layer, a second dielectric substrate, a first carbon-based conductive film array structure layer, a third dielectric substrate, and a second carbon-based conductive film array structure layer, which are laminated in sequence with the first dielectric substrate as the bottom. A method for preparing such lightweight absorption-transmission metamaterial to electromagnetic waves is also provided.

Abstract: An optimizing method for a molding process of a part made of a fiber-reinforced polymer composite is provided. A finite element method is adopted to perform thermochemical analysis of a macroscopic model of the part and thermomechanics analysis of a microscopic model of the part, so as to simulate temperature gradient, curing degree, and residual stress of the part during the molding process. A genetic algorithm is executed, with simultaneous minimization of temperature gradient, molding time, and residual stress as an optimization goal and a curing process curve as a parameter variable, to achieve the simultaneous multi-objective optimization of molding process parameters, so as to obtain an optimized molding process.

Abstract: An high-velocity impact-resistant wave-transparent composite, including an upper composite layer, a lower composite layer, and a bio-inspired nacre-like toughening structure arranged therebetween. The toughening structure has a soft-hard alternating nacre-like structure, and is made from a low dielectric constant sheet material and a resin. The upper composite layer and the lower composite layer are each independently made of a fiber-reinforced resin composite, a foam material, or a honeycomb material. A preparation method of the high-velocity impact-resistant wave-transparent composite is further provided.

Abstract: A method for preparing a weathered coal-derived humic acid/urea-formaldehyde slow-release fertilizer granule by reactive extrusion process with depolymerization-activation-polycondensation trinity is provided. In an alkaline environment, paraformaldehyde is depolymerized into formaldehyde small molecules, which react with urea to form monohydroxymethylurea and dihydroxymethylurea. Under the strong shearing action of screws of the twin-screw reactive extruder, the macromolecular weathered coal-derived humic acid is depolymerized into relatively small molecule weathered coal-derived humic acid, and abundant active carboxyl groups are exposed, some of which immediately undergo dehydration condensation with —NH2 on the urea-formaldehyde molecule produced by the polycondensation of hydroxymethylurea during the reactive extrusion process to generate weathered coal-derived humic acid/urea-formaldehyde and its granules.

Abstract: A lightweight, low-thickness, durable, and reliable multi-band radar stealth-bulletproof integrated metamaterial includes a ceramic layer, an ultrahigh molecular weight polyethylene (UHMWPE) fiber composite bulletproof layer, a graphene-based metamaterial filter layer, an UHMWPE fiber composite attenuation layer, and a carbon fiber composite reflective layer stacked in sequence. The two UHMWPE fiber composite layers are configured to attenuate radar waves. The circuit resonance of the graphene-based metamaterial filter layer is configured to generate a passband and a stopband simultaneously. The bulletproof layer and the attenuation layer are controlled by the graphene-based metamaterial filter layer in terms of working conditions in different radar frequency bands to establish a structure capable of generating ?/4 resonance at both low and high frequencies, so as to arrive at a stealth-bulletproof integrated metamaterial with small thickness and excellent dual-band radar wave absorption capability.

Abstract: A lightweight, ballistic and blast-resistant multi-phase composite armor material based on a high-toughness heterogeneous interfacial layer, including a crack-arresting layer, a bullet-breaking layer, an energy-absorbing layer, and a support layer. The crack-arresting layer, the bullet-breaking layer, the energy-absorbing layer, and the support layer are stacked in sequence from a bullet-accepting side to the inside. Adjacent two layers are bonded with an adhesive film layer. The crack-arresting layer and the support layer are both made of a carbon fiber composite. The bullet-breaking layer is made of ceramic. The energy-absorbing layer is made of an ultra-high molecular weight polyethylene fiber composite. The adhesive film layer is made of a high-toughness heterogeneous interfacial adhesive.

Abstract: An efficient microwave-assisted preparation method with one-step simultaneous reduction/embedding of a metal monatomic-doped reduced graphene oxide dielectric material. A metal salt aqueous solution is added to a graphene oxide aqueous dispersion to obtain a mixed dispersion. The mixed dispersion is mechanically stirred, such that the metal salt fully interacts with the graphene oxide, and the metal ions are uniformly loaded on a surface of the graphene oxide sheets through the interaction between metal ions and the oxygen-containing functional groups of the graphene oxide. The mixed dispersion is freeze-dried to obtain a metal salt/graphene oxide complex, which is subjected to a microwave treatment in the presence of an initiator in a microwave oven to allow reduction to obtain the metal monatomic-doped reduced graphene oxide dielectric material. An application of the metal monatomic-doped reduced graphene oxide dielectric material is also provided.

Abstract: A method of producing a thermoplastic starch by an in-situ reactive extrusion plasticization process and a method for preparing a starch/polymer blend by an in-situ reactive extrusion plasticization and compatibilization process. In the method, a plasticizer reaction precursor (or a plasticizing compatibilizer reaction precursor) is mixed with starch to adhere to the surface of the starch or enter the starch to break the intermolecular and intramolecular hydrogen bonds of the starch. Then a mixture of the plasticizer reaction precursor (or the plasticizing compatibilizer reaction precursor) and starch is subjected to extrusion to produce the thermoplastic starch (or the starch/polymer blend), where the reaction precursor undergoes an in-situ reaction on the surfaces of the starch and in the starch to form a macro-molecular plasticizer (or a plasticizing compatibilizer) to plasticize starch or provide plasticizing and compatibilizing effect on the starch/polymer blend.

Abstract: An efficient microwave-assisted preparation method with one-step simultaneous reduction/embedding of a metal monatomic-doped reduced graphene oxide dielectric material. A metal salt aqueous solution is added to a graphene oxide aqueous dispersion to obtain a mixed dispersion. The mixed dispersion is mechanically stirred, such that the metal salt fully interacts with the graphene oxide, and the metal ions are uniformly loaded on a surface of the graphene oxide sheets through the interaction between metal ions and the oxygen-containing functional groups of the graphene oxide. The mixed dispersion is freeze-dried to obtain a metal salt/graphene oxide complex, which is subjected to a microwave treatment in the presence of an initiator in a microwave oven to allow reduction to obtain the metal monatomic-doped reduced graphene oxide dielectric material. An application of the metal monatomic-doped reduced graphene oxide dielectric material is also provided.

Abstract: A method for preparing a weathered coal-derived humic acid/urea-formaldehyde slow-release fertilizer granule by reactive extrusion process with depolymerization-activation-polycondensation trinity is provided. In an alkaline environment, paraformaldehyde is depolymerized into formaldehyde small molecules, which react with urea to form monohydroxymethylurea and dihydroxymethylurea. Under the strong shearing action of screws of the twin-screw reactive extruder, the macromolecular weathered coal-derived humic acid is depolymerized into relatively small molecule weathered coal-derived humic acid, and abundant active carboxyl groups are exposed, some of which immediately undergo dehydration condensation with —NH2 on the urea-formaldehyde molecule produced by the polycondensation of hydroxymethylurea during the reactive extrusion process to generate weathered coal-derived humic acid/urea-formaldehyde and its granules.

Abstract: This disclosure relates to slow- and controlled-release fertilizers (S-CRF), and more particularly to a microelement amino acid chelate-urea formaldehyde (UF) slow-release fertilizer and a method for preparing the same by reactive extrusion. The microelement amino acid chelate-UF slow-release fertilizer includes a biodegradable UF polymer and a microelement amino acid chelate. The macromolecular chains of the biodegradable UF polymer interpenetrate in the cross-linked network structure of the chelate, so as to form a polymer composite with a semi-interpenetrating network structure.

Abstract: A sulfonated lignin as a by-product of papermaking wood pulp/urea-formaldehyde (UF) fertilizer and a method for preparing the same by a reactive extrusion and granulation process are provided. The method includes: mixing a hydroxymethylated sulfonated lignin solution with a hydroxymethyl-urea solution followed by feeding into a reaction-extrusion integrated machine and reaction at a preset temperature for a preset time; subjecting the reaction mixture to extrusion through a twin-screw extruder to obtain a strip product; and drying the strip product followed by granulation to obtain a sulfonated lignin as a by-product of papermaking wood pulp/UF fertilizer columnar particles. Sulfonated lignin molecules are introduced to the main chain of the UF macromolecules to reduce the polymerization degree and crystallinity of the UF fertilizer, so as to regulate the nitrogen release rate.

Abstract: This disclosure relates to slow- and controlled-release fertilizers (S-CRF), and more particularly to a microelement amino acid chelate-urea formaldehyde (UF) slow-release fertilizer and a method for preparing the same by reactive extrusion. The microelement amino acid chelate-UF slow-release fertilizer includes a biodegradable UF polymer and a microelement amino acid chelate. The macromolecular chains of the biodegradable UF polymer interpenetrate in the cross-linked network structure of the chelate, so as to form a polymer composite with a semi-interpenetrating network structure.

Abstract: A high wear-resistant graphene-modified natural rubber and a preparation thereof. The graphene-modified natural rubber is prepared from 100 parts by weight of a modified natural rubber blend, A parts by weight of modified graphene oxide, 35-65 parts by weight of wear-resistant carbon black, 5-20 parts by weight of a wear-resistant filler, 2-7 parts by weight of zinc oxide, 1-4 parts by weight of stearic acid, 1-4 parts by weight of poly(1,2-dihydro-2,2,4-trimethylquinoline), 1-4 parts by weight of N-isopropyl-N?-phenyl-p-phenylenediamine, 1-4 parts by weight of a vulcanization accelerator, 1-2 parts by weight of sulphur, 0.1-3 parts by weight of a compatibilizer and 1-7 parts by weight of rubber processing oil, where A is greater than 0 and equal to or less than 3.

Abstract: A device for determining degradation rate of biodegradable polymers in soil, including a micro compressed air pump, a first CO2 absorption vessel filled with dry soda lime or an aqueous strong alkali solution, a CO2 indicator vessel filled with a barium hydroxide solution, a hollow leaching device, a second CO2 absorption vessel and a third CO2 absorption vessel connected in sequence through connecting pipes. A top of the hollow leaching device is provided with an end cover. An external water distributor filled with a leaching solution and a mechanical stirring device is arranged above the end cover. The external water distributor is in communication with an inner cavity of the hollow leaching device through a pipeline. A stirring shaft of the mechanical stirring device extends into the inner cavity. A stirring shaft is provided with a stirring paddle.

Abstract: A method for preparing a graphene-containing ultra-fine powdered natural rubber masterbatch, including: mixing a diluted graphene oxide dispersion with an anionic surfactant to obtain a modified graphene oxide dispersion; mixing the modified graphene oxide dispersion with a natural rubber latex suspension to obtain a mixed emulsion; and subjecting the mixed emulsion to spray drying to obtain the ultra-fine powdered natural rubber masterbatch with a particle size of less than 5 ?m. This application further provides a method for preparing a graphene-modified natural rubber nanocomposite, including: mixing the ultra-fine powdered natural rubber masterbatch with natural rubber block, and carbon black.

Abstract: An injection mold for a high-aspect-ratio double-layer cylindrical plastic part and a molding method using the same. The injection mold includes a support base plate. A movable mold fixing frame and a movable mold base plate are arranged at the middle of a lower surface of the support base plate through positioning screws. A lower core mold is matchingly provided at a center of an upper surface of the support base plate, and is provided with a lower semicircular cavity for accommodating an outer die barrel. One side of the lower semicircular cavity is open, and the other side is provided with a first end wall which is provided with a lower semicircular notch for an inner die rod to pass through. An upper surface of the lower core mold is provided with a positioning protrusion, a lower feeding groove, and a remaining groove.

Abstract: This application relates to natural rubber (NR) composites, and more specifically to a method of preparing a graphene/natural rubber composite. In the method provided herein, nano-silica loaded graphene oxide (SiO2-GO) is formed by electrostatic interaction between silica and graphene oxide (GO), and then the SiO2-GO is added to natural rubber (NR) latex to obtain a SiO2-GO/NR masterbatch by aqueous phase synergistic aggregation-precipitation process. The SiO2-GO/NR masterbatch is subjected to mechanical blending and vulcanization to obtain the graphene/NR composite.