7results about How to "Avoid over-crosslinking" patented technology

The present application relates to the technical field of resin, in particular to a conductive polypropylene composite material and a preparation method thereof.In view of the problems of poor processing fluidity, easy shear damage of conductive network and deterioration of mechanical properties caused by high filling of conductive filler in the prior art, the present application realizes the low volume resistivity, high melt flow rate and excellent mechanical toughness by the solid phase pre-coating technology, and effectively balances the conductivity, processability and strength.

The invention relates to light dehydrofluorination modified PVDF (polyvinylidene fluoride) resin as well as a preparation method and application thereof. The preparation method comprises the following steps: dissolving PVDF resin to be modified in a polar solvent to obtain a PVDF solution; the method comprises the following steps: adding weak organic alkali into a PVDF solution in a protective gas atmosphere, and then carrying out dehydrofluorination modification; and after the reaction is finished, terminating the reaction by using an acidic alcohol solution, and carrying out precipitation, washing and drying to obtain the light dehydrofluorination modified PVDF resin. Compared with the prior art, the high-temperature-resistant PVDF resin with high thermal stability and good melt processability can be obtained, and the high-temperature-resistant PVDF resin can be used for 200-DEG C-grade injection molding or extrusion molding products.

This invention discloses an anti-collapse agent for drilling fluids, its preparation method, and its application. The raw materials for the anti-collapse agent include melamine, formaldehyde aqueous solution, organophosphonate, dilute sulfuric acid, water, epichlorohydrin, and a solid acid catalyst. The preparation method of the anti-collapse agent is as follows: 1) Melamine, formaldehyde aqueous solution, and water are mixed evenly, and the pH value of the mixed solution is adjusted to 8-9. Then, the mixture is heated to react and obtain material flow A; 2) Dilute sulfuric acid is introduced into material flow A to react and obtain material flow B; 3) Organophosphonate, solid acid catalyst, and epichlorohydrin are added to material flow B. After the reaction is completed, the mixture is separated and dried to obtain the anti-collapse agent. The anti-collapse agent for drilling fluids provided by this invention has good high-temperature resistance, good salt resistance, temperature resistance, wall solidification, and filtration loss reduction performance. It can meet the requirements of water-based mud anti-collapse and wall solidification in complex well conditions such as deep wells and high-salt brine wells, and extend the safe construction period.

The application relates to the technical field of balloon catheters, in particular to a high-strength and durable balloon catheter for deep veins, which comprises a catheter and a connecting pipe, the inner wall of the catheter is movably connected with a communicating pipe, one side of the communicating pipe corresponding to the catheter is provided with an iron filament, the outer wall of the catheter is sequentially provided with a polytetrafluoroethylene layer, a toughness layer and a wear-resistant layer, one end of the catheter is fixedly connected with the connecting pipe, the outer wall of the connecting pipe is provided with a balloon main body, the upper end of the balloon main body is provided with a reinforcing layer and a thermoplastic polyurethane layer, the side close to the balloon main body of the connecting pipe is fixedly connected with a displacement section, the material of the balloon main body can be tightly combined with the thermoplastic polyurethane layer and the reinforcing layer, so that the balloon main body is not easy to fall off, the durability of the device is increased, the user can fold the catheter into a shape required by the human body, the use flexibility of the device is improved, the high-strength and durability of the device are increased, and the service life is prolonged.

The present application relates to a kind of high-temperature-resistant polymer foam material and its preparation method, belong to polymer processing technical field.The present application is by BMI resin (bismaleimide resin) and polyaryletherketone resin are compounded, after foaming, heat treatment is carried out, BMI resin is completed solidification, crosslinking structure is formed, to form semi-interpenetrating network, so, compared with the mechanical properties and heat resistance of polyaryletherketone foam of thermoplasticity, material can be obviously improved, in addition, the cold-pressing foaming mode used in the present application has the characteristics of short heat preservation time, foaming efficiency is high, can effectively control the solidification degree of BMI resin in foaming process, avoid BMI resin excessive crosslinking, so that composite material has good foaming performance.

The application discloses a cable processing device and a cable processing method, and relates to the technical field of cable processing, which comprises a closed control cabinet, supporting legs are fixedly installed at the four corners of the bottom of the closed control cabinet, a switch plate is arranged on the supporting legs, a handle is fixedly installed on the front side of the switch plate, and the closed control cabinet is characterized in that: inner ring plates are concentrically and rotatably installed at the two ends of an inlet and an outlet on the inner side of the closed control cabinet, and the two inner ring plates are fixedly connected through connecting rods. In the irradiation processing process, the multiple sets of centering rollers staggered and circumferentially distributed in cooperation with the irradiation lamps are in full contact with the outer surface of the cable, the cable is limited from multiple directions, and the cable is stably kept at the center position concentric with the inner ring plates, so that the problems of radial deviation, movement or swing of the cable in the continuous traction and conveying process are effectively avoided, the distance between the surface of the cable and the irradiation lamp is kept constant, the consistency of the irradiation dose and the processing stability are further improved, and the technical blank of the existing equipment without a synchronous centering mechanism is filled.

This invention relates to the field of concrete reinforcing fiber technology, and particularly to a bamboo powder-reinforced polypropylene composite fiber for concrete crack resistance and its preparation method. Through an integrated process of surface chemical modification (introducing bifunctional groups), melt grafting (forming chemical anchoring), and multi-stage stretching (forming a rough structure in situ), the strong interfacial bond between bamboo powder and polypropylene and the simultaneous construction of fiber surface functions are fundamentally achieved. This method not only solves the global problem of bamboo powder easily detaching from the polymer matrix, but also ensures good rheological properties of the melt due to the minimal damage to the polypropylene backbone caused by chemical grafting. This makes it possible to subsequently prepare fine denier fibers (with diameters as low as 30 μm) through high-ratio multi-stage stretching, overcoming the technical bottleneck of traditional modification methods that struggle to balance strong interfacial bonding and high spinnability.