5results about How to "Control degradation rate" patented technology

The invention relates to a biodegradable mulching film special material, a mulching film and a preparation method of the mulching film. Biodegradable materials such as PBAT, PLA and PBS are adopted, PBAT is used as a main material, and the cost is reduced through reasonable proportioning. Low-cost raw materials such as black master batches and talcum powder and additives such as a lubricant and an anti-hydrolysis agent are added, so that the cost is further reduced while the performance of the mulching film is ensured. The degradation speed of the mulching film can be controlled by adjusting the material ratio and is matched with the growth cycle of crops. The black mulching film has good heating and heat preservation effects and inhibits growth of weeds. The talcum powder, the antioxidant, the anti-ultraviolet agent and the like are added, so that the physical properties of the mulching film are improved, the water-retaining property, the tensile strength and the like are improved, PBAT is enhanced, and the production cost is reduced. The compatilizer improves the compatibility of the raw materials and improves the performance of the mulching film. And the nucleating agent improves the crystallization property of the mulching film, and improves the transparency, glossiness and impact resistance. On the whole, the performance of the mulching film is guaranteed, meanwhile, the cost is reduced, and the durability and the tear resistance are improved.

The present application provides a degradable vena cava filter with an expansion structure, which relates to the field of cardiovascular medical devices, and includes a stent segment, which includes a plurality of expansion components connected in sequence along the circumferential direction, each expansion component is provided with an anchor hook, and the anchor hook is embedded in the blood vessel wall for positioning the filter; when the plurality of expansion components are stretched, the plurality of expansion components expand outward in a direction away from the axis. By providing a plurality of expansion components, when the expansion components are stretched due to blood flow impact, the plurality of expansion components can respectively expand outward in the radial direction and drive the corresponding anchor hooks to expand outward, so that the stent segment fits more closely to the blood vessel wall, improves the anchoring ability of the anchor hook on the blood vessel wall, and reduces the displacement problem of the degradable vena cava filter with an expansion structure during use.

The invention discloses a degradable medicinal plastic bottle and a preparation method thereof. The mass ratio of polylactic acid, a biodegradable elastomer, a compound plasticizer, a nucleating agent and a photosensitizer in the degradable medicinal plastic bottle is 100: (15-20): (2-4): (2-4): (1-3); the biodegradable elastomer is obtained by mixing polyhydroxybutyrate, polycaprolactone, polybutylene succinate and the like in a weight ratio; the compound plasticizer is obtained by mixing a bio-based polycarboxylic acid plasticizer, a cellulose grafted polycaprolactone derivative, modified castor oil and acetyl tributyl citrate; the nucleating agent is one of a polylactic acid stereocomplex and TMC-200; and the photosensitizer is modified titanium dioxide, which effectively solves the problem that the plastic bottle in the prior art is insufficient in physical properties, photocatalytic efficiency and antibacterial properties.

The invention relates to the technical field of wastewater treatment, and specifically discloses a method for treating refractory organic wastewater. The method comprises the following steps: pumping wastewater into an anaerobic tank with a residence time of 0.5-2.0h; pumping effluent from the anaerobic tank into an anoxic tank with a residence time of 0.5-3.5h; pumping effluent from the anoxic tank into an aerobic tank with a residence time of 4-12.0h, and refluxing a mixed solution to an anoxic reaction tank with a reflux ratio of 100-500%; pumping effluent from the aerobic tank into a secondary sedimentation tank with a residence time of 1.0-4.0h; pumping precipitated effluent from the secondary sedimentation tank into an ozone ultrasonic reaction tank with a reaction time of 0.2-1.0h; pumping oxidized effluent into a pH adjustment tank to adjust the pH to 3.0-5.0; and pumping oxidized effluent into an ultraviolet oxidation tank for oxidation treatment. In this invention, part of the organic pollutants are removed through the anaerobic-anoxic-aerobic combined process, and then the purpose of harmless treatment is achieved through two treatment processes: ozone-ultrasound synergistic process and ultraviolet-persulfate-hydrogen peroxide composite process.

This invention relates to the field of medical device manufacturing technology, and in particular to a method for preparing a composite material stent and the stent made therefrom. The method includes the following steps: Step S1, preparation of magnesium alloy tubing and initial processing of the skeleton; Step S2, surface pretreatment of the skeleton; Step S3, construction of an intermediate bonding layer; Step S4, coating with a PLLA outer layer; Step S5, molding and post-processing; Step S6, final inspection and sterilization. This invention achieves synergistically enhanced mechanical properties. The magnesium alloy core provides strong initial support, while the PLLA outer layer provides supplementary support. It also exhibits controllable degradation performance; the PLLA outer layer effectively delays the corrosion of the magnesium alloy by chloride ions and other substances in body fluids, extending the support time. The PLLA outer layer isolates the magnesium alloy from direct contact with blood, further reducing the risk of thrombosis. The specially designed intermediate bonding layer structure ensures the structural integrity of the stent during its service life.