The combination of natural rubber(NR)with epoxidized natural rubber(ENR)could improve the wet slid resistance,mechanical properties,abrasion resistance and thermo-oxidative aging resistance of NR,which showed importan...The combination of natural rubber(NR)with epoxidized natural rubber(ENR)could improve the wet slid resistance,mechanical properties,abrasion resistance and thermo-oxidative aging resistance of NR,which showed important research significance.Aramid nanofiber,as a new nano filler for polymer developed in recent years,had the advantages of both macroscopic fibers and polymer nanomaterials.The NR/ENR composites were prepared by dry mixing with NR and the pre-composite prepared from ENR latex and the modified aramid nanofibers(t-ANF).展开更多
Nanosized copper powders were prepared by a gel-casting method using copper nitrate, acrylamide（AM） and N, N′-methylenebisacrylamide（MBAM） as the main raw materials. The as-prepared copper powders were characteri...Nanosized copper powders were prepared by a gel-casting method using copper nitrate, acrylamide（AM） and N, N′-methylenebisacrylamide（MBAM） as the main raw materials. The as-prepared copper powders were characterized by X-ray diffractometry and scanning electron microscopy, and then added into a 48# industrial white oil. Dispersion and wear properties of the compounded lubricating oil were tested. The results show that the copper powders prepared are of high purity, fine dispersibility with mean particle size of about 60 nm and with a narrow particle size distribution. The nanosized copper powders can be well dispersed in the lubricating oil. The addition of the copper powders obviously improves the anti-wear properties of the lubricating oil owing to their good self-repairing performance. Compared with 48# industrial white lubricating oil, the friction coefficient of GCr15 steel with the compounded oil containing 0.6% copper powders reduces by 0.07 and nearly no wear chippings are found in the scratches of the friction counter parts.展开更多
Purpose： To develop a novel injectable strontium-containing calcium phosphate cement with collagen. Methods： A novel calcium phosphate bone cement （CPC） was prepared with the addition of strontium element, collage...Purpose： To develop a novel injectable strontium-containing calcium phosphate cement with collagen. Methods： A novel calcium phosphate bone cement （CPC） was prepared with the addition of strontium element, collagenl, and modified starch; the injectability, solidification time, microstructure, phase composition, compressive strength, anti-collapsibility and histological properties of material were evaluated. Results： The results showed that the material could be injected with an excellent performance; the modified starch significantly improved the anti-washout property of cement; with the liquid to solid ratio of 0.3, the largest compressive strength of cement was obtained （48.0 MPa _＋ 2.3 MPa）; histological examination of repair tissue showed that the bone was repaired after 16 weeks; the degradation of cement was consistent with the new bone growth. Conclusion： A novel injectable collagen-strontium-containing CPC with excellent compressive strength and suitable setting time was prepared, with addition of modified starch. The CPC showed a good anti-washout property and the degradation time of the cement met with the new bone growing. This material is supposed to be used in orthopedic and maxillofacial surgery for bone defects.展开更多
文摘The combination of natural rubber(NR)with epoxidized natural rubber(ENR)could improve the wet slid resistance,mechanical properties,abrasion resistance and thermo-oxidative aging resistance of NR,which showed important research significance.Aramid nanofiber,as a new nano filler for polymer developed in recent years,had the advantages of both macroscopic fibers and polymer nanomaterials.The NR/ENR composites were prepared by dry mixing with NR and the pre-composite prepared from ENR latex and the modified aramid nanofibers(t-ANF).
基金Project(51674095)supported by the National Natural Science Foundation of China
文摘Nanosized copper powders were prepared by a gel-casting method using copper nitrate, acrylamide（AM） and N, N′-methylenebisacrylamide（MBAM） as the main raw materials. The as-prepared copper powders were characterized by X-ray diffractometry and scanning electron microscopy, and then added into a 48# industrial white oil. Dispersion and wear properties of the compounded lubricating oil were tested. The results show that the copper powders prepared are of high purity, fine dispersibility with mean particle size of about 60 nm and with a narrow particle size distribution. The nanosized copper powders can be well dispersed in the lubricating oil. The addition of the copper powders obviously improves the anti-wear properties of the lubricating oil owing to their good self-repairing performance. Compared with 48# industrial white lubricating oil, the friction coefficient of GCr15 steel with the compounded oil containing 0.6% copper powders reduces by 0.07 and nearly no wear chippings are found in the scratches of the friction counter parts.
文摘Purpose： To develop a novel injectable strontium-containing calcium phosphate cement with collagen. Methods： A novel calcium phosphate bone cement （CPC） was prepared with the addition of strontium element, collagenl, and modified starch; the injectability, solidification time, microstructure, phase composition, compressive strength, anti-collapsibility and histological properties of material were evaluated. Results： The results showed that the material could be injected with an excellent performance; the modified starch significantly improved the anti-washout property of cement; with the liquid to solid ratio of 0.3, the largest compressive strength of cement was obtained （48.0 MPa _＋ 2.3 MPa）; histological examination of repair tissue showed that the bone was repaired after 16 weeks; the degradation of cement was consistent with the new bone growth. Conclusion： A novel injectable collagen-strontium-containing CPC with excellent compressive strength and suitable setting time was prepared, with addition of modified starch. The CPC showed a good anti-washout property and the degradation time of the cement met with the new bone growing. This material is supposed to be used in orthopedic and maxillofacial surgery for bone defects.
