私密直播全婐app免费大渔直播,国产av成人无码免费视频,男女同房做爰全过程高潮,国产精品自产拍在线观看

Poly(p-phenylene-2,6-benzobisoxazole) (PBO) fibers display weak outdoor stability and reliability due to their poor UV resistance and chemically inert surface. In this work, calcia-doped ceria (Ce_0.8Ca_0.2O_1.8) nanoparticles was fabricated via chemical co-precipitation method, and the novel Ce_0.8Ca_0.2O_1.8/P(S-co-BCB-co-MMA) organic-inorganic hybrid coating was then designed and prepared for surface functionalization of PBO fibers (PBO@P-Ce_0.8Ca_0.2O_1.8). Organic-inorganic hybrid coating presents high surface roughness and excellent UV resistance. When the concentration of Ce_0.8Ca_0.2O_1.8 nanoparticles with the particle size of about 50 nm is 0.6 wt%, PBO@P-Ce_0.8Ca_0.2O_1.8-3 fibers (sample 4, 0.6 wt%) present the best interfacial bonding strength with modified bisphenol A cyanate (BADCy) resins, the single fiber pull-out strength between sample 4 and modified BADCy resins reaches the maximum value of 4.6 MPa, 48.4% higher than that of pristine PBO fibers (sample 0, 3.1 MPa). Meanwhile, the tensile strength of sample 4 after 288 hours UV aging is increased from 1.4 GPa (PBO fibers) to 4.1 GPa. Overall, functionalized PBO fibers in this work demonstrate higher surface activity, excellent UV resistance and improved interfacial bonding strength with modified BADCy resins, which provides a new idea for functionalizing the surface activity and UV resistance of high-performance polymer fibers.

聚對苯撐苯并二噁唑（PBO）纖維具有較差的耐紫外線性能和表面化學惰性。本研究通過化學共沉淀法制備氧化鈣摻雜氧化鈰（Ce_0.8Ca_0.2O_1.8） 納米顆粒，進而設計Ce_0.8Ca_0.2O_1.8/P(S-co-BCB-co-MMA)有機-無機雜化涂層用于改性PBO纖維（PBO@P-Ce_0.8Ca_0.2O_1.8）。結果表明，Ce_0.8Ca_0.2O_1.8納米顆粒的粒徑約為50 nm；PBO@P-Ce_0.8Ca_0.2O_1.8-3纖維（樣品4，0.6 wt%）與改性雙酚A氰酸酯（BADCy）樹脂具有最佳的界面粘結強度，其單絲拔出強度達到最大值（4.6 MPa），比純PBO纖維與改性BADCy樹脂的單絲拔出強度（3.1 MPa）高48.4%。同時，樣品 4在紫外老化288小時后的拉伸強度從1.4 GPa（純PBO纖維）增加到4.1 GPa。本研究獲得的改性PBO纖維具有更高的表面活性、優異的耐紫外線性能以及與改性 BADCy樹脂具有更佳的界面粘結強度，為PBO纖維的表面功能化改性和提高其耐紫外線性能提供了新思路。