Publications by authors named "Juanzi Li"
Article Synopsis
- A low-viscosity epoxy resin called TFEPA, compatible with liquid oxygen, was developed to reduce the viscosity of phosphorus-containing bisphenol F epoxy resins, making them easier to process at higher temperatures.
- The viscosity of the bisphenol F resin significantly decreased from 4925 to 749 mPa·s at 45 °C when mixed with 10 wt.% TFEPA, improving processing efficiency by increasing temperature and time windows by 73% and 186%.
- After curing, the composite maintained good properties at -196 °C, showing high tensile strength and toughness, with notable increases in flexural strength and strain energy, thanks to the addition of TFEPA.
To select the appropriate polymer thin films for liquid oxygen composite hoses, the liquid oxygen compatibility and the cryogenic mechanical properties of four fluoropolymer films (PCTFE, ETFE, FEP and PFA) and two non-fluoropolymer films (PET and PI) before and after immersion in liquid oxygen for an extended time were investigated. The results indicated that the four fluoropolymers were compatible with liquid oxygen before and after immersion for 60 days, and the two non-fluoropolymers were not compatible with liquid oxygen. In addition, the cryogenic mechanical properties of these polymer films underwent changes with the immersion time, and the changes in the non-fluoropolymer films were more pronounced.
View Article and Find Full Text PDFRecently, the application of polymer-based composites at cryogenic conditions has become a hot topic, especially in aerospace fields. At cryogenic temperature, the polymer becomes more brittle, and the adverse effect of thermal stress induced by temperature is more remarkable. In this paper, the research development of thermoset and thermoplastic polymers for cryogenic applications are all reviewed.
View Article and Find Full Text PDFArticle Synopsis
- The study examined how different reinforcement structures and hybrid materials affect the inter-laminar shear strength (ILSS) of carbon-glass hybrid fiber/bismaleimide composites when exposed to thermo-oxidative aging.
- The aging process caused deterioration in the resin and the bond between fibers and matrix, leading to reduced ILSS in the composites.
- Three-dimensional orthogonal woven hybrid composites maintained a higher ILSS retention compared to laminated composites, as they experienced no delamination thanks to Z-binder yarns that better supported shear loads, while those with carbon fiber layers exhibited better bonding performance than those with glass fiber.