Water and Oil Repellent Finishing of Textiles by UV Curing: Evaluation of the Influence of Scaled-Up Process Parameters
In this work, various textile fabrics were coated with silicone and fluorocarbon-based resins by photo-curing using ultraviolet irradiation. A great number of large fabric samples were impregnated by padding with commercial finishing agents and then irradiated in air with a high power, semi-industrial UV source. The add-on of various finishing agents was kept low to reduce the treatment cost. White and dyed samples of different textile composition were treated and evaluated in terms of conferred repellency, yellowing, or color changes. Most relevant process parameters were investigated, utilizing the thermal process normally adopted at industrial level as reference. The results were statistically evaluated by ANOVA using Minitab 16 software, in order to identify the most influential parameters and to evaluate the real possibility of replacing the thermal treatment with UV curing.
Synthesis of a novel perfluorinated acrylate copolymer containing hydroxyethyl sulfone as crosslinking group and its application on cotton fabrics
Abstract An acrylate monomer (2-[(2-hydroxyethyl) sulfonyl] ethyl acrylate) containing hydroxyethyl sulfone as crosslinking group was synthesized and a novel perfluorinated acrylate copolymer (NPAC) was prepared by emulsion polymerization. The average size of the emulsion particles was about 101 nm. NPAC was applied to cotton fabric by a pad–dry–cure process. The finished fabric showed excellent water and oil repellency rating and good washing durability without adding extra crosslinking agent. Some other physical performances of the finished fabrics were examined. The dry wrinkle recovery angle (WRA ( W  +  F )°) increased to 214°. The tearing and tensile strength retention and whiteness index (WI) of the finished fabric decreased to 70, 63, and 69.7%, respectively, compared with the untreated fabric.
LYAPUNOV-BASED TRANSFER BETWEEN ELLIPTIC KEPLERIAN ORBITS
We present a study of the transfer of satellites between elliptic Keplerian orbits using Lyapunov stability theory specific to this problem. The construction of Lyapunov functions is based on the fact that a non-degenerate Keplerian orbit is uniquely described by its angular momentum and Laplace (- Runge-Lenz) vectors. We suggest a Lyapunov function, which gives a feedback controller such that the target elliptic orbit becomes a locally asymptotically stable periodic orbit in the closed-loop dynamics. We show how to perform a global transfer between two arbitrary elliptic orbits based on the local transfer result. Finally, a second Lyapunov function is presented that works only for circular target orbits.