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Novel monomers in radical ring-opening polymerisation for biodegradable and pH responsive nanoparticles
2019, Folini, Jenny, Huang, Chao-Hung, Anderson, James C., Meier, Wolfgang P., Gaitzsch, Jens
Responsive and biodegradable nanoparticles are essential for functional drug delivery systems. We herein report the first pH sensitive polyester from radical ring-opening polymerisation of novel amine-bearing cyclic ketene acetals (CKAs). The CKAs were synthesised via an intermediate carbonate and the resulting polyesters showed a pKa around pH 6. Together with an initial application in biodegradable nanoparticles, they open the pathway for a new generation of functional polyesters.
The role of winding pattern on filament wound composite cylinders under radial compression
2020, Lisbôa, Tales V., Almeida Jr, José Humberto S., Dalibor, Ingo H., Spickenheuer, Axel, Marczak, Rogério J., Amico, Sandro C.
Filament wound (FW) structures present a geometric characteristic in their helical layers: the winding pattern. The pattern, however, is usually disregarded in conventional experimental or numerical approaches even though it can affect the behavior of FW structures, and most studies that account for the pattern are only theoretical. This study aims at deepening the understanding of pattern effects via a comprehensive experimental campaign focusing on composites cylinders under radial compression. Ten winding patterns were considered, from 1 to 10 units along the circumferential direction. Strength, stiffness, absorbed energy and failure mechanisms were evaluated. The results show that the pattern may have a strong influence on both maximum bearing load and absorbed energy, whereas stiffness is less affected.