We report a characterization of the acoustic sensitivity of microstructured polymer optical fiber interferometric sensors at ultrasonic frequencies from 100kHz to 10MHz. The use of wide-band ultrasonic fiber optic sensors in biomedical ultrasonic and optoacoustic applications is an open alternative to conventional piezoelectric transducers. These kind of sensors, made of biocompatible polymers,...

Dimethacrylates are known to have good photoreactivity, but their radical polymerization usually leads to irregular, highly cross-linked, and brittle polymer networks with broad thermal polymer phase transitions. Here, the synthesis of monoand difunctional β-allyl sulfones is described, and those substances are introduced as potent addition−fragmentation chain transfer (AFCT) reagents leading t...

This letter discusses the effect of bonding energy on the delamination resistance of laminate composites using a ductile interleaf. The mechanism and methods for interleaf toughening are reviewed and the improvement in delamination resistance discussed. The bonding energy between the ductile interleaf polymer and the fibers as well as between the ductile interleaf polymer and the brittle matrix...

Stimuli-sensitive hydrogels changing their volumes and shapes in response to various stimulations have potential applications in multiple fields. However, these hydrogels have not yet been commercialized due to some problems that need to be overcome. One of the most significant problems is that conventional stimuli-sensitive hydrogels are usually brittle. Here we prepare extremely stretchable t...

Deformation behavior of the composite “eggshell–polymer plomb” was examined under bending. Hen eggs were taken as a biological material for experiments. It shown that viscoelastic polymer coating does not change type deformation composite, given eggshell continued to be brittle despite its mechanical characteristics varying widely solid. Joint “polymer plomb–eggshell” never cracked bending and ...

We report a novel mode of quasi-static oscillatory crack propagation when a cutting tip of moderately large width is driven through a thin brittle polymer film (Roman [1] , Ghatak [2]). Experiments show that the amplitude and wavelength of the oscillatory crack paths scale linearly with the width of the cutting tip over a wide range of length scales but are independent of the width of the sheet...

Space debris population in low Earth orbit has been increasing constantly with the increase in spacecraft missions. Hypervelocity space debris impacts limit the functionality of polymeric outer surfaces and, in extreme cases, might cause a total loss of a spacecraft. In this work, the fracture of Kapton films by ultrahigh velocity impacts was studied. A laser-driven flyer ground simulation syst...

The deformation mechanism of pharmaceutical powders, used in formulating directly compressed matrix tablets, affects the characteristics of the formed tablets. Three polymers of different deformation mechanisms were tested for their impact on theophylline directly compressed tablets namely Kollidon SR (KL SR, plastic deformation), Ethylcellulose (EC, elastic deformation) and Carnauba wax (CW, b...