A series of semi-crystalline multi-block thermoplastic polyurethanes (TPU), containing poly(butylene adipate) (PBA), polycaprolactone (PCL) and their equimolar mixture (PBA/PCL) as a soft segment was synthesized. The changes in the physical-mechanical and thermal properties of the materials observed in the course of a 36-month storage at room temperature were related to the corresponding structural evolution. The latter was monitored using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXS) and mechanical tests (tensile strength test). The effects of the composition of the soft segment on the phase separation and crystallization of the soft segment were analyzed in detail. It was found that the melting temperature of the crystalline phase increases with storage time, which is associated with hindering of the phase separation of the hard and soft segments of the TPU samples as it was detected by FTIR.
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http://dx.doi.org/10.3390/ma16020818 | DOI Listing |
Nat Commun
January 2025
Laboratoire Sciences et Ingénierie de la Matiére Molle, ESPCI Paris, CNRS, PSL University, Paris, France.
Stretchable elastic materials with high strength, toughness, and good ionic conductivity are highly desirable for wearable devices and stretchable batteries. Unfortunately, limited success has been reported to attain all of these properties simultaneously. Here, we report a family of ionically conductive elastomers (ICEs) without compromise between mechanical properties (high stiffness, reversible elasticity, fracture resistance) and ionic conductivity, by introducing a multiple network elastomer (MNE) architecture into a low polymer.
View Article and Find Full Text PDFCureus
December 2024
Trauma and Acute Care Surgery, Prince Sultan Military Medical City, Riyadh, SAU.
Jejunal diverticulum perforation is a rare condition and presents diagnostic challenges. A 41-year-old male presented to the emergency room with a history of vague, generalized, and continuous abdominal pain for two days. He was vitally stable; however, the abdominal examination revealed a soft and distended abdomen with positive rebound tenderness.
View Article and Find Full Text PDFJ Biomech
January 2025
School of Exercise and Health, Shanghai University of Sport, Hengren Rd. 200, Yangpu District, Shanghai 200438, China. Electronic address:
This study aims to compare shank, rearfoot and forefoot coordination and its variability between runners with habitual rearfoot strike (RFS) and non-RFS (NRFS). 58 healthy males participated in this study (32 RFS, 26 NRFS). Coordination patterns and variability were assessed for the shank, rearfoot, and forefoot segments using a modified vector coding technique during running.
View Article and Find Full Text PDFMed Biol Eng Comput
January 2025
School of Medical Engineering, Department of Cardiology of The First Affiliated Hospital of Xinxiang Medical University, Xinxiang Medical University, Xinxiang, 453003, Henan, China.
The research aims to investigate the mechanical response of footfalls at different velocities to understand the mechanism of heel injury and provide a scientific basis for the prevention and treatment of heel fractures. A three-dimensional solid model of foot drop was constructed using anatomical structures segmented from medical CT scans, including bone, cartilage, ligaments, plantar fascia, and soft tissues, and the impact velocities of the foot were set to be 2 m/s, 4 m/s, 6 m/s, 8 m/s, and 10 m/s. Explicit kinetic analysis methods were used to investigate the mechanical response of the foot landing with different speeds to explore the damage mechanism of heel bone at different impact velocities.
View Article and Find Full Text PDFJ Oral Maxillofac Surg
December 2024
Clinical Professor Department of Oral and Maxillofacial Surgery and Orthodontics, Texas A&M University College of Dentistry, Dallas, TX; Private Practice Baylor University Medical Center, Dallas, TX.
Traditional surgical techniques for segmental maxillary surgery include a combination of interdental osteotomies with paramidline bony cuts while keeping the palatal soft tissue intact. Besides surgical complexity, segmental maxillary procedures have been associated with higher incidence of relapse and complications. We present our experience with specific hard- and soft-tissue modifications (midline bony osteotomy and reflection of palatal soft tissue with carefully designed incisions) which will allow surgeons to perform larger expansions with a low incidence of complications and decreased relapse.
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