PVDF was prepared by compression molding, and its phase content/structure assessed WAXD, DSC, FTIR-ATR spectroscopy. Next, samples were aged in bioethanol fuel at 60 °C or annealed the same temperature 30 ─ 180 days. Then, influence of aging/annealing on thermal stability, degradation kinetics, lifetime investigated thermogravimetric analysis (TGA/DTG), as well structure again examined. The crystallinity ~41% (from WAXD) ~49% DSC) identified for unaged PVDF, without significant changes after...

Porous scaffolds are biocompatible and bioactive temporary substrates. They should present appropriated microstructure, mechanical properties surface for guiding bone tissue regeneration. In this work, of Poly(3-hydroxybutyrate) (PHB) were printed by Selective Laser Sintering (SLS). The effect scan spacing (SS) powder layer thickness (PLT) on the morphology, dimensional deviations related to digital model sintered was evaluated. Curling observed in first built layers scaffolds, mainly with...

Polyamide 11 (PA11) is subjected to both a chemical and temperature gradient while it used in flexible pipes for oil prospecting. Due contact with fluid the inner part of polymer, expected that this will influence properties recycled material made PA11 after decommissioning. To investigate whether influences how aged affect recycling process, two types (one considering only other opposite part) were investigated using (XPS), thermal (DSC, TGA, MFI), mechanical analyses. Our results indicate...

Abstract Summary: Poly(3‐hydroxybutyrate) (PHB) 3D porous cubes were successfully built with Selective Laser Sintering (SLS), one of the many existing printing technologies. The resulting presented shape and dimensions very close to corresponding virtual model. Moreover, they resistant handling without presenting any visible damage. PHB powder did not present variation in thermal properties chemical composition after 32.15 hours SLS process as observed by proton nuclear resonance ( 1 H NMR)...

Abstract Polyhydroxybutyrate (PHB) is a thermoplastic, biodegradable, linear, and semicrystalline polyester synthesized by bacteria; while coir dust, waste generated during the coconut fiber processing, mixture of short fibers powder. The aim this work was to prepare characterize composites based on biopolymer biowaste, so that products were derived from natural renewable resources. produced compression molding. Composite properties evaluated scanning electron microscopy, low field nuclear...

Dynamic mechanical analysis (DMA) is one of the most common methods employed to study materials' composition and properties. However, complex modulus estimates provided by DMA are well-known show divergences between samples loading clamps. Few works in literature explore these do not address mathematical formulation comparative data different operational modes machines. Aiming at contributing fill this gap, work presents an investigation on for determined technique how it evaluated three...

Abstract Guided tissue regeneration is a technique used for periodontium reconstruction. This uses barrier membranes, which prevent epithelial growth in the wound site and may also be to release antibiotics, protect against opportunistic infections. Periodontal poly(3‐hydroxybutyrate) membranes containing metronidazole (a drug help infection control) were produced characterized. The kinetic mechanism of delivery leached nonleached membrane as well its cytotoxicity structural integrity...

Abstract Polyamide 11 (PA11) is a polymer used in flexible lines for oil prospection due to its properties. After the decommissioning of lines, materials are discarded landfills or left ocean. As developing sustainable economy utmost importance, reusing these would be step right direction. This research focused on examining two kinds PA11 previously see their properties changed compared virgin and infer if they can still reused. Chemical, thermal, mechanical analysis were employed analyze...

Abstract The preparation of 3D scaffolds using poly(3‐hydroxybutyrate) (PHB) and chitosan (CTS) has been proposed because the favorable interactions these materials with mammalian cells in particular osteoblasts (HOB). In this work, a new method producing porous based on swelling dense matrix PHB CTS was developed. Scanning electron microscopy images showed formation an interconnected structure inside structure. pore attributed to CTS. presented 70% porosity, heterogeneous pore‐size...

To evaluate the friction force in sliding systems composed of coated NiTi archwires, subjected to thermal cycling, and acid solution immersion, compare them polymeric wires. The null hypothesis is that there will be no difference among wires as force.Samples (n = 05), 15), OPTIS 05) 0.016 inches diameter 50 mm long, conjunction with Metafasix ligatures saliva InVu brackets, were submitted testing. Among 15 samples, 5 cycling for 3000 cycles; other samples immersed 30 days. results...

In recent years, there has been an increasing interest in repairing offshore steel structures by using adhesively joined carbon fiber reinforced polymers (CFRP). For such procedure, surface preparation plays a vital role to maintain the integrity of joint and ensure proper load transfer. The primary used oil gas industry is grit blasting due its known quality. However, logistic required major drawback limiting use repairs. Other procedures available are unable promote treatment. this paper,...

The distribution of light intensity three light-curing units (LCUs) to cure the resin-based composite for dental fillings was analyzed, and a homogeneity index [flat-top factor (FTF)] calculated. is based on M2 index, which used laser beams. An optical spectrum analyzer with an fiber produce x-y power profile each LCU guide. FTF-calculated values were 0.51 LCU1 0.55 LCU2, best FTF, although it still differed greatly from perfect FTF=1, 0.27 LCU3, poorest value even lower than Gaussian...

Special polymers have been used in the manufacture of storage structures and pipelines avoiding corrosive processes during ethanol fuel transport/storage. Therefore, this work investigated comparatively effects on physical-mechanical properties poly (ether ether ketone) (PEEK) polyamide 11 (PA-11) based ageing tests. The WAXD DSC results demonstrated slight reductions crystallinity degree aged PEEK, contrariwise to what happened with PA-11, where Xcincreased after ageing. However, thermal,...

Abstract As the polyamide 11 (PA11) present in flexible pipes for oil prospection is used, it also reacts with fluid components so that not only morphology of polymer changes but its properties. To see extent these chemical modifications and how they changed original material, different techniques were employed, such as ATR-FTIR, DSC, TGA, Melt-flow index (MFI), while sample was cut half to measure if direct contact had a huge influence. The results indicate degree PA11 part higher,...

Poly(vinylidene fluoride) was relaxed at different temperatures (23, 80 and 120 °C) strains (3.5, 7 10%) during 24 h. The material, as processed all conditions, characterized by tensile tests time-domain nuclear magnetic resonance (TD-NMR). Tensile after stress relaxation showed a huge drop in the elastic modulus, varying from 30% to 45% compared material. TD-NMR technique allowed correlate variation of mechanical property with evolution structure inside namely, decrease crystalline fraction...