Search results for "Polypropylene"
showing 10 items of 177 documents
A New Prosthetic Implant for Inguinal Hernia Repair: Its Features in a Porcine Experimental Model
2011
Even after more than 100 years of inguinal hernia repair, the rate of complications and recurrence remains unacceptably high. In the last decades, few effective advances in surgical technique and materials have been made. The authors see them as minor adjustments in the shape and materials of the prosthetic implants. Still, the underlying genesis of inguinal hernia remains undefined. Based upon this, it seems the surgical repair of inguinal protrusions cannot be based upon the pathogenesis because the etiology to date has not been addressed. Most hernia repairs are performed with some degree of point fixation (sutures/tacks) to stop the mesh from migrating and creating high recurrence rates…
Intraperitoneal coated polypropylene hernia meshes: the dark side of the moon.
2014
To date, the use of meshes in repairing abdominal wall defects has brought many advantages, especially in terms of recurrence prevention, but it is not exempt from complications, such as chronic pain, entero-cutaneous fistulas and intestinal obstruction. Here we report a case of intestinal obstruction in a patient with a large umbilical hernia treated laparoscopically by means of a composite polypropylene mesh, six year before.A 49-year-old man came to our care with a 3-day history of central and right lower abdominal quadrant pain and a clinical picture of intestinal obstruction. Six years before the patient underwent a laparoscopic intervention to repair his umbilical hernia, with the pos…
Laparoscopic Repair of Boundary Incisional Hernia in a Kidney Transplant Patient: A Safe Tacks-Fibrin Glue Combined Mesh Fixation Technique.
2018
Abstract Background Incisional hernia in renal transplant patients is a complication that negatively affects the global outcome of transplant and quality of life. The repair of this condition was classically made by open repair with mesh. Increasing evidence suggests that laparoscopic repair could be advocated as the technique of choice in these patients with optimal results. However, the fixation of mesh should be performed by a mixed combination of fibrin sealant (lateral margin of wall defect) and tacks (medial margin). The tacks fixation of the mesh along the lateral margin of the wall defect, close to the graft, is generally difficult for the small size of the remaining aponeurotic pla…
Enhanced angiogenesis in the 3D dynamic responsive implant for inguinal hernia repair ProFlor
2021
Biologic response to hernia prostheses represents a continuous source of debate. Conventional hernia meshes, in their typical static, passive configuration have been used for decades to reinforce the herniated abdominal wall. These flat implants, mainly fixated with sutures or tacks, induce poor quality fibrotic ingrowth that shrinks the mesh. In groin hernia repair, flat meshes are applied in the delicate inguinal surrounding where uncontrolled development of a scar plate can impair movement and may incorporate the sensitive nerves crossing this area. Complications deriving from mesh fixation and nerve entrapment are frequent and unpleasant for patients. To remedy these problems, a multila…
Rheological, mechanical and morphological characterization of monopolymer blends made by virgin and photo-oxidized polypropylene
2021
In this work, monopolymer blends of virgin polypropylene and photo-oxidized polypropylene were prepare and characterized. The polypropylene samples were subjected to accelerated ageing to simulate the effects of outdoor exposure of polypropylene. After exposure, samples were pelletized and mixed with the same virgin polymer. The rheological, mechanical and morphological characterization was conducted on both the polymers and the blends. Both viscosity and mechanical properties decrease with increases in the content of recycled, photo-oxidized components and of the level of degradation of this component. In addition, the experimental data were compared with a model that takes into account bo…
Copolymer−Cyclodextrin Inclusion Complexes in Water and in the Solid State. A Physico-Chemical Study
2008
The formation of inclusion complexes (ICs) composed of cyclodextrins (CDs) and poly(ethylene oxides)-poly(propylene oxides)-poly(ethylene oxides) (PEO-PPO-PEO) was studied. To this purpose, native and hydroxypropyl cyclodextrins with different cavity size were chosen. The PEO-PPO-PEO copolymers were selected to study the role of the molecular weight, keeping constant the hydrophilic/hydrophobic ratio, and the hydrophilicity. The volumetric studies at 25 degrees C allowed to determine the equilibrium constant and the volume change for the IC formation in water as well as the IC stoichiometry. Surface tension experiments evidenced that the copolymer and the CD interfacial behavior is controll…
Morphology, Rheological and Mechanical Properties of Isotropic and Anisotropic PP/rPET/GnP Nanocomposite Samples
2021
The effect of graphene nanoplatelets (GnPs) on the morphology, rheological, and mechanical properties of isotropic and anisotropic polypropylene (PP)/recycled polyethylene terephthalate (rPET)-based nanocomposite are reported. All the samples were prepared by melt mixing. PP/rPET and PP/rPET/GnP isotropic sheets were prepared by compression molding, whereas the anisotropic fibers were spun using a drawing module of a capillary viscometer. The results obtained showed that the viscosity of the blend is reduced by the presence of GnP due to the lubricating effect of the graphene platelets. However, the Cox–Merz rule is not respected. Compared to the PP/rPET blend, the GnP led to a slight incre…
Morphology, reorganization and stability of mesomorphic nanocrystals in isotactic polypropylene
2006
Abstract The morphology and thermodynamic stability of crystals of isotactic polypropylene (iPP) were analyzed as a function of the path of crystallization by atomic force microscopy (AFM) and differential scanning calorimetry (DSC). Samples were melt-crystallized at different rates of cooling using a “controlled rapid cooling technique”, and subsequently annealed at elevated temperature. Mesomorphic equi-axed domains with a size less than 20 nm were obtained by fast cooling from the melt at a rate larger about 100 K s−1. These domains stabilize on heating by growing in chain direction and cross-chain direction, to reach a maximum size of about 40–50 nm at a temperature of 433 K, with the q…
Effects of natural fibres reinforcement in lime plasters (kenaf and sisal vs. Polypropylene)
2014
Nowadays the tendency to realize environment-friendly products is becoming more widespread to ensure sustainable and smart development. The synthetic fibres, frequently used, are harmful to the environment because they are non-degradable and non-renewable. Their use has resulted in an increase of oil consumption. Therefore, the possibility of replacing them with natural fibres becomes increasingly concrete confirmed by the researches and investigations carried out. In this work three lime based plasters were prepared and analysed to evaluate the influence on their performance of different fibres used as reinforcement. In particular each plaster was realised by adding to the mortar the same …
Effect of a Compatibilizer on the Morphology and Properties of Polypropylene/Polyethylentherephthalate Spun Fibers
2017
Fibers spun by melt spinning of binary and ternary polypropylene/ polyethylenetherephthalate blends have been produced and characterized in order to investigate the effect of a compatibilizer on their morphology and mechanical properties. The compatibilizer was a maleic anhydride-functionalized rubber copolymer. The effect of the compatibilizer was well evident in the isotropic state, as the morphology became very fine, the size of the dispersed particles was very small, and the adhesion was better. The effect of the compatibilizer on the mechanical properties is very relevant, especially in the elongation at break. On the contrary, no relevant effect was observed in the anisotropic oriente…