Muro del Alcoy, Spain
Muro del Alcoy, Spain

Time filter

Source Type

Espana J.M.,Polytechnic University of Valencia | Fages E.,Textile Research Institute AITEX | Moriana R.,Textile Research Institute AITEX | Boronat T.,Polytechnic University of Valencia | Balart R.,Polytechnic University of Valencia
Polymer Composites | Year: 2012

The aim of this study is to establish the thermal performance of a biocomposite (Arbofill kokos®), stabilized with different natural phenolic additives, to check the antioxidant capacity of the resulting compounds. Different phenolic compounds (thymol, carvacrol, α-tocopherol, and tannic acid) were used as biobased additives and the concentrations ranged between 0.5 wt% and 2 wt%. The results obtained were compared with formulations containing a typical industrial petroleum-based antioxidant agent (octadecyl-3-(3,5-di-tert- butyl-4-hydroxyphenyl) propionate). Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to characterize the antioxidant performance of the selected natural additives. The antimicrobial effect of these natural phenolic compounds was also studied by analyzing the growth of bacterial colonies. The comparison between the natural phenolic compounds and the petroleum-based antioxidant compound showed good antioxidant action for natural phenolic compounds; in all the mixtures of biocomposite and antioxidant agent the oxidation onset temperature (OOT) increased in a remarkable way, but the highest stabilization effect was achieved with α-tocopherol with provides a % increase on OOT of about 45%. With regard to antibacterial activity of the different natural phenolic compounds, thymol, and carvacrol showed interesting antibacterial properties against Staphylococcus aureus. Copyright © 2012 Society of Plastics Engineers.

Ferrero B.,Textile Research Institute AITEX | Fombuena V.,Polytechnic University of Valencia | Fenollar O.,Polytechnic University of Valencia | Boronat T.,Polytechnic University of Valencia | Balart R.,Polytechnic University of Valencia
Polymer Composites | Year: 2015

In the present study the valorization of wastes from Posidonia oceanica (PO) has been carried out in order to obtain a fully biobased composite material in combination with a biobased polyethylene obtained from sugar cane as matrix. Morphological analysis by scanning electron microscopy (SEM) of the fractured surfaces from impact tests has revealed a homogenous distribution of particles of PO, as a consequence, good balanced properties have been obtained for composites with PO contents in the 5-40 wt%. Thermal properties of composites have been studied through differential scanning calorimetry (DSC) and thermogravymetric analysis (TGA); the obtained results show an improvement on the thermal degradation. With regard to thermomechanical properties, dynamic mechanical analysis (DMA) results have shown a much enhanced storage modulus (G′) as the Posidonia oceanica content increases. Tensile tests have shown a remarkable increase in stiffness with tensile modulus values about 60% higher for composites with 40 wt% with regard to unfilled material. In a similar way, the flexural modulus is more than twice with regard the unloaded polyethylene. Shore D hardness confirms this improvement on mechanical properties and Charpy impact test shows values very similar to sample without PO, so that the intrinsic high impact energy absorption of HDPE is maintained in HDPE-PO composites. The water uptake test determines that the water absorption percent does not exceed 8%, which is relatively low for a high immersion time (5 months), which guarantees a dimensional stability in lifetime for these composites. © 2014 Society of Plastics Engineers.

Samper M.D.,Polytechnic University of Valencia | Fages E.,Textile Research Institute AITEX | Fenollar O.,Polytechnic University of Valencia | Boronat T.,Polytechnic University of Valencia | Balart R.,Polytechnic University of Valencia
Journal of Applied Polymer Science | Year: 2013

This article presents a study on the stabilization of polypropylene against thermo-oxidation and UV radiation by using natural phenolic compounds derived from the structures of flavonoids: a flavone (chrysin), a flavanol (quercetin), two flavanone glycosides (hesperidin and naringin), and flavanoligand (silibinin). Thermal stabilization has been assessed in an oxidizing atmosphere by means of differential scanning calorimetry both in isothermal and in dynamic conditions. In addition, the effectiveness of these phenolic compounds as thermal stabilizers at high temperature has been quantified with the use of thermogravimetric analysis. Stabilization against UV radiation has been estimated by studying the morphology changes of the exposed surfaces by scanning electron microscope (SEM); also, surface chemical changes have been followed by infrared spectroscopy. Global results show that flavonoid compounds of type flavonols (quercetin and silibinin) provide the best results in stabilizing both against oxidation and against the action of UV radiation. © 2012 Wiley Periodicals, Inc.

Lopez R.,Polytechnic University of Valencia | Pascual M.,Polytechnic University of Valencia | Garcia-Sanoguera D.,Textile Research Institute AITEX | Sanchez-Nacher L.,Textile Research Institute AITEX | Balart R.,Textile Research Institute AITEX
Fibers and Polymers | Year: 2012

The use of nonwoven textile substrates for filtration and absorption purposes is generalized due to the high surface area they can provide. Many of these applications require good wetting properties to increase efficiency. In this work, low pressure plasma treatment with a CH4-O2 mixture gas has been used to increase surface wettability and subsequent absorption properties on nonwoven polypropylene substrates. CH4 plasma treatment leads to a plasma polymerization process which results in hydrophobic surface finishing, but in combination with O2, it is possible to form a functionalized plasmapolymerized layer thus improving wetting properties. Changes in wetting properties have been studied by contact angle measurements showing that optimum wetting properties are obtained with exposure times to plasma treatment of about 10 min, and no significant changes are obtained for longer exposure times. Absorption efficiency has been followed by determining three different parameters by the guidelines of the UNE-EN-ISO 9073-6 standard: wetting time, liquid absorption capacity (LAC) and liquid propagation rate or absorption speed. All these properties are remarkably improved as the exposure time to CH4-O2 plasma increases; this improvement is remarkably high for relatively short exposure times (5-10 min) and no significant changes are obtained for long exposure times so that, it is possible to conclude that previous plasma treatment with exposure times in the 5-10 min range is an efficient method to improve overall absorption properties of nonwoven polypropylene substrates. © 2012 The Korean Fiber Society and Springer Science+Business Media Dordrecht.

Pascual J.,Textile Research Institute AITEX | Fages E.,Textile Research Institute AITEX | Balart R.,Polytechnic University of Valencia | Fenollar O.,Polytechnic University of Valencia | Boronat T.,Polytechnic University of Valencia
AIP Conference Proceedings | Year: 2010

In the last years, a remarkable increase in the use of nanoparticles as fillers of polymer materials has been detected. It is mainly due to the excellent properties that these materials can provide when added to polymer matrices as a consequence of the high specific surface, so that, small additions can lead to a remarkable increase in overall properties. Small additions of carbon nanotubes (CNTs) in a polypropylene matrix promote an increase in mechanical and thermal performance. Presence of CNTs leads to formation of interlock points with polypropylene chains and this has a positive effect on mechanical properties; thus an increase in elastic modulus and tensile strength are obtained for relatively small amounts of CNTs in the 1-3 wt. %. Regarding thermal properties, it is important to note that a remarkable increase of thermal stability is detected at medium temperatures (oxidation onset measured by differential scanning calorymetry) and high temperatures (degradation measured by thermogravymetric analysis). So, we can conclude that the use of small additions of CNTs is a useful technique to improve polypropylene performance from both technical and economical point of view since good balanced properties are obtained. Furthermore, the cost of these nanoparticles has decreased considerably in the last years and. © 2010 American Institute of Physics.

Lopeza R.,Textile Research Institute AITEX | Boronatb T.,Polytechnic University of Valencia | Pascuala M.,Textile Research Institute AITEX | Calvoa O.,Textile Research Institute AITEX | Balartb R.,Polytechnic University of Valencia
AIP Conference Proceedings | Year: 2010

In this work we have used low-pressure plasma with a gas based on methane and oxygen mixture to improve wettability and durability of a PP nonwoven fabrics. The obtained results show good durability with the use of methaneoxygen plasma mixture gas. The effects of the plasma are similar to a plasmapolymerization process but in this case we obtain hydrophilic properties with high durability. The surface does not suffer important changes and the roughness of the material remains constant. © 2010 American Institute of Physics.

Carbonell A.,Polytechnic University of Valencia | Boronat T.,Polytechnic University of Valencia | Fages E.,Textile Research Institute AITEX | Girones S.,Textile Research Institute AITEX | And 4 more authors.
Materials and Design | Year: 2015

Biobased composites were fabricated with waste of tiger nut natural fibers, different binder fibers (lyocell and cotton) and thermo-bonding fibers (PLA, HDPE, PA6-CoPA). These composites were processed by wet-laid process and hot-press molding process. The obtained composites were characterized by flexural, hardness and Charpy impact tests.The internal structure of the composite was analyzed by SEM observing a significant heterogeneity. The high fiber content (80. wt.%) and the lack of a continuous matrix phase cause mediocre mechanical response of the material. Thermo-bonding fibers are more influential than the binder fibers. The best mechanical responses were obtained with additions of PLA fibers and thermo-bonding fibers. Flexural modulus was maximum (865. MPa) for 80. wt.% tiger nut/10. wt.% binder fiber/10% PLA fiber composite. © 2015 Elsevier Ltd.

Blanes M.,Textile Research Institute AITEX | Gisbert M.J.,Textile Research Institute AITEX | Marco B.,Textile Research Institute AITEX | Bonet M.,Polytechnic University of Valencia | And 2 more authors.
Textile Research Journal | Year: 2010

The influence of solution composition is directly related to the properties of polyvinyl alcohol (PVA) nanofibers. Electrospinning is a viable technique to develop PVA nanofibers. The presence of a crosslinking agent such as glyoxal can produce variations not only in anti-water solubility effect, but also in the morphology of the electrodeposited fibers. The objective of this study was to characterize the influence of glyoxal on PVA nanofibers. Thus, we studied fiber dimensions, the weight of deposited fibers, and fiber crystallinity. The relation between those properties and the properties of the nanofiber web (color, opacity, and roughness) were studied. In this study we changed glyoxal concentration. Scanning electron microscopy, differential scanning calorimetry, and atomic force microscopy showed changes in the fiber properties. We could observe how the diameter fiber increased, the collector surface was widely covered, and the fiber crystallinity decreased. Regarding the properties of the web, the roughness decreased and the color turned whiter. © The Author(s), 2010.

Loading Textile Research Institute AITEX collaborators
Loading Textile Research Institute AITEX collaborators