Octavio Fenollar - Academia.edu (original) (raw)
Papers by Octavio Fenollar
XXVII Congreso Universitario de Innovación Educativa en las Enseñanzas Técnicas: Alcoy 17-19 de Junio de 2019 : actas, 2019, ISBN 978-84-09-02970-9, págs. 449-456, 2019
Most industrial polymers and composites have low surface free energy and lack of polar functional... more Most industrial polymers and composites have low surface free energy and lack of polar functional groups on their surface, resulting in a class of materials with poor adhesion properties. Currently used chemical or physical processes that have a number of drawbacks as they use products which harm the environment. An alternative to these processes are the treatments using plasma technologies. The equipment of plasma was situated in a stand, making it possible to modify the distance between sample and nozzle. In addition is possible to vary the feed speed of the sample with an adjustable speed drive. Therefore are analyzed the chemical and physical processes that occur on the surface of polyethylene that increase its adhesive properties changing the feed speed and distance between sample and nozzle. The adhesive properties were evaluated by peeling tests. The results show that at low speeds and distances the polar molecules are grafted in the surface of polyethylene giving a higher su...
Increased environmental awareness is driving the continuous search for new eco-friendly materials... more Increased environmental awareness is driving the continuous search for new eco-friendly materials. Within the category of Wood Plastics Composites (WPC), a new "Green Composite" is proposed, whose matrix is a bio-polyethylene (bioPE) obtained from sugar cane and whose load, with reinforcing properties due to its fibrous structure, is Thyme, as a residue from the distillation of a liquor manufactured in a local company. Load concentrations of 10%, 30% and 50% %w have been studied. Since the polymers are processed in the molten state and the loads influence their visco-elastic behavior, it is necessary to know the rheological behavior of these new compounds, in order to evaluate their processability. The melt polymer viscosity is very sensitive to the temperature and the shear rate at which it is being processed. The Cross-WLF model, based on the experimental results obtained with a capillary rheometer, describes the rheological behavior of the materials, thus enabling the d...
Polymers, 2021
This research reports the manufacturing and characterization of green composites made from recycl... more This research reports the manufacturing and characterization of green composites made from recycled polypropylene obtained from the remnants of polypropylene non-woven fabrics used in the textile industry and further reinforced with short hemp fibers (SHFs). To improve the interaction of the reinforcing fibers with the recycled polymeric matrix, two types of compatibilizing agents (maleic anhydride grafted, PP-g-MA, and maleinized linseed oil, MLO) were added during melt-processing, the percentage of which had to remain constant concerning the amount of fiber loading to ensure complete reactivity. Standardized test specimens were obtained by injection molding. The composites were characterized by mechanical (tensile, impact, and hardness), thermal (DSC, TGA), thermomechanical, FTIR, and FESEM microscopy tests. In addition, color and water uptake properties were also analyzed. The results show that the addition of PP-g-MA to rPP was satisfactory, thus improving the fiber-matrix inter...
Rapid Prototyping Journal, 2020
Purpose This paper aims to describe the influence of maleinized linseed oil (MLO), when used as a... more Purpose This paper aims to describe the influence of maleinized linseed oil (MLO), when used as a lubricant, on the thermal and rheological properties of PLA/MWCNTs (polylactic acid/multi-walled carbon nanotubes) and PLA/HNT (halloysite nanotubes) nanocomposites, as a reference for application in 3D printing processes. Design/methodology/approach Nanocomposites were obtained by melting in a twin-screw extruder, mixing PLA with MWCNTs and HNTs in different percentages of 0.5, 0.75 and 1 Wt.% for subsequent mixing by the same process with 5 phr MLO, for application in additive manufacturing, as analyzed by means of differential scanning calorimetry (DSC), capillary rheometry, melt flow rate (MFL) and field emission scanning electron microscopy (FESEM). Findings The results obtained for thermal characterization by using DSC indicate the non-variation of glass transition temperature Tg = 62 ± 2°C and a melting temperature (Tm) around 170°C. Crystallization temperature dropped by approxi...
Polymers, 2019
This research work aims to study the influence of the reprocessing cycles on the mechanical, ther... more This research work aims to study the influence of the reprocessing cycles on the mechanical, thermal, and thermomechanical properties of polylactide (PLA). To this end, PLA was subjected to as many as six extrusion cycles and the resultant pellets were shaped into pieces by injection molding. Mechanical characterization revealed that the PLA pieces presented relatively similar properties up to the third reprocessing cycle, whereas further cycles induced an intense reduction in ductility and toughness. The effect of the reprocessing cycles was also studied by the changes in the melt fluidity, which showed a significant increase after four reprocessing cycles. An increase in the bio-polyester chain mobility was also attained with the number of the reprocessing cycles that subsequently favored an increase in crystallinity of PLA. A visual inspection indicated that PLA developed certain yellowing and the pieces also became less transparent with the increasing number of reprocessing cycl...
Polymer International, 2019
The cover image is based on the Research Article Effect of different compatibilizers on environme... more The cover image is based on the Research Article Effect of different compatibilizers on environmentally friendly composites from poly(lactic acid) and diatomaceous earth by Angel Aguero et al. DOI: 10.1002/pi.5779. image
Journal of Polymers and the Environment, 2019
European Polymer Journal, 2018
The present study describes the effect of maleinized hemp seed oil (MHO) on the physical performa... more The present study describes the effect of maleinized hemp seed oil (MHO) on the physical performance of polylactide (PLA) pieces. To this end, PLA pieces with varying MHO contents in the 0-10 wt% range were manufactured by twin-screw extrusion (TSE) followed by injection molding. The resultant pieces were characterized in terms of their mechanical, thermal, and thermomechanical properties. The obtained properties suggested that, unlike typical plasticizers, MHO does not only induce an increment in elongation at break and impact strength but it also enhances both elastic modulus and tensile strength. In addition, it was observed a moderate decrease in the glass transition temperature (Tg). This was ascribed to a linear chain extension and/or branching phenomenon due to the reaction of the multiple maleic anhydride (MAH) groups present in MHO with the hydroxyl groups of the PLA terminal chains. Furthermore, morphology characterization revealed that, though certain phase separation occurred at its highest content, MHO was finely dispersed as submicron droplets within the PLA matrix contributing to improving toughness. The use of multi-functionalized reactive oils thus represents a highly sustainable solution to reduce the intrinsic brittleness of PLA materials without compromising their mechanical resistance and the toughened biopolymer pieces described herein can find interesting applications in, for instance, rigid packaging.
Polymer International, 2017
The use of maleinized linseed oil (MLO) as a potential biobased plasticizer for poly(lactic acid)... more The use of maleinized linseed oil (MLO) as a potential biobased plasticizer for poly(lactic acid) (PLA) industrial formulations with improved toughness was evaluated. MLO content varied in the range 0–20 phr (parts by weight of MLO per hundred parts by weight of PLA). Mechanical, thermal and morphological characterizations were used to assess the potential of MLO as an environmentally friendly plasticizer for PLA formulations. Dynamic mechanical thermal analysis and differential scanning calorimetry revealed a noticeable decrease in the glass transition temperature of about 6.5 °C compared to neat PLA. In addition, the cold crystallization process was favoured with MLO content due to the increased chain mobility that the plasticizer provides. PLA toughness was markedly improved in formulations with 5 phr MLO, while maximum elongation at break was obtained for PLA formulations plasticized with MLO content in the range 15–20 phr. Scanning electron microscopy revealed evidence of plast...
Materials & Design, 2016
Renewable vinyl plastisol composites based on epoxidized linseed oil (ELO) were developed by intr... more Renewable vinyl plastisol composites based on epoxidized linseed oil (ELO) were developed by introducing reed wood flour • Optimal materials were observed for vinyl plastisol composites containing 20 to 30 wt.-% of wood flour particles of 500 μm • Wood flour was exposed to ultraviolet (UV) radiation to increase its interfacial adhesion with the vinyl plastisol • Ductility of the vinyl plastisol composites prepared with UV-exposed wood flour for 4 min increased up to 3.5 times.
Polymer International, 2016
In this work, binary blends based on poly(lactic acid)-PLA and poly(caprolactone)-PCL were prepar... more In this work, binary blends based on poly(lactic acid)-PLA and poly(caprolactone)-PCL were prepared by melt mixing in a twin screw co-rotating extruder in order to increase the low intrinsic elongation at break of PLA for packaging applications. Although PLA and PCL show low miscibility, presence of PCL leads to a remarkable increase in ductile properties of PLA. Different mechanical properties were evaluated in terms of PCL content up to 30 weight % PCL. Additionally to tensile and flexural properties, the Poisson's ratio was obtained by using bi-axial extensometry to evaluate transversal deformations when axial loads are applied. Very slight changes in the melt temperature (T m) and glass transition temperature (T g) of PLA were observed thus indicating low miscibility of the PLA-PCL system. Field emission scanning electron microscopy (FESEM) revealed some interactions between the two components of the blend since the morphology is characterized by non-spherical poly(caprolactone) drops dispersed into the PLA matrix. In addition to the improvement of mechanical ductile properties, PCL provides higher degradation rates of blends under conditions of composting for contents below 22.5% PCL.
Composites Part B: Engineering, 2016
Different amounts of epoxidized linseed oil (ELO) have been added to poly(lactic acid)-PLA compos... more Different amounts of epoxidized linseed oil (ELO) have been added to poly(lactic acid)-PLA composites with hazelnut shell flour (HSF) to provide a plasticizing effect and improve the low intrinsic ductile properties of PLA/HSF composites. Mechanical, thermal, thermo-mechanical and dynamic mechanical properties have been studied in terms of the weight percentage ELO. Mechanical resistant properties in both tensile and flexural tests decrease with wt.% ELO while a remarkable increase with wt.% ELO is obtained. These results reveal a clear plasticization effect of ELO but, in addition, internal structure of PLA/HSF/ELO composites shows good PLA-HSF (matrix-particle) interactions so that indicating that ELO also provides a coupling effect between PLA matrix and HSF filler. ELO addition leads to a decrease in storage modulus (G') obtained by dynamic mechanical thermal analysis (DMTA) in torsion mode thus giving clear evidence of the plasticization effect of ELO. Overall, the use of ELO in PLA/HSF composites is an attracting way to improve the low intrinsic fragility of these green
Polymer Composites, 2014
In the present study the valorization of wastes from Posidonia oceanica (PO) has been carried out... more 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...
XXVII Congreso Universitario de Innovación Educativa en las Enseñanzas Técnicas: Alcoy 17-19 de Junio de 2019 : actas, 2019, ISBN 978-84-09-02970-9, págs. 449-456, 2019
Most industrial polymers and composites have low surface free energy and lack of polar functional... more Most industrial polymers and composites have low surface free energy and lack of polar functional groups on their surface, resulting in a class of materials with poor adhesion properties. Currently used chemical or physical processes that have a number of drawbacks as they use products which harm the environment. An alternative to these processes are the treatments using plasma technologies. The equipment of plasma was situated in a stand, making it possible to modify the distance between sample and nozzle. In addition is possible to vary the feed speed of the sample with an adjustable speed drive. Therefore are analyzed the chemical and physical processes that occur on the surface of polyethylene that increase its adhesive properties changing the feed speed and distance between sample and nozzle. The adhesive properties were evaluated by peeling tests. The results show that at low speeds and distances the polar molecules are grafted in the surface of polyethylene giving a higher su...
Increased environmental awareness is driving the continuous search for new eco-friendly materials... more Increased environmental awareness is driving the continuous search for new eco-friendly materials. Within the category of Wood Plastics Composites (WPC), a new "Green Composite" is proposed, whose matrix is a bio-polyethylene (bioPE) obtained from sugar cane and whose load, with reinforcing properties due to its fibrous structure, is Thyme, as a residue from the distillation of a liquor manufactured in a local company. Load concentrations of 10%, 30% and 50% %w have been studied. Since the polymers are processed in the molten state and the loads influence their visco-elastic behavior, it is necessary to know the rheological behavior of these new compounds, in order to evaluate their processability. The melt polymer viscosity is very sensitive to the temperature and the shear rate at which it is being processed. The Cross-WLF model, based on the experimental results obtained with a capillary rheometer, describes the rheological behavior of the materials, thus enabling the d...
Polymers, 2021
This research reports the manufacturing and characterization of green composites made from recycl... more This research reports the manufacturing and characterization of green composites made from recycled polypropylene obtained from the remnants of polypropylene non-woven fabrics used in the textile industry and further reinforced with short hemp fibers (SHFs). To improve the interaction of the reinforcing fibers with the recycled polymeric matrix, two types of compatibilizing agents (maleic anhydride grafted, PP-g-MA, and maleinized linseed oil, MLO) were added during melt-processing, the percentage of which had to remain constant concerning the amount of fiber loading to ensure complete reactivity. Standardized test specimens were obtained by injection molding. The composites were characterized by mechanical (tensile, impact, and hardness), thermal (DSC, TGA), thermomechanical, FTIR, and FESEM microscopy tests. In addition, color and water uptake properties were also analyzed. The results show that the addition of PP-g-MA to rPP was satisfactory, thus improving the fiber-matrix inter...
Rapid Prototyping Journal, 2020
Purpose This paper aims to describe the influence of maleinized linseed oil (MLO), when used as a... more Purpose This paper aims to describe the influence of maleinized linseed oil (MLO), when used as a lubricant, on the thermal and rheological properties of PLA/MWCNTs (polylactic acid/multi-walled carbon nanotubes) and PLA/HNT (halloysite nanotubes) nanocomposites, as a reference for application in 3D printing processes. Design/methodology/approach Nanocomposites were obtained by melting in a twin-screw extruder, mixing PLA with MWCNTs and HNTs in different percentages of 0.5, 0.75 and 1 Wt.% for subsequent mixing by the same process with 5 phr MLO, for application in additive manufacturing, as analyzed by means of differential scanning calorimetry (DSC), capillary rheometry, melt flow rate (MFL) and field emission scanning electron microscopy (FESEM). Findings The results obtained for thermal characterization by using DSC indicate the non-variation of glass transition temperature Tg = 62 ± 2°C and a melting temperature (Tm) around 170°C. Crystallization temperature dropped by approxi...
Polymers, 2019
This research work aims to study the influence of the reprocessing cycles on the mechanical, ther... more This research work aims to study the influence of the reprocessing cycles on the mechanical, thermal, and thermomechanical properties of polylactide (PLA). To this end, PLA was subjected to as many as six extrusion cycles and the resultant pellets were shaped into pieces by injection molding. Mechanical characterization revealed that the PLA pieces presented relatively similar properties up to the third reprocessing cycle, whereas further cycles induced an intense reduction in ductility and toughness. The effect of the reprocessing cycles was also studied by the changes in the melt fluidity, which showed a significant increase after four reprocessing cycles. An increase in the bio-polyester chain mobility was also attained with the number of the reprocessing cycles that subsequently favored an increase in crystallinity of PLA. A visual inspection indicated that PLA developed certain yellowing and the pieces also became less transparent with the increasing number of reprocessing cycl...
Polymer International, 2019
The cover image is based on the Research Article Effect of different compatibilizers on environme... more The cover image is based on the Research Article Effect of different compatibilizers on environmentally friendly composites from poly(lactic acid) and diatomaceous earth by Angel Aguero et al. DOI: 10.1002/pi.5779. image
Journal of Polymers and the Environment, 2019
European Polymer Journal, 2018
The present study describes the effect of maleinized hemp seed oil (MHO) on the physical performa... more The present study describes the effect of maleinized hemp seed oil (MHO) on the physical performance of polylactide (PLA) pieces. To this end, PLA pieces with varying MHO contents in the 0-10 wt% range were manufactured by twin-screw extrusion (TSE) followed by injection molding. The resultant pieces were characterized in terms of their mechanical, thermal, and thermomechanical properties. The obtained properties suggested that, unlike typical plasticizers, MHO does not only induce an increment in elongation at break and impact strength but it also enhances both elastic modulus and tensile strength. In addition, it was observed a moderate decrease in the glass transition temperature (Tg). This was ascribed to a linear chain extension and/or branching phenomenon due to the reaction of the multiple maleic anhydride (MAH) groups present in MHO with the hydroxyl groups of the PLA terminal chains. Furthermore, morphology characterization revealed that, though certain phase separation occurred at its highest content, MHO was finely dispersed as submicron droplets within the PLA matrix contributing to improving toughness. The use of multi-functionalized reactive oils thus represents a highly sustainable solution to reduce the intrinsic brittleness of PLA materials without compromising their mechanical resistance and the toughened biopolymer pieces described herein can find interesting applications in, for instance, rigid packaging.
Polymer International, 2017
The use of maleinized linseed oil (MLO) as a potential biobased plasticizer for poly(lactic acid)... more The use of maleinized linseed oil (MLO) as a potential biobased plasticizer for poly(lactic acid) (PLA) industrial formulations with improved toughness was evaluated. MLO content varied in the range 0–20 phr (parts by weight of MLO per hundred parts by weight of PLA). Mechanical, thermal and morphological characterizations were used to assess the potential of MLO as an environmentally friendly plasticizer for PLA formulations. Dynamic mechanical thermal analysis and differential scanning calorimetry revealed a noticeable decrease in the glass transition temperature of about 6.5 °C compared to neat PLA. In addition, the cold crystallization process was favoured with MLO content due to the increased chain mobility that the plasticizer provides. PLA toughness was markedly improved in formulations with 5 phr MLO, while maximum elongation at break was obtained for PLA formulations plasticized with MLO content in the range 15–20 phr. Scanning electron microscopy revealed evidence of plast...
Materials & Design, 2016
Renewable vinyl plastisol composites based on epoxidized linseed oil (ELO) were developed by intr... more Renewable vinyl plastisol composites based on epoxidized linseed oil (ELO) were developed by introducing reed wood flour • Optimal materials were observed for vinyl plastisol composites containing 20 to 30 wt.-% of wood flour particles of 500 μm • Wood flour was exposed to ultraviolet (UV) radiation to increase its interfacial adhesion with the vinyl plastisol • Ductility of the vinyl plastisol composites prepared with UV-exposed wood flour for 4 min increased up to 3.5 times.
Polymer International, 2016
In this work, binary blends based on poly(lactic acid)-PLA and poly(caprolactone)-PCL were prepar... more In this work, binary blends based on poly(lactic acid)-PLA and poly(caprolactone)-PCL were prepared by melt mixing in a twin screw co-rotating extruder in order to increase the low intrinsic elongation at break of PLA for packaging applications. Although PLA and PCL show low miscibility, presence of PCL leads to a remarkable increase in ductile properties of PLA. Different mechanical properties were evaluated in terms of PCL content up to 30 weight % PCL. Additionally to tensile and flexural properties, the Poisson's ratio was obtained by using bi-axial extensometry to evaluate transversal deformations when axial loads are applied. Very slight changes in the melt temperature (T m) and glass transition temperature (T g) of PLA were observed thus indicating low miscibility of the PLA-PCL system. Field emission scanning electron microscopy (FESEM) revealed some interactions between the two components of the blend since the morphology is characterized by non-spherical poly(caprolactone) drops dispersed into the PLA matrix. In addition to the improvement of mechanical ductile properties, PCL provides higher degradation rates of blends under conditions of composting for contents below 22.5% PCL.
Composites Part B: Engineering, 2016
Different amounts of epoxidized linseed oil (ELO) have been added to poly(lactic acid)-PLA compos... more Different amounts of epoxidized linseed oil (ELO) have been added to poly(lactic acid)-PLA composites with hazelnut shell flour (HSF) to provide a plasticizing effect and improve the low intrinsic ductile properties of PLA/HSF composites. Mechanical, thermal, thermo-mechanical and dynamic mechanical properties have been studied in terms of the weight percentage ELO. Mechanical resistant properties in both tensile and flexural tests decrease with wt.% ELO while a remarkable increase with wt.% ELO is obtained. These results reveal a clear plasticization effect of ELO but, in addition, internal structure of PLA/HSF/ELO composites shows good PLA-HSF (matrix-particle) interactions so that indicating that ELO also provides a coupling effect between PLA matrix and HSF filler. ELO addition leads to a decrease in storage modulus (G') obtained by dynamic mechanical thermal analysis (DMTA) in torsion mode thus giving clear evidence of the plasticization effect of ELO. Overall, the use of ELO in PLA/HSF composites is an attracting way to improve the low intrinsic fragility of these green
Polymer Composites, 2014
In the present study the valorization of wastes from Posidonia oceanica (PO) has been carried out... more 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...