Pub Date : 2022-01-01DOI: 10.1177/09673911211069019
Ramin Riahipour, Mohammad Saber Nemati, Mehdi Zadehmohamad, M. Abadyan, M. Tehrani, M. Baniassadi
Flame retardant (FR) additives may degrade polymers’ mechanical performance. In this work, FR epoxy composites fabricated based on two popular FR agents of ammonium polyphosphate (APP) and silica aerogel (SAG) are investigated. Several mechanical properties of these composites, including compressive, micro-hardness, and Izod impact, were investigated for different filler loadings. Although the addition of 10 vol.% APP improved compressive modulus, yield strength, and micro-hardness, it degraded the impact strength. The incorporation of SAG made the composites more ductile, improved the impact strength, but deteriorated their compressive properties. Samples containing both SAG and APP demonstrated synergetic effects evident by their enhanced compressive properties and hardness. The findings of this study can guide the design of epoxies with both exceptional FR and mechanical performance.
{"title":"Mechanical properties of an epoxy-based coating reinforced with silica aerogel and ammonium polyphosphate additives","authors":"Ramin Riahipour, Mohammad Saber Nemati, Mehdi Zadehmohamad, M. Abadyan, M. Tehrani, M. Baniassadi","doi":"10.1177/09673911211069019","DOIUrl":"https://doi.org/10.1177/09673911211069019","url":null,"abstract":"Flame retardant (FR) additives may degrade polymers’ mechanical performance. In this work, FR epoxy composites fabricated based on two popular FR agents of ammonium polyphosphate (APP) and silica aerogel (SAG) are investigated. Several mechanical properties of these composites, including compressive, micro-hardness, and Izod impact, were investigated for different filler loadings. Although the addition of 10 vol.% APP improved compressive modulus, yield strength, and micro-hardness, it degraded the impact strength. The incorporation of SAG made the composites more ductile, improved the impact strength, but deteriorated their compressive properties. Samples containing both SAG and APP demonstrated synergetic effects evident by their enhanced compressive properties and hardness. The findings of this study can guide the design of epoxies with both exceptional FR and mechanical performance.","PeriodicalId":20417,"journal":{"name":"Polymers and Polymer Composites","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89460646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1177/09673911221093991
Y. Budash, N. Rezanova, V. Plavan, Viktoriia Rezanova
The influence of the concentration of thermally and organomodified montmorillonite on the processes of structure formation in a blend of polypropylene/polystyrene (PP/PS) was studied. It is established that in nanofilled compositions, as well as in the original, is formed a microfibrillar structure, the dimensional characteristics of which depend on the content of the additive and the method of its modification. The investigated clays by content (0.2–2.0) wt. % by weight of polypropylene have a compatibilizing effect in the blend of PP/PS, which reduces the average diameter of microfibers by 1.6 times and increases the homogeneity of their distribution by diameter: statistical indicators decrease (standard deviation, variance, coefficient of variation). The modifying effect of thermally modified clay is higher—the improvement of the dimensional characteristics of PP microfibers is achieved at its minimum content in the blend (0.2 wt. %). The formation of anisotropic PP structures in the PS matrix and the relaxation of the accumulated stresses at the exit of the molding hole is the main factor that causes high values of the coefficient of swelling of the extrudates (4.0–7.7). The change in the microstructure of the extrudates of nanofilled systems during spinning depends on the composition of the blend and the method of modification of montmorillonite. The average diameters of microfibers decrease from 2.2 μm (in the original blend) to (1.3–2.0) μm (in three-component) depending on the content of additives. The ability to regulate the microstructure of incompatible polymer blends by introducing additives of thermally and organomodified montmorillonite will contribute to the creation of nanocomposites with controlled morphology, as well as new fine-fiber materials with improved filtering characteristics.
{"title":"Thermally and organomodified montmorillonite as effective regulators of the structure formation process in polypropylene/polystyrene blends","authors":"Y. Budash, N. Rezanova, V. Plavan, Viktoriia Rezanova","doi":"10.1177/09673911221093991","DOIUrl":"https://doi.org/10.1177/09673911221093991","url":null,"abstract":"The influence of the concentration of thermally and organomodified montmorillonite on the processes of structure formation in a blend of polypropylene/polystyrene (PP/PS) was studied. It is established that in nanofilled compositions, as well as in the original, is formed a microfibrillar structure, the dimensional characteristics of which depend on the content of the additive and the method of its modification. The investigated clays by content (0.2–2.0) wt. % by weight of polypropylene have a compatibilizing effect in the blend of PP/PS, which reduces the average diameter of microfibers by 1.6 times and increases the homogeneity of their distribution by diameter: statistical indicators decrease (standard deviation, variance, coefficient of variation). The modifying effect of thermally modified clay is higher—the improvement of the dimensional characteristics of PP microfibers is achieved at its minimum content in the blend (0.2 wt. %). The formation of anisotropic PP structures in the PS matrix and the relaxation of the accumulated stresses at the exit of the molding hole is the main factor that causes high values of the coefficient of swelling of the extrudates (4.0–7.7). The change in the microstructure of the extrudates of nanofilled systems during spinning depends on the composition of the blend and the method of modification of montmorillonite. The average diameters of microfibers decrease from 2.2 μm (in the original blend) to (1.3–2.0) μm (in three-component) depending on the content of additives. The ability to regulate the microstructure of incompatible polymer blends by introducing additives of thermally and organomodified montmorillonite will contribute to the creation of nanocomposites with controlled morphology, as well as new fine-fiber materials with improved filtering characteristics.","PeriodicalId":20417,"journal":{"name":"Polymers and Polymer Composites","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89646333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1177/09673911221076721
M. Raj, Jaykumar Maheta, L. Raj
Current study compares the various analytical results of hexafunctional epoxy resins based on bisphenol-A with conventional epoxy resins. Reaction of bisphenol-A, formaldehyde, and epichlorohydrin produces hexafunctional epoxy resin. The curing properties of commercial epoxy resin and hexafunctional epoxy resin were determined using a variety of hardeners, including diethylenetriamine, triethylenetetramine, phenalkamine, polyamido amines, and polyamides. The epoxy equivalent weight (EEW), hydrolyzable chlorine content, volatile content, Brookfield viscosity, weight average molecular weight, elemental analysis (C, H, N, O analysis), and Fourier transform infrared spectroscopy were used to characterize the hexafunctional resin (FT-IR). Jute and glass reinforced composites were also prepared by using hexafunctional epoxy resins and commercial epoxy resins. Mechanical properties (tensile strength, flexural strength, Izod impact strength, and Rockwell hardness), thermal properties, and chemical resistance were determined for each composite. Hexafunctional epoxy resin-based composites exhibited superior mechanical characteristics, thermal resistance, and chemical resistance properties than commercial epoxy resin-based composites.
{"title":"Synthesis characterization and application of hexafunctional epoxy resin and comparison against commercial epoxy resin","authors":"M. Raj, Jaykumar Maheta, L. Raj","doi":"10.1177/09673911221076721","DOIUrl":"https://doi.org/10.1177/09673911221076721","url":null,"abstract":"Current study compares the various analytical results of hexafunctional epoxy resins based on bisphenol-A with conventional epoxy resins. Reaction of bisphenol-A, formaldehyde, and epichlorohydrin produces hexafunctional epoxy resin. The curing properties of commercial epoxy resin and hexafunctional epoxy resin were determined using a variety of hardeners, including diethylenetriamine, triethylenetetramine, phenalkamine, polyamido amines, and polyamides. The epoxy equivalent weight (EEW), hydrolyzable chlorine content, volatile content, Brookfield viscosity, weight average molecular weight, elemental analysis (C, H, N, O analysis), and Fourier transform infrared spectroscopy were used to characterize the hexafunctional resin (FT-IR). Jute and glass reinforced composites were also prepared by using hexafunctional epoxy resins and commercial epoxy resins. Mechanical properties (tensile strength, flexural strength, Izod impact strength, and Rockwell hardness), thermal properties, and chemical resistance were determined for each composite. Hexafunctional epoxy resin-based composites exhibited superior mechanical characteristics, thermal resistance, and chemical resistance properties than commercial epoxy resin-based composites.","PeriodicalId":20417,"journal":{"name":"Polymers and Polymer Composites","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75485417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1177/09673911221078481
A. Sayyidmousavi, Z. Fawaz
Aiming for the development of experimentally validated computational models to predict the mechanical properties of 3D-printed composites, the present study proposes a micromechanical approach by using a simplified unit cell model to characterize the material properties and behavior of 3D-printed composites manufactured through fused deposition modeling. The effective properties of the voided polymer matrix phase of the material are computed by calculating the void density as a tensorial meso-structural variable. These effective properties along with those of the fiber are input into a simplified micromechanical model to predict the material properties of the 3D-printed composite. The predictions are seen to be in very good agreement with the experimental values. The present approach is much simpler and less computationally costly compared to the finite element homogenization method. In addition, the present approach has the potential to simulate the response of the 3D-printed composite under different loading conditions.
{"title":"A micromechanical approach to the mechanical characterization of 3D-printed composites","authors":"A. Sayyidmousavi, Z. Fawaz","doi":"10.1177/09673911221078481","DOIUrl":"https://doi.org/10.1177/09673911221078481","url":null,"abstract":"Aiming for the development of experimentally validated computational models to predict the mechanical properties of 3D-printed composites, the present study proposes a micromechanical approach by using a simplified unit cell model to characterize the material properties and behavior of 3D-printed composites manufactured through fused deposition modeling. The effective properties of the voided polymer matrix phase of the material are computed by calculating the void density as a tensorial meso-structural variable. These effective properties along with those of the fiber are input into a simplified micromechanical model to predict the material properties of the 3D-printed composite. The predictions are seen to be in very good agreement with the experimental values. The present approach is much simpler and less computationally costly compared to the finite element homogenization method. In addition, the present approach has the potential to simulate the response of the 3D-printed composite under different loading conditions.","PeriodicalId":20417,"journal":{"name":"Polymers and Polymer Composites","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78335939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1177/09673911221082482
F. Tanjung, R. A. Kuswardani, C. I. Idumah, J. Siregar, A. Karim
A comparative study was performed on the use of esterified alkaline lignin (AAL) and esterified organosolv lignin (AOSL) as the interfacial modifying agent to improve the properties of polypropylene-chitosan composites. Chitosan was chemically modified through a reaction with the esterified lignin in an alcohol medium. The composites were prepared using an internal mixer and hot-pressed method. Both modified chitosan showed a different chemical structure upon modification with the esterified lignins as confirmed by Fourier transform infrared spectroscopy spectra. With a lower molecular weight, the AOSL attachment on the chitosan surface resulted in more efficiency in decreasing hydrophilic characters. Tensile tests showed the increased tensile strength by 32.15% and 26.43% for AOSL-modified composites and AAL-modified composites as compared with the unmodified composites. Overall, the AOSL was superior in improving the mechanical strength and thermal stability of the composites, while the AAL exhibited the most apparent enhancement in ductility and crystallization.
{"title":"Characterization of mechanical and thermal properties of esterified lignin modified polypropylene composites filled with chitosan fibers","authors":"F. Tanjung, R. A. Kuswardani, C. I. Idumah, J. Siregar, A. Karim","doi":"10.1177/09673911221082482","DOIUrl":"https://doi.org/10.1177/09673911221082482","url":null,"abstract":"A comparative study was performed on the use of esterified alkaline lignin (AAL) and esterified organosolv lignin (AOSL) as the interfacial modifying agent to improve the properties of polypropylene-chitosan composites. Chitosan was chemically modified through a reaction with the esterified lignin in an alcohol medium. The composites were prepared using an internal mixer and hot-pressed method. Both modified chitosan showed a different chemical structure upon modification with the esterified lignins as confirmed by Fourier transform infrared spectroscopy spectra. With a lower molecular weight, the AOSL attachment on the chitosan surface resulted in more efficiency in decreasing hydrophilic characters. Tensile tests showed the increased tensile strength by 32.15% and 26.43% for AOSL-modified composites and AAL-modified composites as compared with the unmodified composites. Overall, the AOSL was superior in improving the mechanical strength and thermal stability of the composites, while the AAL exhibited the most apparent enhancement in ductility and crystallization.","PeriodicalId":20417,"journal":{"name":"Polymers and Polymer Composites","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74116527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1177/09673911221106047
M. Gaur, R. Raghav, R. Sagar, R. Tiwari
The bisphenol A diglycidyl ether-polyaminoamide (epoxy resin)–graphene oxide (GO) nanocomposites have been prepared by chemical methods. The aim of this study is to produce epoxy –GO coatings on Aluminum Alloy 7075 and study the anticorrosion properties. Thin films have been characterized by scanning electron microscope – Energy Dispersive X-rays Spectroscopy (EDX) and Raman spectra. Raman spectra show the successful bonding of GO functional groups with epoxy. The composition of epoxy and GO is characterized by EDX. The Tafel plots were undertaken for analysis of corrosion of coating material. Therefore, the reduction of corrosion current of epoxy–GO nanocomposites coated Al alloy 7075 show its superior corrosion resistance properties. This is further confirmed by electrochemical impedance spectroscopy and potentiodynamic polarization. The very high value of low frequency impedance modulus (i.e. 1010 Ω cm2) shows surprising anticorrosive effect on coating. The epoxy–GO spin coating in Al Alloy 7075 is significantly reduces the corrosion current density (Icorr) and corrosion rate due to anticorrosion properties of GO.
{"title":"Investigation of anticorrosion properties of epoxy GO nanocomposites spin coated Aluminum Alloy 7075","authors":"M. Gaur, R. Raghav, R. Sagar, R. Tiwari","doi":"10.1177/09673911221106047","DOIUrl":"https://doi.org/10.1177/09673911221106047","url":null,"abstract":"The bisphenol A diglycidyl ether-polyaminoamide (epoxy resin)–graphene oxide (GO) nanocomposites have been prepared by chemical methods. The aim of this study is to produce epoxy –GO coatings on Aluminum Alloy 7075 and study the anticorrosion properties. Thin films have been characterized by scanning electron microscope – Energy Dispersive X-rays Spectroscopy (EDX) and Raman spectra. Raman spectra show the successful bonding of GO functional groups with epoxy. The composition of epoxy and GO is characterized by EDX. The Tafel plots were undertaken for analysis of corrosion of coating material. Therefore, the reduction of corrosion current of epoxy–GO nanocomposites coated Al alloy 7075 show its superior corrosion resistance properties. This is further confirmed by electrochemical impedance spectroscopy and potentiodynamic polarization. The very high value of low frequency impedance modulus (i.e. 1010 Ω cm2) shows surprising anticorrosive effect on coating. The epoxy–GO spin coating in Al Alloy 7075 is significantly reduces the corrosion current density (Icorr) and corrosion rate due to anticorrosion properties of GO.","PeriodicalId":20417,"journal":{"name":"Polymers and Polymer Composites","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81742696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1177/09673911221100968
Orhan Kelleci, D. Aydemir, Ertuğrul Altuntaş, Ahmet Oztel, R. Kurt, Huseyin Yorur, A. Istek
In this study, blends of polypropylene (PP) with polylactic acid (PLA) and polyhydroxybutyrate (PHB) biopolymers and wood flour were prepared, and Fuzzy and Grey Multi-Criteria Decision-Making (MCDM) methods were used to determine the blends with the best properties. The physical, mechanical, thermal, structural, and morphological properties of the composites were determined. The obtained results showed that PLA and wood flour generally improved the mechanical properties of the PP composites. However, wood flour did not exhibit a homogeneous distribution in the matrix. The density of the composites generally increased with the addition of both PLA and PHB. X-ray diffraction analysis showed that the crystallinity index of the composites generally decreased due to the low crystallinity of biopolymers. Thermal stability did not change with the addition of PLA and PHB, but the addition of wood increased thermal stability. According to the MCDM analysis, both Fuzzy and Grey results were similar.
{"title":"Thermoplastic composites of polypropylene/biopolymer blends and wood flour: Parameter optimization with fuzzy-grey relational analysis","authors":"Orhan Kelleci, D. Aydemir, Ertuğrul Altuntaş, Ahmet Oztel, R. Kurt, Huseyin Yorur, A. Istek","doi":"10.1177/09673911221100968","DOIUrl":"https://doi.org/10.1177/09673911221100968","url":null,"abstract":"In this study, blends of polypropylene (PP) with polylactic acid (PLA) and polyhydroxybutyrate (PHB) biopolymers and wood flour were prepared, and Fuzzy and Grey Multi-Criteria Decision-Making (MCDM) methods were used to determine the blends with the best properties. The physical, mechanical, thermal, structural, and morphological properties of the composites were determined. The obtained results showed that PLA and wood flour generally improved the mechanical properties of the PP composites. However, wood flour did not exhibit a homogeneous distribution in the matrix. The density of the composites generally increased with the addition of both PLA and PHB. X-ray diffraction analysis showed that the crystallinity index of the composites generally decreased due to the low crystallinity of biopolymers. Thermal stability did not change with the addition of PLA and PHB, but the addition of wood increased thermal stability. According to the MCDM analysis, both Fuzzy and Grey results were similar.","PeriodicalId":20417,"journal":{"name":"Polymers and Polymer Composites","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80834328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1177/09673911221102114
H. Hu, W. Wang, Liqin Jiang, Liang Liu, Y. Zhang, Y. Yang, Jinming Wang
To solve the problem that the curing mechanism evolution of phenolic resin catalyzed by Ba(OH)2 remained unclear, the p-p methylene index, o-p methylene index, o-o methylene index, hydroxymethyl index, and ether index were introduced to quantitatively investigate the chemical structure of resin in the curing temperature range of 90–230°C. The chemical structures were investigated by variable temperature FT-IR. The gas products released with the increase of curing temperature were characterized by Thermogravimetry-Mass Spectrometry. The curing mechanism from 90°C to 230°C was concluded finally. The results show that the main reaction is the formation of the p-p methylene group in the range of 90–120°C. It is difficult to form the o-p methylene bridge at this stage. In the range of 120–160°C, the main reaction is the formation of the p-p methylene group. From 160°C to 190°C, the main reactions are the breaking of the ether bond, the formation of the carbonyl group and the propyl bridge. Above 190°C, the main reactions are polycondensation reaction among phenolic hydroxyl groups, and the formation reaction of carbonyl groups. The ether bond breaks completely above 230°C. This work provides a new method to investigate the curing mechanism. It is a benefit for the rational design of the curing process of phenolic resin-based composites.
{"title":"Curing mechanism of resole phenolic resin based on variable temperature FTIR spectra and thermogravimetry-mass spectrometry","authors":"H. Hu, W. Wang, Liqin Jiang, Liang Liu, Y. Zhang, Y. Yang, Jinming Wang","doi":"10.1177/09673911221102114","DOIUrl":"https://doi.org/10.1177/09673911221102114","url":null,"abstract":"To solve the problem that the curing mechanism evolution of phenolic resin catalyzed by Ba(OH)2 remained unclear, the p-p methylene index, o-p methylene index, o-o methylene index, hydroxymethyl index, and ether index were introduced to quantitatively investigate the chemical structure of resin in the curing temperature range of 90–230°C. The chemical structures were investigated by variable temperature FT-IR. The gas products released with the increase of curing temperature were characterized by Thermogravimetry-Mass Spectrometry. The curing mechanism from 90°C to 230°C was concluded finally. The results show that the main reaction is the formation of the p-p methylene group in the range of 90–120°C. It is difficult to form the o-p methylene bridge at this stage. In the range of 120–160°C, the main reaction is the formation of the p-p methylene group. From 160°C to 190°C, the main reactions are the breaking of the ether bond, the formation of the carbonyl group and the propyl bridge. Above 190°C, the main reactions are polycondensation reaction among phenolic hydroxyl groups, and the formation reaction of carbonyl groups. The ether bond breaks completely above 230°C. This work provides a new method to investigate the curing mechanism. It is a benefit for the rational design of the curing process of phenolic resin-based composites.","PeriodicalId":20417,"journal":{"name":"Polymers and Polymer Composites","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80850580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1177/09673911221087591
Vilson Dalla Libera Junior, L. A. Teixeira, S. Amico, Sandra Maria da Luz
This work manufactured prepregs by impregnating discontinuous curaua fibers with B-stage epoxy resin. The prepreg layers were then stacked to produce laminates by hot compression. Alkaline treatments were previously applied to the curaua fibers to improve their interface with the polymer matrix. Then, the prepregs and the final composites were studied regarding their thermal, dynamic mechanical, mechanical, and morphological behavior. The treatments promoted defibrillation by removing lignin and hemicellulose from the fibers, which allowed better impregnation of the treated fibers with epoxy resin. In general, laminates that used treated fibers exhibited the largest storage modulus in the glassy region. The mechanical results showed the laminates produced with treated fibers prepregs presented a highest tensile and flexural resistance than those manufactured with untreated fibers and neat epoxy resin. The NaOH-treated curaua/epoxy laminate exhibited high tensile strength (56.2 MPa) and modulus (3.3 GPa). Overall, fracture morphology indicated better fiber adhesion for the treated fiber composites. The results demonstrate that natural fibers prepregs can be successfully produced and present proper physical and mechanical behavior in components.
{"title":"Processing, thermal and mechanical properties of composite laminates with natural fibers prepregs","authors":"Vilson Dalla Libera Junior, L. A. Teixeira, S. Amico, Sandra Maria da Luz","doi":"10.1177/09673911221087591","DOIUrl":"https://doi.org/10.1177/09673911221087591","url":null,"abstract":"This work manufactured prepregs by impregnating discontinuous curaua fibers with B-stage epoxy resin. The prepreg layers were then stacked to produce laminates by hot compression. Alkaline treatments were previously applied to the curaua fibers to improve their interface with the polymer matrix. Then, the prepregs and the final composites were studied regarding their thermal, dynamic mechanical, mechanical, and morphological behavior. The treatments promoted defibrillation by removing lignin and hemicellulose from the fibers, which allowed better impregnation of the treated fibers with epoxy resin. In general, laminates that used treated fibers exhibited the largest storage modulus in the glassy region. The mechanical results showed the laminates produced with treated fibers prepregs presented a highest tensile and flexural resistance than those manufactured with untreated fibers and neat epoxy resin. The NaOH-treated curaua/epoxy laminate exhibited high tensile strength (56.2 MPa) and modulus (3.3 GPa). Overall, fracture morphology indicated better fiber adhesion for the treated fiber composites. The results demonstrate that natural fibers prepregs can be successfully produced and present proper physical and mechanical behavior in components.","PeriodicalId":20417,"journal":{"name":"Polymers and Polymer Composites","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80919858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.1177/09673911221101698
A. Kareem
In this work, silver (Ag) self-metallization on a polyimide (PI) film was prepared through autocatalytic plating. PI films were prepared through the solution casting method, followed by etching with potassium hydroxide (KOH) solution, sensitization with tin chloride (SnCl2), and the use of palladium chloride (PdCl2) to activate the surface of PI. Energy-dispersive X-ray analysis (EDX) showed the highest peak in the (Ag) region and confirmed the presence of AgNPs. The diffraction peaks at 2θ = 38.2°, 44.5°, 64.6°, and 78.2° represented the 111, 200, 220, and 311 planes of Ag, respectively. The FT–IR analysis for Ag-metalized PI showed that the =C-O-C= stretching absorption bands at 1735 cm−1 had no changes in position, only a significant difference in peak size at the deposition time increase. The formation of new bands (N–H stretching absorption band and N–C stretching band) assigned at 2325 and 955 cm−1 indicated strong coordination between N atoms and silver nanoparticles. The C–C stretching and = C–H plane vibration band at 1488 and 1117 cm−1 are shifted to 1413 and 1112 cm−1, indicating the silver nanoparticles' interaction with the polymer backbone. The thermal stability of PI- and Ag-metalized PI films at various deposition times (5, 10, and 15 min) was examined using thermogravimetric analysis (TGA). For PI, T0, T5, T10, and Tmax were observed to be 388°C, 402°C, 414°C, and 515°C, respectively. When the deposition time increased, the thermal stability increased. As a function of the deposition, the thickness and surface morphology of the copper layer on the PI films were characterized using scanning electron microscopy (SEM).
{"title":"Preparation and characterization of silver self-metallization on polyimide","authors":"A. Kareem","doi":"10.1177/09673911221101698","DOIUrl":"https://doi.org/10.1177/09673911221101698","url":null,"abstract":"In this work, silver (Ag) self-metallization on a polyimide (PI) film was prepared through autocatalytic plating. PI films were prepared through the solution casting method, followed by etching with potassium hydroxide (KOH) solution, sensitization with tin chloride (SnCl2), and the use of palladium chloride (PdCl2) to activate the surface of PI. Energy-dispersive X-ray analysis (EDX) showed the highest peak in the (Ag) region and confirmed the presence of AgNPs. The diffraction peaks at 2θ = 38.2°, 44.5°, 64.6°, and 78.2° represented the 111, 200, 220, and 311 planes of Ag, respectively. The FT–IR analysis for Ag-metalized PI showed that the =C-O-C= stretching absorption bands at 1735 cm−1 had no changes in position, only a significant difference in peak size at the deposition time increase. The formation of new bands (N–H stretching absorption band and N–C stretching band) assigned at 2325 and 955 cm−1 indicated strong coordination between N atoms and silver nanoparticles. The C–C stretching and = C–H plane vibration band at 1488 and 1117 cm−1 are shifted to 1413 and 1112 cm−1, indicating the silver nanoparticles' interaction with the polymer backbone. The thermal stability of PI- and Ag-metalized PI films at various deposition times (5, 10, and 15 min) was examined using thermogravimetric analysis (TGA). For PI, T0, T5, T10, and Tmax were observed to be 388°C, 402°C, 414°C, and 515°C, respectively. When the deposition time increased, the thermal stability increased. As a function of the deposition, the thickness and surface morphology of the copper layer on the PI films were characterized using scanning electron microscopy (SEM).","PeriodicalId":20417,"journal":{"name":"Polymers and Polymer Composites","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90043852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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