scholarly journals Studying the Effects of Adding Silica Sand Nanoparticles on Epoxy Based Composites

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Tahir Ahmad ◽  
Othman Mamat ◽  
Rafiq Ahmad
Keyword(s):  
Mechanical Properties ◽  
Polymer Matrix Composite ◽  
Silica Sand ◽  
Degree Of Crystallinity ◽  
Dsc Analysis ◽  
Scanning Calorimetry ◽  
Inorganic Particles ◽  
The Past ◽  
The Subject ◽  
Experimental Values

The research about the preparation of submicron inorganic particles, once conducted in the past decade, is now leading to prepare polymer matrix composite (PMC) reinforced with nanofillers. The objective of present research is to study the modified effects of reinforcement dispersion of nanoparticle silica in epoxy resin on the physical properties, mechanical and thermal behaviour, and the microstructure of resultant composites. Stirrer mixing associated with manual mixing of silica sand nanoparticles (developed in our earlier research) (Ahmad and Mamat, 2012) into epoxy was followed by curing being the adopted technique to develop the subject nanocomposites. Experimental values showed that 15 wt.% addition of silica sand nanoparticles improves Young’s modulus of the composites; however, a reduction in tensile strength was also observed. Number of holes and cavities produced due to improper mixing turn out to be the main cause of effected mechanical properties. Addition of silica sand nanoparticles causes a reduction in degree of crystallinity of the nanocomposites as being observed in differential scanning calorimetry (DSC) analysis.

scholarly journals Post-Processing Time Dependence of Shrinkage and Mechanical Properties of Injection-Molded Polypropylene

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 22
Author(s):  
Artur Kościuszko ◽  
Dawid Marciniak ◽  
Dariusz Sykutera
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Injection Molding ◽  
Accelerated Aging ◽  
Mold Temperature ◽  
Degree Of Crystallinity ◽  
Injection Mold ◽  
Secondary Crystallization ◽  
Scanning Calorimetry ◽  
Injection Molded

Dimensions of the injection-molded semi-crystalline materials (polymeric products) decrease with the time that elapses from their formation. The post-molding shrinkage is an effect of secondary crystallization; the increase in the degree of polymer crystallinity leads to an increase in stiffness and decrease in impact strength of the polymer material. The aim of this study was to assess the changes in the values of post-molding shrinkage of polypropylene produced by injection molding at two different temperatures of the mold (20 °C and 80 °C), and conditioned for 504 h at 23 °C. Subsequently, the samples were annealed for 24 h at 140 °C in order to conduct their accelerated aging. The results of shrinkage tests were related to the changes of mechanical properties that accompany the secondary crystallization. The degree of crystallinity of the conditioned samples was determined by means of density measurements and differential scanning calorimetry. It was found that the changes in the length of the moldings that took place after removal from the injection mold were accompanied by an increase of 20% in the modulus of elasticity, regardless of the conditions under which the samples were made. The differences in the shrinkage and mechanical properties of the samples resulting from mold temperature, as determined by tensile test, were removed by annealing. However, the samples made at two different injection mold temperature values still significantly differed in impact strength, the values of which were clearly higher for the annealed samples compared to the results determined for the samples immediately after the injection molding.

scholarly journals Combined Effects of Cellulose Nanofiber Nucleation and Maleated Polylactic Acid Compatibilization on the Crystallization Kinetic and Mechanical Properties of Polylactic Acid Nanocomposite

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3226
Author(s):  
Siti Shazra Shazleen ◽  
Lawrence Yee Foong Ng ◽  
Nor Azowa Ibrahim ◽  
Mohd Ali Hassan ◽  
Hidayah Ariffin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Polylactic Acid ◽  
Crystallization Kinetics ◽  
Crystallization Kinetic ◽  
Crystallization Rate ◽  
Combined Effects ◽  
Dsc Analysis ◽  
Scanning Calorimetry ◽  
Isothermal Crystallization Kinetics

This work investigated the combined effects of CNF nucleation (3 wt.%) and PLA-g-MA compatibilization at different loadings (1–4 wt.%) on the crystallization kinetics and mechanical properties of polylactic acid (PLA). A crystallization kinetics study was done through isothermal and non-isothermal crystallization kinetics using differential scanning calorimetry (DSC) analysis. It was shown that PLA-g-MA had some effect on nucleation as exhibited by the value of crystallization half time and crystallization rate of the PLA/PLA-g-MA, which were increased by 180% and 172%, respectively, as compared to neat PLA when isothermally melt crystallized at 100 °C. Nevertheless, the presence of PLA-g-MA in PLA/PLA-g-MA/CNF3 nanocomposites did not improve the crystallization rate compared to that of uncompatibilized PLA/CNF3. Tensile strength was reduced with the increased amount of PLA-g-MA. Contrarily, Young’s modulus values showed drastic increment compared to the neat PLA, showing that the addition of the PLA-g-MA contributed to the rigidity of the PLA nanocomposites. Overall, it can be concluded that PLA/CNF nanocomposite has good performance, whereby the addition of PLA-g-MA in PLA/CNF may not be necessary for improving both the crystallization kinetics and tensile strength. The addition of PLA-g-MA may be needed to produce rigid nanocomposites; nevertheless, in this case, the crystallization rate of the material needs to be compromised.

CONNECTION BETWEEN STRUCTURAL CHANGES OF IRRIADIATED POLYETHER ETHER KETONE AND MECHANICAL PROPERTIES

Tribologia ◽  
2018 ◽  
Vol 278 (2) ◽  
pp. 95-101
Author(s):  
Aneta NIEMIEC
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Structural Changes ◽  
Radiation Energy ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Polyether Ether Ketone ◽  
Ether Ketone ◽  
The Impact ◽  
The Degree Of Crystallinity

The article presents the results of research on the impact of structural changes in polyether ether ketone (PEEK) on its mechanical properties. The polymer was exposed to gamma radiation at a dose of 50 and 150 kGy, and the radiation energy was 4 MeV. Changes in the degree of crystallinity and the related changes in the glass transition and melting temperature for the polymer were determined by differential scanning calorimetry (DSC). Mechanical properties were determined using the micro-mentoring method. The tests showed a change in the degree of crystallinity in the range of several degrees and a significant increase in the glass transition temperature. In terms of mechanical properties, the reduction of hardness and Young’s modulus was observed. Observed changes, especially in terms of changes in the structure of the polymer under the influence of radiation, are difficult to explain, which requires conducting further research, especially in the range of irradiation parameters used. Further research is important because PEEK is used in many fields, especially in conditions conducive to corrosion and the influence of radiation.

Thermal, morphological and mechanical properties of composites based on polyamide 6 with cellulose, silica and their hybrids from rice husk

2020 ◽  
pp. 002199832097829
Author(s):  
Renato P Melo ◽  
Marcelo P da Rosa ◽  
Paulo H Beck ◽  
Lucas GP Tienne ◽  
Maria de Fátima V Marques
Keyword(s):  
Mechanical Properties ◽  
Rice Husk ◽  
Natural Fibers ◽  
Polyamide 6 ◽  
Mechanical Analysis ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Cellulosic Fibers ◽  
The One ◽  
Properties Of Composites

The use of cellulosic fibers from different natural sources as fillers in polymer matrices to improve their properties has been extensively studied in the last years. It is mainly due to the vast availability of natural fibers as well as their biodegradability. The purpose of this present work was to extract cellulose, silica, and cellulose-silica fillers – these last called “hybrids” – from rice husk through delignification and subsequent oxidation and, then, prepare composites with polyamide 6 and improve mainly its thermal-mechanical properties. The content of 10 wt.% of fillers was inserted in PA 6 matrix. Infrared spectroscopy pointed the main characteristic peaks of cellulose and silica of hybrids, as thermogravimetric analysis showed high thermal stability of fillers, allowing their incorporation in PA-6 matrix by extrusion method. Thermo dynamic-mechanical analysis showed, in a general overview, a significant improvement of mechanical properties of composites, as elastic modulus, compared with neat polyamide-6, mainly the one with 2.5 wt% of silica and 7.5% of cellulose. This last also showed increasing of degree of crystallinity, measured by differential scanning calorimetry, showing the extraction efficiency of fillers from rice husk as well as the potential application of composites as structural components in automotive parts.

scholarly journals Synthesis and Properties of Cross-Linkable Waterborne Polyurethane/HMMM-CNT Nanocomposite

Nano Hybrids ◽  
2014 ◽  
Vol 7 ◽  
pp. 87-111
Author(s):  
Mohammad Mizanur Rahman ◽  
M. Nasiruzzaman Shaikh
Keyword(s):  
Mechanical Properties ◽  
Methoxy Group ◽  
Waterborne Polyurethane ◽  
Carboxylic Group ◽  
Acid Salt ◽  
Dsc Analysis ◽  
Scanning Calorimetry ◽  
Methoxy Groups ◽  
Carboxylic Groups ◽  
Carboxylic Acid Salt

A series of cross-linked waterborne polyurethane/hexamethoxymethylmel-amine-carbon nanotube nanocomposites (WBPU/HMMM-CNT) were synthesized using carboxylic group functionalized CNT. The carboxylic groups on CNT were reacted with the methoxy groups of HMMM to get bonded HMMM-CNT. Unreacted methoxy group of HMMM-CNT was crosslinked with the carboxylic acid salt groups of WBPU and made crosslinked WBPU/HMMM-CNT nanocomposite. The mechanical properties (tensile strength and Young’s modulus) of conventional WBPU, crosslinked WBPU/HMMM, WBPU/CNT and WBPU/HMMM-CNT nanocomposites were compared under three conditions: untreated, wet and dried. It was observed that the mechanical properties of the crosslinked WBPU/HMMM-CNT nanocomposites were the least affected by water compared to conventional WBPU, crosslinked WBPU/HMMM, and WBPU/CNT nanocomposites. Differential scanning calorimetry (DSC) analysis also confirmed that the WBPU/HMMM-CNT nanocomposite can absorbed least water which can be easily removed by heating without destroying their crystalline structure. Crosslinked WBPU/HMMM-CNT nanocomposite recovered most of its mechanical properties of (with optimum HMMM-CNT content) after drying.

scholarly journals Reinforcing polypropylene with calcium carbonate of different morphologies and polymorphs

2018 ◽  
Vol 25 (4) ◽  
pp. 745-751 ◽  
Author(s):  
Yanwei Jing ◽  
Xueying Nai ◽  
Li Dang ◽  
Donghai Zhu ◽  
Yabin Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Mechanical Tests ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Crystallization Property ◽  
Reinforced Composite ◽  
Treated Sample ◽  
The Impact

Abstract The influence of calcium carbonate (CaCO3) with different polymorphs (calcite and aragonite) and morphologies (granular and rod-like) on mechanical and crystallization properties of polypropylene (PP) was investigated. Meanwhile, these CaCO3 fillers coated with oleic acid were added in different contents to PP. The results indicate that the tensile strength, flexural strength, modulus, and crystallization property of the filler-treated samples are improved, but the impact strength decreased. The crystallinity of the composites is higher than that of neat PP. Moreover, in the rod shape filler-treated sample, in both whisker species, the mechanical properties of composites are superior to the particles filled. Differential scanning calorimetry, X-ray diffraction, and mechanical tests display that calcite whisker-reinforced composite has higher crystallization enthalpy, melting enthalpy, degree of crystallinity, and mechanical properties than aragonite whiskers and calcite particles filled composites.

scholarly journals Effect of Poling on the Mechanical Properties of β-Poly(Vinylidene Fluoride)

2006 ◽  
Vol 514-516 ◽  
pp. 951-955 ◽  
Author(s):  
Carlos M. Costa ◽  
Vitor Sencadas ◽  
João F. Mano ◽  
Senentxu Lanceros-Méndez
Keyword(s):  
Mechanical Properties ◽  
Mechanical Response ◽  
Vinylidene Fluoride ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Direction Parallel ◽  
Poly Vinylidene Fluoride ◽  
The Stability ◽  
Kinetics Of ◽  
The Degree Of Crystallinity

In this work, mechanical and thermal experimental techniques have been applied in order to relate the mechanical response with the microscopic variations of the material. Stress-strain results along the main directions of β-poly(vinylidene fluoride), β-PVDF, in poled and non-poled samples enables to investigate the influence of the poling process on the mechanical response of the material. Further, differential scanning calorimetry experiments allow the investigation of the effect of poling in the degree of crystallinity of the material as well as on the stability of the crystalline phase. Thermogravimetric analysis was used to investigate the kinetics of the thermal degradation of poled and non-poled β-PVDF samples. The differences observed between the two materials suggest that the poling affects the mechanical properties of the material especially in the direction parallel to the polymeric chains and originates changes at a molecular level that remain beyond the melting of the material.

Hydrodegradation of starch incorporated polylactic acid with acrylic acid as interfacial linker

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Yinghong Xiao ◽  
Jianfei Che ◽  
Anne Bergeret ◽  
Chun Mao ◽  
Jian Shen
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Acrylic Acid ◽  
Polylactic Acid ◽  
Interfacial Adhesion ◽  
Composite Graft ◽  
Dsc Analysis ◽  
Scanning Calorimetry ◽  
Graft Modification ◽  
Scanning Electron

AbstractGraft modification of polylactic acid (PLA) with acrylic acid (AA) using double initiators was studied. The composition of the graft copolymer (PLA-AA) was characterized with Fourier transform infrared (FTIR) spectroscopy and introduction of AA was demonstrated. Differential scanning calorimetry (DSC) analysis indicated that due to the increasing graft efficacy the modified PLA had better interfacial adhesion with starch compared to neat PLA. Fracture surfaces of starch/PLA and starch/PLA-AA were observed using scanning electron microscope (SEM) and the results also demonstrated the better interfacial adhesion of the latter composite. Graft modification of PLA matrix and introduction of starch played important roles in enhancing the mechanical properties (strength and modulus) while remaining good degradability of the composite.

Influence of Single Point Incremental Forming on Mechanical Properties and Chain Orientation in Thermoplastic Polymers

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Mohammad Ali Davarpanah ◽  
Shalu Bansal ◽  
Rajiv Malhotra
Keyword(s):  
Mechanical Properties ◽  
Temperature Rise ◽  
Incremental Forming ◽  
Single Point ◽  
Degree Of Crystallinity ◽  
Single Point Incremental Forming ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Lower Yield Stress ◽  
Chain Orientation

Incremental forming of thermoplastic surfaces has recently received significant interest due to the potential for simultaneous reduction in thermal energy consumption and in part-shape specific tooling. This paper examines the mechanical properties and the chain orientation of the formed material in single point incremental forming (SPIF) of amorphous polyvinyl chloride (PVC) and semicrystalline polyamide sheets. Tensile and stress relaxation properties of the formed polymers are compared to those of the unformed polymer. The effect of incremental depth and tool rotation speed on the above properties, and on the temperature rise of the sheet during SPIF, is quantified. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) are used to compare the chain orientation and crystallinity of the formed and the unformed polymers. It is observed that the formed material has greater toughness and ductility, but lower yield stress and reduced Young's modulus, as compared to the unformed material. We also observe deformation-induced chain reorientation in the formed polymer, with minimal change in the degree of crystallinity. The link between the SPIF process parameters, temperature rise of the polymer during SPIF, change in chain orientation, and change in mechanical properties of the polymer is discussed.

Assessment of a Polyamide Used in Flexible Pipes After Aging in Deoxygenated Water

2020 ◽  
Author(s):  
Danyelle Costa ◽  
Geovanio Oliveira ◽  
Leilane Cirilo ◽  
Marysilvia Costa
Keyword(s):  
Mechanical Properties ◽  
Aging Time ◽  
High Performance ◽  
Accelerated Aging ◽  
Volumetric Analysis ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
Polyamide 12 ◽  
Flexible Pipes ◽  
Indentation Tests

Abstract A high-performance polyamide grade of easy processability which presents excellent thermal and mechanical properties such as resistance to fatigue and creep is studied in this work. An accelerated aging of Polyamide 12 samples was performed in stainless steel autoclaves at 120°C in deoxygenated water at pH 8.7 in order to shorten the aging time and avoid oxidation. The samples were retrieved at distinct aging times which were enough to reach the asymptotic portion of the curve of corrected inherent viscosity (CIV) versus aging time. CIV measurements track modifications of the molecular weight due to hydrolysis. Afterwards, the samples were analyzed through their cross section in the core and edge layer in order to investigate changes due to diffusion effects. Differential scanning calorimetry (DSC) analysis assesses the degree of crystallinity and melting temperature. Thermogravimetric analysis (TGA) was employed in order to investigate changes in the thermal stability and the stage of degradation of the samples. Unlike conventional volumetric analysis techniques, the instrumented indentation tests (IIT) in micro-scale were performed to measure the mechanical properties such as elastic modulus (EIT) and hardness (HIT) along the thickness aiming to detect properties gradient between surface and core. The CIV measurements showed a decrease of 46.3% in the aged sample during the maximum aging time compared to the reference material.

Sign in / Sign up

Export Citation Format

Share Document