Evaluation of the Mechanical Properties of Injection Moulded Hemp Fibre Reinforced Polypropylene Composites

2007 ◽  
Vol 29-30 ◽  
pp. 303-306 ◽  
Author(s):  
G.W. Beckermann ◽  
K.L. Pickering ◽  
N.J. Foreman
Keyword(s):  
Coupling Agent ◽  
Alkali Treatment ◽  
Low Cost ◽  
Tensile Tests ◽  
Single Fibre ◽  
Thermoplastic Composites ◽  
Fibre Strength ◽  
Polypropylene Composites ◽  
Hemp Fibre ◽  
Twin Screw

In recent years, industrial hemp fibre reinforced thermoplastic composites have attracted substantial interest as potential structural materials. These composites have been subject to intense study for use in lightweight, recyclable and low cost applications. The aim of this research was to improve and evaluate the composite tensile strength and fibre/matrix interfacial adhesion by means of fibre treatment and addition of a coupling agent. Hemp fibre was digested in a small pressure vessel with a solution of 5wt% NaOH / 2wt% Na2SO3. Single fibre tensile tests were performed on treated and untreated fibres, and it was found that the alkali treatment resulted in an increase in fibre strength and an improvement in fibre separation. Composites containing either treated or untreated fibre, polypropylene and a maleic anhydride modified polypropylene (MAPP) coupling agent were then compounded in a twin-screw extruder and injection moulded into tensile test specimens. Tensile tests revealed that significant improvements in composite strength were made by using treated fibre and MAPP. The effect of MAPP on the interface of treated hemp fibre/polypropylene composites was assessed by means of the single fibre fragmentation test, and the interfacial shear strength was determined thereafter.

Dynamic Mechanical Properties of Grafted Polypropylene Composites Reinforced with Acetylated Wheat Straw Fibers

2015 ◽  
Vol 1767 ◽  
pp. 139-143
Author(s):  
Ramón Sánchez ◽  
Jacobo Aguilar ◽  
Silvia Y. Martínez ◽  
Reyes J. Sanjuan ◽  
Gerardo A. Mejía ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wheat Straw ◽  
Coupling Agent ◽  
Optical Microscope ◽  
Dynamic Mechanical Properties ◽  
Particle Sizes ◽  
Polypropylene Composites ◽  
Dynamic Mechanical ◽  
Twin Screw ◽  
Composite Pellets

ABSTRACTDynamic mechanical properties of polypropylene (PP) and grafted polypropylene (PP-g-MA) composites reinforced with acetylated wheat straw fibers (WSF) is reported in this work. The materials were prepared with different fiber particle sizes (40, 80 and 140 U.S. mesh) and at different fiber contents (5, 10 and 15 wt.%). The PP and PP-g-MA composites, where anhydride maleic (MA) was used as coupling agent, were obtained using a twin-screw extruder; whereas an injection-molding machine molded the composite pellets into testing specimens. To observe the morphology of the composites, micrographs were taken with an optical microscope. The Dynamic mechanical properties were analyzed using a torsional rheometer. The morphological analysis showed a high porous structure somehow similar to foamed materials. The storage modulus (G′) increased by increasing the fiber content, and decreased with fiber particle sizes for the PP composites. Meanwhile, the use of the coupling agent additive promoted a modulus increase due to higher fiber-polymer interaction, from better adhesion and chemical bonds formation between the fibers-coupling agent-PP.

scholarly journals Laccase-Enzyme Treated Flax Fibre for Use in Natural Fibre Epoxy Composites

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4529
Author(s):  
Hanna M. Brodowsky ◽  
Anne Hennig ◽  
Michael Thomas Müller ◽  
Anett Werner ◽  
Serge Zhandarov ◽  
...  
Keyword(s):  
Coupling Agent ◽  
Interfacial Strength ◽  
Fibre Surface ◽  
Tensile Tests ◽  
Single Fibre ◽  
Natural Fibre ◽  
Flax Fibre ◽  
Specific Strength ◽  
Flax Fibres ◽  
Afm Micrographs

Natural fibres have a high potential as reinforcement of polymer matrices, as they combine a high specific strength and modulus with sustainable production and reasonable prices. Modifying the fibre surface is a common method to increase the adhesion and thereby enhance the mechanical properties of composites. In this study, a novel sustainable surface treatment is presented: the fungal enzyme laccase was utilised with the aim of covalently binding the coupling agent dopamine to flax fibre surfaces. The goal is to improve the interfacial strength towards an epoxy matrix. SEM and AFM micrographs showed that the modification changes the surface morphology, indicating a deposition of dopamine on the surface. Fibre tensile tests, which were performed to check whether the fibre structure was damaged during the treatment, showed that no decrease in tensile strength or modulus occurred. Single fibre pullout tests showed a 30% increase in interfacial shear strength (IFSS) due to the laccase-mediated bonding of the coupling agent dopamine. These results demonstrate that a laccase + dopamine treatment modifies flax fibres sustainably and increases the interfacial strength towards epoxy.

Influence of coupling agent on post-consumption polypropylene composites reinforced with malt bagasse fibers

2021 ◽  
pp. 002199832110370
Author(s):  
Daniela Stefani ◽  
Marcos Aurélio Dahlem Júnior ◽  
Edson Luiz Francisquetti ◽  
Fernando da Silva dos Reis ◽  
Cleide Borsoi ◽  
...  
Keyword(s):  
Coupling Agent ◽  
Interfacial Adhesion ◽  
Morphological Analysis ◽  
Thermoplastic Composites ◽  
Second Step ◽  
Mechanical Resistance ◽  
Brewing Industry ◽  
Polypropylene Composites ◽  
Two Stages ◽  
Reinforcing Filler

The aim of this work was to evaluate the influence of the use of coupling agent (CA) on the properties of thermoplastic composites produced from post-consumer polypropylene (rPP) and malt bagasse fibers (MB) of brewing industry. The CA used was maleic anhydride graft polypropylene copolymer (MAgPP). The study was carried out in two stages: in first step the best concentration of MB fibers was verified, where was varied the fiber contents between 0, 10, 20 and 30% (w/w); in the second step, the best MB concentration evaluated was used with different CA concentrations (0, 1, 3, 5 and 7% w/w). Of the three MB concentrations evaluated as reinforcing filler, the sample with a 30% (w/w) ratio presented 44% lower deformation than the others, presenting better mechanical resistance, although it also presented the highest water absorption. Thus, the 30% MB fiber content was chosen for two step, where the results showed that the PP/MB-30 composite treated with 3% (w/w) CA had a modulus of elasticity 10.3% higher than the same composite without CA, corroborating with the morphological analysis, which indicated better interfacial adhesion between composite components when CA was used. The PP/MB-30 composite treated with 1% (w/w) CA showed the highest thermal stability among all samples.

scholarly journals Effect of Alkali Treatment Using Calcium Hydroxide and the Fiber Length on the Strength of Sugarcane Bagasse Fibers-Polypropylene Composites

2015 ◽  
Vol 815 ◽  
pp. 106-110 ◽  
Author(s):  
Juliana Anggono ◽  
Suwandi Sugondo ◽  
Steven Henrico ◽  
Hariyati Purwaningsih
Keyword(s):  
Calcium Hydroxide ◽  
Fiber Length ◽  
Alkali Treatment ◽  
Low Cost ◽  
Weight Ratio ◽  
Fiber Surface ◽  
Polypropylene Composites ◽  
Original Length ◽  
Sem Study ◽  
Composite Samples

Milling sugarcanes to produce sugar generates by-product called bagasse. Due to the large availability and low cost, the potential of obtaining renewable and biodegradable fibers from bagasse had been explored. To produce fibers from these bagasse, the bagasse was treated in alkali solution using 14 % v/v calcium hydroxide, Ca (OH)2 at high temperature (60-70°C) for 4 hours. After treatment and washed to remove dissolved substances, the fibers were cut into 3 and 5 cm length. Some fibers were prepared in their original length. These fibers were mixed with polypropylene (PP) matrix in weight % ratios of bagasse fibers/PP 20/80, 25/75, and 30/70 and hotpressed to make composite samples. Composites produced were characterised with tensile test to evaluate their tensile properties. Scanning electron microscopy (SEM) was performed on the fiber surface as well as on the fracture area of the tensile tested samples. Tensile strength of the composite shows an increase with the increase of the fiber length and weight % ratios of bagasse fibers/PP up to 25/75 and decreases when bagasse fibers were added to 30 wt.%. The highest strength of 11,30 MPa was obtained when 5 cm fibers were used in a weight % ratio of bagasse fibers/PP at 25/75. SEM study found a greater number of fibers oriented perpendicular to the tension direction.

scholarly journals Mechanical Characterization of Carbon Fibres Recycled by Steam Thermolysis: A Statistical Approach

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
M. Boulanghien ◽  
M. R’Mili ◽  
G. Bernhart ◽  
F. Berthet ◽  
Y. Soudais
Keyword(s):  
Carbon Fibre ◽  
Mechanical Response ◽  
Tensile Tests ◽  
Single Fibre ◽  
Resin Matrix ◽  
Fibre Strength ◽  
Carbon Fibres ◽  
Statistical Parameters ◽  
Residual Properties ◽  
Steam Thermolysis

The recent development of technologies for recycling carbon fibre reinforced plastics (CFRPs) leads to the need to evaluate the mechanical response of recycled carbon fibres. As these fibres are likely to be degraded during the recycling treatment, it is very important to determine their tensile residual properties so as to evaluate their ability as reinforcement for new composite materials. Carbon fibres reclaimed by a steam-thermal treatment applied to degrade the epoxy resin matrix of a CFRP are here analysed. Two conditions were chosen so as to reach two degradation efficiency levels of the steam thermolysis. Several carbon fibre samples were selected for mechanical testing carried out either on single filaments using single fibre tensile tests or on fibre tows using bundle tensile tests. It is shown that the single fibre tensile test leads to a wide variability of statistical parameters derived from the analysis. Bundle tensile tests results were able to indicate that fibre strength of recycled carbon fibre is similar to corresponding as-received carbon fibres thanks to a statistically relevant database. Wide number of tested filaments enabled indeed to obtain low scatters.

scholarly journals STUDY OF THE EFFECT OF CHEMICAL TREATMENTS ON THE TENSILE BEHAVIOUR OF ABACA FIBER REINFORCED POLYPROPYLENE COMPOSITES

2014 ◽  
Vol 10 (6) ◽  
pp. 2814-2822
Author(s):  
Ramadevi Punyamurthy ◽  
Dhanalakshmi Sampathkumar ◽  
Basavaraju Bennehalli ◽  
Pramod V Badyankal
Keyword(s):  
Tensile Strength ◽  
Alkali Treatment ◽  
Tensile Tests ◽  
Tensile Behaviour ◽  
Fiber Reinforced ◽  
Compression Moulding ◽  
Polypropylene Composites ◽  
Chemical Treatments ◽  
Chloride Treatment ◽  
Benzene Diazonium

Abaca fibers were subjected to different chemical treatments like alkali treatment, permanganate treatment, acrylation & benzene diazonium chloride treatment and these chemically treated fibers were used as reinforcements in the preparation of polypropylene composites by hot compression moulding method. Various composites were fabricated with different fiber loadings of 20%, 30%, 40%, 50%, 60%, and 70%. Abaca composites with 40% fiber loadings were found to have optimum properties when tensile tests were carried out and the study also revealed that treated composites were found to have improved tensile properties when compared to untreated composites. Among all the treatments carried out benzene diazonium chloride treated abaca fiber reinforced polypropylene composites showed higher tensile strength. These composites showed 82.38% increase in tensile strength when compared to untreated composites for 40% fiber loading. 

scholarly journals Characterization of textile-grade carbon fiber polypropylene composites

2020 ◽  
pp. 096739112093010 ◽  
Author(s):  
Pritesh Yeole ◽  
Shailesh Alwekar ◽  
N Krishnan P Veluswamy ◽  
Surbhi Kore ◽  
Nitilaksha Hiremath ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Low Cost ◽  
Length Distribution ◽  
Thermal Characterization ◽  
Polypropylene Composites ◽  
Fiber Length Distribution ◽  
Twin Screw ◽  
Good Potential ◽  
The Impact

In this work, we consider low-cost carbon fiber produced with a textile-grade precursor. The objective of the study is to investigate textile-grade carbon-fiber-reinforced-polypropylene composites (TCF-PP) from compounded pellets for mechanical and thermal characterization. Four sets of pellets with 1%, 5%, 10%, and 15% reinforcement were manufactured using textile-grade carbon fiber (TCF) and polypropylene (PP) by twin-screw compounding. The addition of TCFs through gravimetric feeder directly in the extruder resulted in lower fiber content; however, side feeder has shown good potential. The pellets were further processed in extrusion compression molding to manufacture plaques. An increase in fiber loading has a negligible effect on fiber attrition as fiber length distribution variation between 1% and 15% reinforced pellets was very small. The addition of TCFs in PP showed a significant improvement in mechanical properties. The tensile strength and modulus of the composite were 26% and 161%, respectively, improved by the addition of 10 wt% TCF. Similar results were observed in the flexure test. However, the impact properties were reduced by 25.54% by the addition of 15% TCF.

scholarly journals Effect of Reinforcement on Tensile Behavior of MWCNT Filled Thermoplastic Composites

2020 ◽  
Vol 22 (12) ◽  
Author(s):  
Shrinatha R Katti ◽  
◽  
V. Achutha M ◽  
K. Sridhara B ◽  
◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Theoretical Data ◽  
Tensile Tests ◽  
Extrusion Process ◽  
Thermoplastic Composites ◽  
Multiwalled Carbon ◽  
Twin Screw ◽  
Moulding Machine ◽  
Engineering Polymers

Polypropylene (PP) is one of the most widely used engineering polymers. In this study, multiwalled carbon nanotube (MWCNT) and carbon Nanopowder (CNP) were melt blended into PP in the different ratios for two different set of composites. For first set 2.5, 5 and 10 wt.% was mixed using twin screw extrusion process. The extruded pellets were then injection moulded using a 50 Ton injection moulding machine to produce PP+MWCNT composite flattest specimens according to ASTM standards and were used to carry out the tensile tests. While there is a reduction in failure strain and a marginal increase in ultimate tensile strength, there is nearly 65 % increase in young’s modulus with MWCNT as reinforcement. These experimental values were compared with the theoretical values calculated using Halpin-Tsai model for randomly oriented fibres.There was significant deviationof the theoretical data from the experimental data. The comparison and analysis of theoretical and experimental results are carried out in the present work. A mathematical model equation has been fit for the variation of young’s modulus in both the sets of composites. The variation has been found to be constant in terms of the parameters of the equation. This shows the variation of the tensile properties are proportional to the degree of reinforcement.

Morphology, mechanical, and crystallization behaviors of micro- and nano-ZnO filled polypropylene composites

2012 ◽  
Vol 31 (5) ◽  
pp. 323-329 ◽  
Author(s):  
Haydar U. Zaman ◽  
Park Deuk Hun ◽  
Ruhul A. Khan ◽  
Keun-Byoung Yoon
Keyword(s):  
Tensile Strength ◽  
Interfacial Adhesion ◽  
Tensile Modulus ◽  
Tensile Tests ◽  
Interfacial Interaction ◽  
Screw Extruder ◽  
Polypropylene Composites ◽  
Crystallization Behaviors ◽  
The Matrix ◽  
Twin Screw

The aim of this study was to study the effect of ZnO concentration on the morphology, mechanical, and crystallization behaviors of iPP. Three compositions of iPP/mZnO and iPP/nZnO composites were prepared in a co-rotational twin-screw extruder machine with ZnO content of 2 wt%, 5 wt%, and 8 wt%. Tensile tests showed that the tensile strength at yield and tensile modulus of the composites tended to increase with increasing contents of mZnO/nZnO particles. This improvement in the tensile properties was attributed to good interfacial adhesion between the fillers and the matrix, as evidenced by TEM examination. The tensile strength at yield and tensile modulus values of iPP/nZnO composite with the addition of 2–8 wt% nZnO are higher than those of virgin iPP, and even higher than those of iPP/mZnO composite with the addition of 2–8 wt% mZnO. The non-isothermal crystallization behavior of iPP/mZnO and iPP/nZnO composites was investigated using DSC. The results indicated that the interfacial interaction between iPP and mZnO/nZnO increased the crystallization temperature when the content of ZnO is 5 wt%.

scholarly journals Intrinsic tensile properties of cocoon silk fibres can be estimated by removing flaws through repeated tensile tests

2015 ◽  
Vol 12 (107) ◽  
pp. 20150177 ◽  
Author(s):  
Rangam Rajkhowa ◽  
Jasjeet Kaur ◽  
Xungai Wang ◽  
Warren Batchelor
Keyword(s):  
High Performance ◽  
Spider Silk ◽  
Failure Load ◽  
Tensile Tests ◽  
Single Fibre ◽  
Fibre Strength ◽  
Fracture Test ◽  
Final Test ◽  
Lower Strength ◽  
Composite Curve

Silk fibres from silkworm cocoons have lower strength than spider silk and have received less attention as a source of high-performance fibres. In this work, we have used an innovative procedure to eliminate the flaws gradually of a single fibre specimen by retesting the unbroken portion of the fibre, after each fracture test. This was done multiple times so that the final test may provide the intrinsic fibre strength. During each retest, the fibre specimen began to yield once the failure load of the preceding test was exceeded. For each fibre specimen, a composite curve was constructed from multiple tests. The composite curves and analysis show that strengths of mass-produced Muga and Eri cocoon silk fibres increased from 446 to 618 MPa and from 337 to 452 MPa, respectively. Similarly, their toughness increased from 84 to 136 MJ m −3 and from 61 to 104 MJ m −3 , respectively. Composite plots produced significantly less inter-specimen variations compared to values from single tests. The fibres with reduced flaws as a result of retests in the tested section have a tensile strength and toughness comparable to naturally spun dragline spider silk with a reported strength of 574 MPa and toughness of 91–158 MJ m −3 , which is used as a benchmark for developing high-performance fibres. This retesting approach is likely to provide useful insights into discrete flaw distributions and intrinsic mechanical properties of other fatigue-resistant materials.

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