Preparation and Study of Flexural Strength and Impact Strength for Hybrid Composite Materials used in Structural Applications

2020 ◽  
Vol 38 (8A) ◽  
pp. 1117-1125
Author(s):  
Teeb A. Mohameed ◽  
Sihama I. Salih ◽  
Wafaa M. Salih

 Many of the polymeric materials used for structural purposes have weak mechanical properties, these characteristics can therefore be improved by preparing a hybrid laminar composite. In this work use melting mixing method using screw extruder to prepare sheets of polymer blends and nanocomposites based on polymer blends, and using a hot hydraulic press machine to prepared hybrid laminates composites. Two groups of hybrid laminar composites were prepared, the first group is consist of [((94%PP: 5%PMMA: 1 %( PP-g-MA)): 0.3% ZrO2): 6%KF and 8%KF] and the second group is [((94%PP: 5%UHMWPE: 1 %( PP-g-MA)): 0.3% ZrO2): 6%KF and 8%KF]. The results illustrated the impact strength and fracture toughness are increase with increased weight percentage of Kevlar fiber in for both groups of laminar composites and the highest values for two groups are (58.1, 54.95 KJ/M2) and (8.4, 9.16 MPa√m) respectively, any that, at the rate of increment reached to (120.4%, 107%) and (52.7%, 66.5%) respectively, compared with the neat PP. Moreover, the flexural strength values of the first group samples of hybrid laminar composite remained constant, when added kevlar fiber to nanocomposite. While, the flexural strength values of the second group samples of hybrid laminar composite increase with increase the ratio of kevlar fiber in composite to reach the maximum values (92 MPa) at 8% wt. of kevlar fiber, any, at the rate of increment reached to 39.4% compared with the neat PP. As well as, the results shown that the flexural properties and fracture toughness of the second group samples higher than they are for the first group samples.

Author(s):  
Zahid Iqbal Khan ◽  
Zurina Binti Mohamad ◽  
Abdul Razak Bin Rahmat ◽  
Unsia Habib ◽  
Nur Amira Sahirah Binti Abdullah

This work explores a novel blend of recycled polyethylene terephthalate/polyamide 11 (rPET/PA11). The blend of rPET/PA11 was introduced to enhance the mechanical properties of rPET at various ratios. The work’s main advantage was to utilize rPET in thermoplastic form for various applications. Three different ratios, i.e. 10, 20 and 30 wt.% of PA11 blend samples, were prepared using a twin-screw extruder and injection moulding machine. The mechanical properties were examined in terms of tensile, flexural and impact strength. The tensile strength of rPET was improved more than 50%, while the increase in tensile strain was observed 42.5% with the addition of 20 wt.% of PA11. The improved properties of the blend were also confirmed by the flexural strength of the blends. The flexural strength was increased from 27.9 MPa to 48 MPa with the addition of 30 wt.% PA11. The flexural strain of rPET was found to be 1.1%. However, with the addition of 10, 20 and 30 wt.% of PA11, the flexural strain was noticed as 1.7, 2.1, and 3.9% respectively. The impact strength of rPET/PA11 at 20 wt.% PA11 was upsurged from 110.53 to 147.12 J/m. Scanning electron microscopy analysis revealed a dispersed PA11 domain in a continuous rPET matrix morphology of the blends. This work practical implication would lead to utilization of rPET in automobile, packaging, and various industries.


Author(s):  
Dr. Pratik Bhatnagar

Aim: To assess and compare the impact of reinforcement of PMMA with glass fibre, polyethylene fibre and carbon fibres on flexural strength, fracture toughness and abrasive resistance. Background: In view of inadequate mechanical and physical characteristics of PMMA which include low impact strength and low surface hardness and resulting lowered clinical performance of the prosthesis, the study was designed to investigate the impact of reinforcement of PMMA with glass, polyethylene and carbon fibers on flexural strength, fracture toughness and abrasive resistance. Methods and Findings: Rectangular specimens (n=120; 30 each from 4 groups; 65 × 10 × 3.3 mm3) were fabricated and loaded on Universal Testing Machine until fracture for flexural strength and fracture toughness and on Taber Abrasive Tester for abrasive resistance. Data were analyzed using one–way ANOVA followed by Post Hoc test - Bonferroni multiple comparison analysis, using significance level of 0.05. Significant increase in fracture toughness was observed in specimens reinforced with polyethylene and carbon fiber, albeit the values of flexural strength were increased insignificantly. Specimens reinforced with glass and carbon fiber had significantly low values of abrasive resistance. Conclusion: Findings indicate that reinforcement of PMMA by non-specific fibers like glass, polyethylene and carbon resulted in significant increase in fracture toughness and decrease in abrasive resistance.


2011 ◽  
Vol 55-57 ◽  
pp. 447-450 ◽  
Author(s):  
Jian Li ◽  
Zheng Qun Huang ◽  
Yan Qin

In this article, a kind of SMC artificial marble was prepared. In order to enhance the mechanical properties and prolong the using life of SMC artificial marble, some effects such as fiber content, filler content and molding temperature etc. on the mechanical properties were carefully studied, too. Results showed that the increase of fiber content could improve the impact strength of SMC artificial marble when the fiber length was 10mm and the increase of filler content would decrease the flexural strength of SMC artificial marble. And the molding temperature at the range of 130°C ~ 160°C had little influence on the mechanical properties of SMC artificial marble. Comparing with natural marble and casting marble, SMC artificial marble owed superior overall performance and it was much more suitable for industry production.


2011 ◽  
Vol 236-238 ◽  
pp. 1725-1730 ◽  
Author(s):  
Wei Jen Chen ◽  
Ming Yuan Shen ◽  
Yi Luen Li ◽  
Chin Lung Chiang ◽  
Ming Chuen Yip

This study used carbon aerogels (CA) and phenolic resin in fixed proportations to produce nano high polymer resin, and used poly ehtylene oxide (PEO) as the modifying agent for phenolic resin to improve the mechanical properties of phenolic resin and promote the surface conductivity. The prepared nano high polymer resin and carbon cloth were made into nano-prepreg by using ultrasonic impregnation method, and a nano-prepreg composite material was prepared by using hot compacting and cut to test pieces to measure its mechanical properties and surface conductivity as well as the influence of temperature-humidity environment (85°C/168hr and 85°C/85%RH/168hr) on mechanical properties. The result showed that the surface conductivity increased by 64.55%, the tensile strength at room temperature increased by 35.7%, the flexural strength increased by 18.4%, and the impact strength increased by 101%. In hot environment (85°C/168hr), the tensile strength decreased by 23.8%, the flexural strength increased by 3.1%, and the impact strength increased by 84.6%. In high temperature-high humidity environment (85°C/85% RH/168hr), the tensile strength decreased by 29.6%, the flexural strength decreased by 17%, and the impact strength increased by 95.7%.Introduction


2017 ◽  
Author(s):  
Yu. N. Saraev ◽  
S. V. Gladkovsky ◽  
S. V. Lepikhin ◽  
D. A. Dvoynikov ◽  
I. S. Kamantsev ◽  
...  

2009 ◽  
Vol 20 (2) ◽  
pp. 132-137 ◽  
Author(s):  
Rafael Leonardo Xediek Consani ◽  
Douglas Duenhas de Azevedo ◽  
Marcelo Ferraz Mesquita ◽  
Wilson Batista Mendes ◽  
Paulo César Saquy

The present study evaluated the effect of repeated simulated microwave disinfection on physical and mechanical properties of Clássico, Onda-Cryl and QC-20 denture base acrylic resins. Aluminum patterns were included in metallic or plastic flasks with dental stone following the traditional packing method. The powder/liquid mixing ratio was established according to the manufacturer's instructions. After water-bath polymerization at 74ºC for 9 h, boiling water for 20 min or microwave energy at 900 W for 10 min, the specimens were deflasked after flask cooling and finished. Each specimen was immersed in 150 mL of distilled water and underwent 5 disinfection cycles in a microwave oven set at 650 W for 3 min. Non-disinfected and disinfected specimens were subjected to the following tets: Knoop hardness test was performed with 25 g load for 10 s, impact strength test was done using the Charpy system with 40 kpcm, and 3-point bending test (flexural strength) was performed at a crosshead speed of 0.5 mm/min until fracture. Data were analyzed statistically by ANOVA and Tukey's test (α= 0.05%). Repeated simulated microwave disinfections decreased the Knoop hardness of Clássico and Onda-Cryl resins and had no effect on the impact strength of QC-20. The flexural strength was similar for all tested resins.


2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Retno Eka Pramitasari ◽  
Mochamad Arif Irfa'i ◽  
Reza Prasetyo

The development of increasingly advanced technology, especially in the health sector, can lead to an increase in the need for composite materials used. This study aims to describe the results of the concentration of KOH solution and the orientation of the ramie fiber on the impact strength of composites with a polyester matrix. This research is an experimental study with the manipulation variables are the concentration of the KOH solution and the orientation of the fiber direction by determining the value of the impact strength as the dependent variable of ramie fiber as a control variable of this study. This study obtained the optimum impact test result of 0.0711 J/mm2 with 5% KOH solution concentration and located at 0o/45o/90o fiber direction orientation. While the results of the lowest impact test resulted in a value of 0.0101 J/mm2 without soaking the KOH solution and located at 90o/0o/90o fiber direction orientation.


2020 ◽  
pp. 152808372093222
Author(s):  
S Navid Hosseini Abbandanak ◽  
Mehdi Abdollahi Azghan ◽  
Amin Zamani ◽  
Mehrdad Fallahnejad ◽  
Reza Eslami-Farsani ◽  
...  

The remarkable resurgence of fiber metal laminates (FMLs) is certainly attributed to the hybrid properties inherent to light metals and fibers reinforced polymer (FRP). There are few reports on the role of nano-size reinforcements in these composites. In this study, the effect of graphene nanoplatelets (GNPs) on the flexural and Charpy impact properties of FMLs of aluminum (Al) 2024 reinforced with hybrid glass/Kevlar fibers-epoxy was investigated. Different wt.% of GNPs (0.0, 0.1, 0.25 and 0.5) and hand lay-up method were used to fabricate nano-FMLs followed by evaluating them in three-point bend and Charpy impact tests. Before making the FMLs, the surfaces of Al sheets were modified to generate surface pores/nano-pores in order to improve the interfacial bonding within the FMLs layers. The FMLs containing 0.1 wt.% GNPs exhibited 10%, 9% and 11% improvement in flexural strength and modulus and impact strength, respectively, compared to the FMLs containing 0.0 wt.% GNPs. Increase of the GNPs to 0.25 wt.% caused a reduction of the flexural strength and modulus and impact strength values; 13.7%, 3% and 25.5% compared to the samples without GNPs. Also increase of the GNPs to 0.5 wt.% decreased these properties to 31.3%, 8.8% and 29.5%. Scanning electron microscopy (SEM) observations of their fracture surfaces showed better adhesion at both polymer/fibers (within the FRP) and Al/FRP interfaces. However, at higher wt.% of GNPs, the FMLs became weaker and more brittle. Agglomerated GNPs at the Al/FRP interface penetrated/filled the surface pores/nano-pores on the Al surfaces. Therefore prevent the polymer penetration in pores, resulting in weak interfacial bond and thus overall weaker and less ductile FMLs. As a result, the Charpy impact values for the 0.25 and 0.5 wt.% GNPs samples were respectively 33 and 37 percent smaller than that for the 0.1 wt.% GNPs sample.


2005 ◽  
Vol 13 (4) ◽  
pp. 403-413
Author(s):  
Shanhua Zhou ◽  
Zhiyu Xu ◽  
Xin Liu ◽  
Yan Gao ◽  
Qingzhi Dong

A new interfacial modifier made of tetradecyl methylacrylate-maleic anhydride copolymer (TMA- co-MAH) was prepared and characterized. The effect of reaction time and monomer ratio on the gross conversion and MAH content in the copolymer was studied. When the glass mat was treated with TMA- co-MAH solutions and compounded with PP, the MAH group of the interfacial modifier formed strong interactions with the glass mat and the long side chain of the interfacial modifier entangled firmly with the polypropylene matrix. In comparison with maleated polyolefins, the higher MAH content of the TMA- co-MAH resulted in better interfacial adhesion between the PP and the glass mat resulting in increased flexural strength and modulus, and the ductility of the TMA- co-MAH introduced a ductile interlayer into the interface of the glass mat reinforced polypropylene composites (GMT-PPs) to achieve higher impact strength. Therefore the mechanical properties of composites treated with TMA- co-MAH were all superior to those of GMT-PPs treated with maleic anhydride grafted polypropylene (PP- g-MAH) solutions when they were used at the same level. The effects of anhydride content, concentration of copolymer and compounding time on the mechanical property of GMT-PPs were investigated. With the optimal monomer ratio, MAH:TMA = 7:3, a 3% copolymer solution and a compounding time of 5 min, the impact strength, flexural strength and modulus of GMT-PPs treated with the new interfacial modifier were all improved significantly compared with composites treated with 0.3% PP- g-MAH solution.


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