scholarly journals Use of Organic Acids in Bamboo Fiber-Reinforced Polypropylene Composites: Mechanical Properties and Interfacial Morphology

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2007
Author(s):  
Lety del Pilar Fajardo Cabrera de Lima ◽  
Cristian David Chamorro Rodríguez ◽  
José Herminsul Mina Hernandez

In obtaining wood polymer composites (WPCs), a weak interfacial bonding can cause problems during the processing and affect the mechanical properties of the resulting composites. A coupling agent (CA) is commonly used to solving this limitation. To improve the interfacial bonding between bamboo fiber (BF) and a polypropylene matrix, the effect of three organic acids on the mechanical properties and interfacial morphology were investigated. The BF/PP composites were prepared in five families: the first without CA, the second using a maleic anhydride-grafted polypropylene coupling agent, and the third, fourth, and fifth families with the addition of organic acids (OA) tricarboxylic acid (TRIA), hexadecanoic acid (HEXA), and dodecanoic acid (DODA), respectively. The use of OA in BF/PP improved the interfacial adhesion with the PP matrix, and it results in better mechanical performance than composites without CA. Composites coupled with MAPP, TRIA, DODA, and HEXA showed an increase in Young’s modulus of about 26%, 23%, 15%, and 16% respectively compared to the composite without CA incorporation. In tensile strength, the increase in composites with CA was about 190%, while in the flexural modulus, the coupled composites showed higher values, and the increase was more in composites with TRIA: about 46%. The improvement caused by tricarboxylic acid was similar to that promoted by the addition of maleic anhydride-grafted polypropylene (MAPP).


2017 ◽  
Vol 25 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Jiuqiang Song ◽  
Yan Qin ◽  
Jia Chen ◽  
Siwen Qin

In this paper, a continuous glass fiber-reinforced polypropylene prepreg was prepared by fiber treatment with a silane coupling agent and MAH-g-PP resin. Continuous glass fiber-reinforced polypropylene sheets were made from prepreg and PP mats by hot-pressing; they displayed exceptional performance. This paper studies the effects of maleic anhydride grafting on the polypropylene crystallinity and MAH-g-PP content in the prepreg, and the mechanical properties of the composites. The results showed that modifying PP with maleic anhydride decreased the tacticity of the polypropylene molecular chain, which reduced the crystallinity and melting point. An excellent interface formed between the polypropylene and fiber after the glass fiber was treated with a silane coupling agent and MAH-g-PP resin. The mechanical properties of the polymer materials displayed more favorable properties as MAH-g-PP content increased; the ideal MAH-g-PP content was 50%.



Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 226 ◽  
Author(s):  
Ze Kan ◽  
Hao Shi ◽  
Erying Zhao ◽  
Hui Wang

Anionic polyamide-6 (APA-6) composites are prepared by the VARIM process using different modified ramie fabrics to study the structure and properties of different composites. This study can not only evaluate the optimal modification method for the ramie fabrics, but also further explore the interface interaction mechanism between ramie fabrics and APA-6. In this article, the ramie fabrics are modified by a pretreatment, coupling agent and alkali modification. Different modification methods have different effects on the structure, surface properties and mechanical properties of ramie fabrics, which will further affect the impregnation process, interfacial and mechanical properties of the composites. Through the performance analysis of different modified ramie fabrics reinforced APA-6 composites, the conversion, crystallinity and molecular weight of these composites are at a high level, which indicate that the polymerization of these composites is well controlled. The coupling agent modified ramie fabrics composites and the pretreated ramie fabrics composites have higher flexural modulus, tensile strength and dynamic mechanical properties. Alkali-modified ramie fabrics composites have slightly lower mechanical properties, which however have the highest interlaminar shear strength and outperformed interface properties of the composites.



Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1459
Author(s):  
Agbelenko Koffi ◽  
Fayçal Mijiyawa ◽  
Demagna Koffi ◽  
Fouad Erchiqui ◽  
Lotfi Toubal

Wood–plastic composites have emerged and represent an alternative to conventional composites reinforced with synthetic carbon fiber or glass fiber–polymer. A wide variety of wood fibers are used in WPCs including birch fiber. Birch is a common hardwood tree that grows in cool areas such as the province of Quebec, Canada. The effect of the filler proportion on the mechanical properties, wettability, and thermal degradation of high-density polyethylene/birch fiber composite was studied. High-density polyethylene, birch fiber and maleic anhydride polyethylene as coupling agent were mixed and pressed to obtain test specimens. Tensile and flexural tests, scanning electron microscopy, dynamic mechanical analysis, differential scanning calorimetry, thermogravimetry analysis and surface energy measurement were carried out. The tensile elastic modulus increased by 210% as the fiber content reached 50% by weight while the flexural modulus increased by 236%. The water droplet contact angle always exceeded 90°, meaning that the material remained hydrophobic. The thermal decomposition mass loss increased proportional with the percentage of fiber, which degraded at a lower temperature than the HDPE did. Both the storage modulus and the loss modulus increased with the proportion of fiber. Based on differential scanning calorimetry, neither the fiber proportion nor the coupling agent proportion affected the material melting temperature.



2011 ◽  
Vol 471-472 ◽  
pp. 898-903 ◽  
Author(s):  
Ahmad Ramli Rashidi ◽  
Uzir Wahit Mat ◽  
R.A. Abdullah

For many years, research was focused on developing a medical part of human body from polymer as to replace metal. In this study, the aim is to produce a Polyetheretherketone/Hydroxyapatite (PEEK/HA) composite which posses balance mechanical properties and good spreading of bioactive ceramic, hydroxyapatite. The composite consist of 10-30 wt% HA were compounded via nano-single screw extruder and sample for testing were produced by injection molding. Each formulation of HA was treated with (3-Aminopropyl)trimethoxysilanes coupling agent to compare with untreated HA. The result showed that the slight increasing value of Elastic modulus, flexural strength, tensile strength while decreasing flexural modulus for 10 and 20 wt% HA compared to untreated composite. The enhance of bioactivity has been proven with the incorporation of HA into PEEK. SEM-EDX image showed the bulk formation of apatite layers on the composite surface with 30 wt% HA after 3 days immersed in SBF solution. Finally, these composite be capable of being one of the biomedical part seing as the mechanical properties were found to be within the properties of human cortical and cancellous bone.



2015 ◽  
Vol 1134 ◽  
pp. 178-184
Author(s):  
Siti Nurai'syah Umar Shaifudin ◽  
Dzaraini Kamarun ◽  
Nur Hikamah Seth ◽  
Engku Zaharah Engku Zawawi

Matured luffa fibers can be used as reinforcing fillers for polymers to produce industrial products. Frequently, these fibers are incorporated in thermoplastics and thermosets binders at low loadings (1 – 40) wt % of total composition. In this project, high loadings of luffa fiber (50 to 70 wt %) were incorporated with polypropylene (PP), coupling agent maleic anhydride grafted polypropylene (MAPP) and Cloisite 15A using extrusion for compounding. (C15A) at 5 wt % was added for reinforcement and to increase density of compounded materials for ease of processing during mixing. The compounded material was pelletized and the test pieces were prepared using compression moulding and shaped according to the standard. The effects of fiber loadings on the mechanical properties of the composites were determined.



2012 ◽  
Vol 729 ◽  
pp. 216-221 ◽  
Author(s):  
Hajnalka Hargitai ◽  
Tamás Ibriksz ◽  
János Stifter ◽  
Endre Andersen

In our experiments polyamide 6/high density polyethylene blends (25/75 wt%) were produced and maleic anhydride grafted polyethylene was used as chemical coupling agent. To get finer microstructure and enhance the mechanical properties the blends were compounded by different nanostructured reinforcements. Two kinds of nanosilicate, the layered structure montmorillonite and the needle like sepiolite were applied in different concentrations and their effect on the mechanical and melting properties were examined.



2021 ◽  
Vol 36 (5) ◽  
pp. 545-556
Author(s):  
A. Hamza ◽  
R. K. Arya ◽  
A. D. Palsodkar ◽  
G. R. Bhadu ◽  
S. J. A. Rizvi

Abstract Isotactic polypropylene (iPP) was nucleated in-situ with calcium pimelate during melt compounding. Calcium pimelate is a highly effective β-nucleator for isotactic polypropylene (iPP). The β-nucleated iPP was characterized by wide angle x-ray diffraction (WAXD) and differential scanning calorimetry (DSC) for its crystallinity and crystal structure. In addition, the injection-molded samples were tested for thermo-mechanical properties. It is found that very low quantity (< 0.1 wt. %) of β-nucleator is required to produce sufficiently high β-crystal fraction (Kβ) in isotactic polypropylene. β-nucleated iPP shows increment of 11 to 14 °C in its heat deflection temperature (HDT). It was also observed that slow cooling rate of β-nucleated iPP promotes the formation of β-crystals and that tensile stretching leads to complete transformation of β crystals into a-crystals at room temperature. It was also revealed that the presence of maleic anhydride grafted polypropylene (PP-g-MA), a well-known coupling agent (or compatibilizer), may reduce the (Kβ) value to a marginal extent. It was also observed that the thermo-mechanical properties were not much affected by the presence of PP-g-MA. Therefore, calcium pimelate may be used as β-nucleator in case of neat as well as reinforced polypropylene containing maleic anhydride as coupling agent.



2013 ◽  
Vol 812 ◽  
pp. 187-191 ◽  
Author(s):  
Nur Izzati Zulkifli ◽  
Noorasikin Samat

Recycled polypropylene/microcrystalline cellulose (rPP/MCC) composites were prepared by adding different loadings of maleic anhydride grafted polypropylene (MAPP) coupling agent. The tensile, impact and morphological properties of the composites were investigated. The obtained results show that the tensile and impact strengths of the composites were significantly enhanced with the addition of MAPP loading from 2 to 5 wt%, as compared with unfilled rPP/MCC composites. However, it was found that at low filler content, different amounts of MAPP resulted in no appreciable change in the tensile strength and modulus. Moreover, dynamic mechanical analysis (DMA) results indicated that, increasing the amount of MAPP loading from 2 to 5 wt% in rPP/MCC provide better stiffness of the composite compared to those neat rPP and neat PP. Field emission scanning microscopy (FESEM) has shown that the composite, with MAPP loading, promotes better fibermatrix interaction.



2013 ◽  
Vol 812 ◽  
pp. 241-245 ◽  
Author(s):  
Fatimah A’thiyah Sabaruddin ◽  
Noorasikin Samat

Polymer nanocomposites containing polypropylene (PP) as the polymer matrix and nanofiller aluminium hydroxide (ATH) as the flame retardant filler were compounded with various loading of maleic anhydride grafted polypropylene, MAPP (0, 1, 2, 3, 5 wt %). All materials were mixed using melt mixing process and were further prepared using an injection moulding machine. The mechanical performances of the samples were characterized using tensile and impact tests. Improvements were observed for the tensile and impact properties of the PP/ATH samples after being loaded with MAPP. MAPP loading of 1 wt % was determined to be the optimum content of coupling agent addition as this loading enabled the best performance of the nanocomposite in tensile and impact tests. Different morphologies of the fracture surfaces for all samples were characterized using FESEM analysis.



2014 ◽  
Vol 695 ◽  
pp. 273-276 ◽  
Author(s):  
Nor Nisa Balqis Mohammad ◽  
Agus Arsad ◽  
Abdul Razak Rahmat ◽  
S.Z. Mat Des ◽  
Nur Syazana Abdullah Sani

Polylactic acid (PLA)/ Natural rubber (NR) in the presence of PLA grafted Maleic Anhydride (PLAGMA) as compatibilizer was prepared by the melting blend method. In attempt to achieve high performance of the blend, nanocomposites were formed by incorporating different ratio of carbon nanotube (CNT) in PLA/NR/PLAGMA blend. The effect of CNT content on mechanical properties was investigated. With increasing CNT content, Young’s modulus and flexural modulus were increased firstly and then decreased as CNT was further added. In other hand, impact strength was dropped as expected as the CNT loading was increased.



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