Effects of fiber-surface modification on the properties of bamboo flour/polypropylene composites and their interfacial compatibility

2018 ◽  
Vol 38 (2) ◽  
pp. 157-166 ◽  
Author(s):  
Jian Wang ◽  
Jie Dong ◽  
Jianwei Zhang ◽  
Baodong Zhu ◽  
Dongling Cui

Abstract This work aimed to study the effects of different surface treatments on the morphologies and thermo-mechanical properties of the bamboo flour/polypropylene (BF/PP) composites, which were prepared by melt blending with 15 wt% of filler load. The BF was first pretreated with 10 wt% sodium hydroxide (NaOH) solutions for 4 h, after which the pre-treated BF was modified by stearic acid and silane. The chemical structure of the treated BF fibers was characterized through Fourier transform infrared spectroscopy (FTIR), and the results showed that alkali treatment efficiently removed hemicellulose, lignin, and pectin. Moreover, stearic acid and silane were successfully introduced to the BF surface through chemical bonding. The changes in heat stability of BF investigated by thermogravimetric analysis (TGA) revealed that the presence of treatment contributes to a better thermal stability for BF fibers. In addition, the scanning electron microscopy (SEM) observation of BF/PP composites displayed not only better dispersion of treated-BF in the polypropylene (PP) matrix, but also improved fiber-matrix interfacial compatibility, especially when silane treatment was used. Accordingly, the mechanical properties improved significantly in the presence of treated-BF.

2013 ◽  
Vol 13 (1) ◽  
pp. 95-100 ◽  
Author(s):  
Netra L Bhandari ◽  
Sabu Thomas ◽  
Chapal K Das ◽  
Rameshwar Adhikari

In this paper, the bamboo flour (BF) reinforced polypropylene (PP) composites were studied with special attention to morphology of the composites and the effectiveness of chemically modified fillers to improve their mechanical properties. The composites of polypropylene with neat bamboo flour (BF) and treated bamboo flour (TBF) in different proportions were prepared by melt mixing followed by compression molding. The samples were characterized by Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), tensile testing and water absorption testing. The results show that the alkali treated BF is compatible with polypropylene matrix than the neat one as the effects are reflected in the morphological features of the composites and their tensile mechanical properties. Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 95-100 DOI: http://dx.doi.org/10.3126/njst.v13i1.7447


2011 ◽  
Vol 410 ◽  
pp. 47-50 ◽  
Author(s):  
Wichuda Chanprapanon ◽  
Nitinat Suppakarn ◽  
Kasama Jarukumjorn

Composites based on polypropylene (PP) and sisal fiber (SF) were prepared by melt blending. Sisal fiber content was 30 phr. Organoclay (OMMT; Cloisite®30B) (1-7 phr) was incorporated into the composites. In addition, maleic anhydride grafted polypropylene (MAPP) was used as a compatibilizer to enhance the interfacial adhesion between PP matrix and sisal fiber and also to improve the dispersion of the organoclay in PP matrix. The addition of OMMT had insignificantly affected mechanical properties of SF/PP composites. However, flame retardancy and thermal stability of SF/PP composites were improved dramatically with the presence of OMMT.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2636
Author(s):  
Petr Valášek ◽  
Miroslav Müller ◽  
Vladimír Šleger ◽  
Viktor Kolář ◽  
Monika Hromasová ◽  
...  

Composite materials with natural fillers have been increasingly used as an alternative to synthetically produced materials. This trend is visible from a representation of polymeric composites with natural cellulose fibers in the automotive industry of the European Union. This trend is entirely logical, owing to a preference for renewable resources. The experimental program itself follows pronounced hypotheses and focuses on a description of the mechanical properties of untreated and alkali-treated natural vegetable fibers, coconut and abaca fibers. These fibers have great potential for use in composite materials. The results and discussion sections contribute to an introduction of an individual methodology for mechanical property assessment of cellulose fibers, and allows for a clear definition of an optimal process of alkalization dependent on the content of hemicellulose and lignin in vegetable fibers. The aim of this research was to investigate the influence of alkali treatment on the surface microstructure and tensile properties of coir and abaca fibers. These fibers were immersed into a 5% solution of NaOH at laboratory temperature for a time interval of 30 min, 1 h, 2 h, 3 h, 6 h, 12 h, 24 h, and 48 h, rinsed and dried. The fiber surface microstructures before and after the alkali treatment were evaluated by SEM (scanning electron microscopy). SEM analysis showed that the alkali treatment in the NaOH solution led to a gradual connective material removal from the fiber surface. The effect of the alkali is evident from the visible changes on the surface of the fibers.


2021 ◽  
Vol 30 ◽  
pp. 263498332110074
Author(s):  
Henry C Obasi ◽  
Uchechi C Mark ◽  
Udochukwu Mark

Conventional inorganic fillers are widely used as fillers for polymer-based composites. Though, their processing difficulties and cost have demanded the quest for credible alternatives of organic origin like coconut shell fillers. Dried shells of coconut were burnt, ground, and sifted to sizes of 63, 150, 300, and 425 µm. The ground coconut shell particles (CSP) were used as a filler to prepare polypropylene (PP) composites at filler contents of 0% to 40% via injection melt blending process to produce PP composite sheets. The effect of the filler particle size on the mechanical properties was investigated. The decrease in the size of filler (CSP) was found to improve the yield strength, tensile strength, tensile modulus, flexural strength, flexural modulus, and hardness of PP by 8.5 MPa, 15.75 MPa, 1.72 GPa, 7.5 MPa, 100 MPa, and 10.5 HR for 63 µm at 40%, respectively. However, the elongation at break and modulus of resilience of the PP composites were seen to increase with increase in the filler size. Scanning electron microscope analysis showed that fillers with 63 µm particle size had the best distribution and interaction with the PP matrix resulting in enhanced properties.


2020 ◽  
Vol 15 ◽  
pp. 155892502095819
Author(s):  
Qianting Wang ◽  
Yu Zhang ◽  
Weikang Liang ◽  
Jianjie Wang ◽  
Youxin Chen

In this work, the surface of the bamboo fibers (BF) was treated with three kinds of silane coupling agents terminated with amino functional groups (KH550), epoxy functional groups (KH560), and methyl functional groups (KH570) to improve fiber–matrix adhesion. The effects of silane treatment on the mechanical properties and thermal behavior of BF/polypropylene (PP) composites were investigated. Mechanical test results showed that the order of modification effectiveness was KH570 > KH550 > KH560. KH570 treated fiber composite exhibited the best mechanical properties. The tensile strength and flexural strength of 5 wt% KH570 treatment reached to 36.1 and 54.7 MPa, which were 15.4% and 23.6% higher than those of UBF/PP composites. Simultaneously, the thermal stability increased from 467.0°C (UBF) to 470.6°C (KH-570 treated BF). An increase in crystallization temperature (1.7°C) and a decrease in crystallinity (5.8%) occurred upon the addition of 5% KH570 silanes treated bamboo fibers.


2020 ◽  
pp. 002199832096053 ◽  
Author(s):  
Noelle C Zanini ◽  
Rennan FS Barbosa ◽  
Alana G de Souza ◽  
Derval S Rosa ◽  
Daniella R Mulinari

Australian palm residues are generated by palm heart industry in large quantities and are considered an underused material with a composition rich in lignocellulosic structures. This residue is generally utilized as briquettes for energy or sheep feed; however, few works investigate this residue as composite fillers. This work aimed to revalue Australian palm residues (PR) by preparing polypropylene composites through melt mixing, using different fiber contents (0, 5, 10, 20, and 30 wt%), and evaluate the statistical influence of fibers (residues) alkali treatment (MPR) in composites mechanical properties. PR and MPR were evaluated by FTIR, XRD, SEM, TGA, and composites were assessed using thermal and mechanical analysis, in which ANOVA statistical analysis was applied. The residues addition increased the mechanical properties and their treatment enhanced the stiffness of the composites compared to pristine PP. However, ANOVA demonstrated that at low residues contents, surface treatment does not increase fiber-matrix interactions effectively, then tensile properties were statistically similar to PP. Considering tensile properties, 20% MPR showed statistically distinct properties, with significative enhancements; no filler contents dependence was verified. Flexural properties were more sensitive to residue loading, and composites with 30% PR and MPR presented superior mechanical performance. This difference is associated with a higher sensitivity of tensile stress towards fiber-matrix interactions, which was improved with fiber treatment. Also, the residues content and treatment influenced the composites' thermal stability, with better results for PP-MPR. Results indicate that palm residue is an excellent filler for improving composites' thermal and mechanical properties, with a greener character.


2019 ◽  
Vol 944 ◽  
pp. 509-514 ◽  
Author(s):  
Shan Shan Liu ◽  
He Yi Ge ◽  
Yu Zou ◽  
Juan Chen

Maleic anhydride grafted polypropylene compatibilizer (MAPP) and chitosan (CS) were mixed and used as a compound coupling agent to modify the PP matrix. 5 wt% NaOH and 10 wt% NaOH aqueous solution were used to treat corn stalk fiber (CSF), respectively. The effect of the complex coupling agent and the alkali treatment on the mechanical properties of CSF/PP composite was investigated. Morphological observation of the fracture surfaces was accepted to confirm CSF dispersion and wetting with the help of SEM. The results of the water absorption further demonstrated the binding of the interface between the CSF and the PP matrix. The wetting of the CSF in the PP was improved with the addition of the complex compatibilizer (5% MAPP + 5% CS). The formation of chemical bonding between the fiber and the matrix resulted in enhancing the interfacial compatibility between them. Compared with the pure PP, the flexural strength of 15-UT-5MAPPCS (63.14 MPa) and 15-UT-5MAPPCS (69.35 MPa) increased by 22.5% and 34.5%, respectively. The complex compatibilizer can replace alkaline treatment process to improve the mechanical properties of the composite.


2019 ◽  
Vol 956 ◽  
pp. 229-236
Author(s):  
Jian Lin Xu ◽  
Zhou Chen ◽  
Lei Niu ◽  
Cheng Hu Kang ◽  
Xiao Qi Liu

In this paper, Sb2O3/PP composite specimens were prepared by ball milling and melt blending. The effects of Sb2O3 particle size and filling amount on the toughening, reinforcing effect and crystallinity of PP composites were analyzed by notch impact test, tensile test, SEM, XRD and DSC characterization. The experimental results show that the filling of Sb2O3 particles can improve the mechanical properties and crystallization properties of Sb2O3/PP composites. With the increase of filling amount of Sb2O3 particles, the tensile strength and impact strength of Sb2O3/PP composite increased first and then decreased. When the content of Sb2O3 is 2 wt.%, the tensile strength and impact strength of Sb2O3/PP composites reach the maximum. When the filling amount is the same, the crystallization and mechanical properties of nanoSb2O3/PP composites are better than those of micron Sb2O3/PP composites.


Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 152 ◽  
Author(s):  
Nerea Pérez ◽  
Xiao-Lin Qi ◽  
Shibin Nie ◽  
Pablo Acuña ◽  
Ming-Jun Chen ◽  
...  

Polypropylene (PP) is currently widely used in areas requiring lightweight materials because of its low density. Due to the intrinsic flammability, the application of PP is restricted in many conditions. Aluminum trihydroxide (ATH) is reported as a practical flame retardant for PP, but the addition of ATH often diminishes the lightweight advantage of PP. Therefore, in this work, glass bubbles (GB) and octacedylamine-modified zirconium phosphate (mZrP) are introduced into the PP/ATH composite in order to lower the material density and simultaneously maintain/enhance the flame retardancy. A series of PP composites have been prepared to explore the formulation which can endow the composite with balanced flame retardancy, good mechanical properties, and low density. The morphology, thermal stability, flame retardancy, and mechanical properties of the composites were characterized. The results indicated the addition of GB could reduce the density, but decreased the flame retardancy of PP composites at the same time. To overcome this defect, ATH and mZrP with synergetic effect of flame retardancy were added into the composite. The dosage of each additive was optimized for achieving a balance of flame retardancy, good mechanical properties, and density. With 47 wt % ATH, 10 wt % GB, and 3 wt % mZrP, the peak heat release rate (pHRR) and total smoke production (TSP) of the composite PP-4 were reduced by 91% and 78%, respectively. At the same time, increased impact strength was achieved compared with neat PP and the composite with ATH only. Maintaining the flame retardancy and mechanical properties, the density of composite PP-4 (1.27 g·cm−3) is lower than that with ATH only (PP-1, 1.46 g·cm−3). Through this research, we hope to provide an efficient approach to designing flame retardant polypropylene (PP) composites with low density.


Sign in / Sign up

Export Citation Format

Share Document