Effect of Alkaline Treatment on Structural Characterisation, Thermal Degradation and Water Absorption Ability of Coir Fibre Polymer Composites

Yew, Been Seok; Muhamad, Martini; Mohamed, Saiful Bahri; Wee, F. H.

doi:10.17576/jsm-2019-4803-19

Cited by 39 publications

(21 citation statements)

References 30 publications

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“…This could be due to the carboxyl and acetyl groups in hemicelluloses being soluble or easy to dissolve in aqueous alkali solution, thus causing the peak to disappear. The same phenomenon coincided with previous research which reported that alkali treatment removed hemicellulose [38,39]. The existence of that peak in combination-pretreated wood was correlated with succinic acid impregnation after alkali immersion.…”

Section: Chemical Changes To Densified Wood Under Several Treatment C...supporting

confidence: 91%

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Effect of Sodium Hydroxide, Succinic Acid and Their Combination on Densified Wood Properties

Augustina

Wahyudi

Dwianto

et al. 2022

Forests

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The effect of NaOH, succinic acid and their combination used as pretreatments on selected properties of densified wood samples of pisang putih (Mezzettia spp.), nyatoh (Palaquium spp.) and sepetir (Sindora spp.) has been studied. The properties of these samples were then compared with those of untreated wood (control) and densified wood samples without any pretreatment (HD wood). For alkali-pretreatment, after immersion in 10% NaOH (w/w) for 1, 2 and 3 h, the samples were immediately compressed; for acid-pretreatment, the sample was impregnated with 10% succinic acid (w/w) using a vacuum of −50 kPa for 30 min and a pressure of 7 bar for 2 h before pressing; while for the combination-pretreatment, the sample was initially immersed in 10% NaOH then impregnated with 10% succinic acid (w/w) and finally densified/compressed. Compression was applied in a radial direction and carried out in an open system using a hot press machine at 180 °C and 7 MPa specific pressure for 30 min with a 40% compression ratio. The results showed that densified wood with or without pretreatment had a higher specific gravity (SG) than the control, whereas sepetir wood showed the greatest increase in SG. The alkali- and combination-pretreatments resulted in a higher C-set value than in the control, HD and acid-pretreated samples. Acid-pretreatment resulted in the best improvement in dimensional stability compared to the other pretreatments. Increasing the immersion time in NaOH solution was proven to be able to increase dimensional stability both in alkali- and combination-pretreatments, although water absorption values varied.

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Section: Chemical Changes To Densified Wood Under Several Treatment C...supporting

confidence: 91%

“…Chen et al [17] added that the shift in wavelength occurs when a 10% concentration is applied. The shift also occurred in alkali-treated coir fibers with 24 h and 48 h of immersion time [38].…”

Section: Chemical Changes To Densified Wood Under Several Treatment C...mentioning

confidence: 76%

Effect of Sodium Hydroxide, Succinic Acid and Their Combination on Densified Wood Properties

Augustina

Wahyudi

Dwianto

et al. 2022

Forests

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“…For the composite with a ratio of 1:1, the main thermal degradation stage occurred at around 250 to 410 • C, whereas for the ratio of 3:1, it happened at 290 to 450 • C. For the ratio of 1:3, the degradation occurred at 250 to 410 • C. On the other hand, for the composite containing alkali-treated fibers at a ratio of 3:1, thermal degradation occurred at a lower temperature at around 245 to 380 • C. From the outcomes, it was evident that alkaline treatment on fiber decreases the thermal degradation of the composites compared to the untreated fiber [122]. According to Yew et al [48], untreated fiber has a larger moisture content than treated fiber, owing to the increased amount of hemicelluloses and lignin, resulting in more moisture absorption in the fibers. When untreated fiber is heated, there is greater weight loss due to the evaporation of moisture.…”

Section: Thermal Degradation Stability Performance Of Hybrid Natural Fiber-reinforced Thermoplastic Compositesmentioning

confidence: 96%

“…From the outcomes, it was evident that alkaline treatment on fiber decreases the thermal degradation of the composites compared to the untreated fiber [ 122 ]. According to Yew et al [ 48 ], untreated fiber has a larger moisture content than treated fiber, owing to the increased amount of hemicelluloses and lignin, resulting in more moisture absorption in the fibers. When untreated fiber is heated, there is greater weight loss due to the evaporation of moisture.…”

Section: Thermal Degradation Stability Performance Of Hybrid Natural Fiber-reinforced Thermoplastic Compositesmentioning

confidence: 99%

Thermogravimetric Analysis Properties of Cellulosic Natural Fiber Polymer Composites: A Review on Influence of Chemical Treatments

et al. 2021

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Natural fiber such as bamboo fiber, oil palm empty fruit bunch (OPEFB) fiber, kenaf fiber, and sugar palm fiber-reinforced polymer composites are being increasingly developed for lightweight structures with high specific strength in the automotive, marine, aerospace, and construction industries with significant economic benefits, sustainability, and environmental benefits. The plant-based natural fibers are hydrophilic, which is incompatible with hydrophobic polymer matrices. This leads to a reduction of their interfacial bonding and to the poor thermal stability performance of the resulting fiber-reinforced polymer composite. Based on the literature, the effect of chemical treatment of natural fiber-reinforced polymer composites had significantly influenced the thermogravimetric analysis (TGA) together with the thermal stability performance of the composite structure. In this review, the effect of chemical treatments used on cellulose natural fiber-reinforced thermoplastic and thermosetting polymer composites has been reviewed. From the present review, the TGA data are useful as guidance in determining the purity and composition of the composites’ structures, drying, and the ignition temperatures of materials. Knowing the stability temperatures of compounds based on their weight, changes in the temperature dependence is another factor to consider regarding the effectiveness of chemical treatments for the purpose of synergizing the chemical bonding between the natural fiber with polymer matrix or with the synthetic fibers.

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“…After analysis, it was found that the residual weight of raw CSW 11% lower compare to raw CSW. When the treated fibres were subjected to heat, less chars were generated and resulting in lower amount of residual weight [27].…”

Section: Thermogravimetric Analysis (Tga)mentioning

confidence: 99%

Microwave Irradiation Optimization for Efficient Lignin Removal From Cocoa Shell Waste Using Alkali

Ahmad

Ibrahim²,

Mahmud³

et al. 2021

IIUMEJ

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This paper reports a study to determine the optimum conditions of microwave in assisting alkali treatment for removing lignin from cocoa shell waste (CSW). The CSW was mixed with 5% of NaOH solution at the ratio of 1: 10 of weight to volume of the alkaline before being irradiated in a microwave oven. Various microwave powers (200-400 W), temperature settings (60-80 °C) and irradiation times (10-20 min) were tested on 15 samples set by the Box-Behnken design. The lignin removal was analysed using a 72 % sulfuric acid treatment method. A quadratic equation was employed to the response surface and statistical analysis conducted to confirm the adequacy of the model. The plots show that the optimum microwave conditions are 400 W, 76 °C and 19 min, which were capable to remove 86.57% of lignin. Thermogravimetric analysis and micrographs revealed different decomposition temperature of lignin and morphology of extensively-pored surface of treated CSW, respectively. ABSTRAK: Kajian ini adalah berkaitan penentuan keadaan optimal ketuhar gelombang mikro bagi membantu menyingkirkan lignin daripada sisa kulit biji koko (CSW) menggunakan rawatan alkali. CSW dicampurkan dengan larutan NaOH 5 % pada nisbah 1:10 berat kepada isipadu larutan alkali sebelum campuran dipanaskan ke dalam ketuhar gelombang mikro. Pelbagai keadaan ujian dibuat pada ketuhar gelombang mikro seperti tenaga (200-400 W), suhu ketuhar (60-80 °C) dan masa pemanasan (10-20 min) ke atas 15 sampel mengikut reka bentuk statistik Box-Behnken. Kadar penyingkiran lignin ditentukan dengan menggunakan kaedah rawatan larutan asid sulfurik berkepekatan 72 %. Persamaan kuadratik telah digunakan ke atas permukaan respon dan analisis statistik telah dilakukan bagi memastikan kesesuaian model. Plot-plot menunjukkan keadaan optima ketuhar gelombang mikro adalah pada 400 W, 76 °C dan 19 min iaitu berupaya menyingkirkan sebanyak 86.57% lignin. Analisis thermogravimetri dan mikrograf masing-masing menunjukkan perbezaan suhu penguraian lignin dan morfologi permukaan CSW yang dirawat didapati berliang dengan banyaknya.

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Effect of Alkaline Treatment on Structural Characterisation, Thermal Degradation and Water Absorption Ability of Coir Fibre Polymer Composites

Cited by 39 publications

References 30 publications

Effect of Sodium Hydroxide, Succinic Acid and Their Combination on Densified Wood Properties

Effect of Sodium Hydroxide, Succinic Acid and Their Combination on Densified Wood Properties

Thermogravimetric Analysis Properties of Cellulosic Natural Fiber Polymer Composites: A Review on Influence of Chemical Treatments

Microwave Irradiation Optimization for Efficient Lignin Removal From Cocoa Shell Waste Using Alkali

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