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Influence of sisal fibre modification on the microbial stability of poly(hydroxybutyrate-co-valerate): thermal analysis

Kittikorn Thorsak, Strömberg Emma, Ek Monica, Karlsson Sigbritt

Polimery

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2022

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Vol. 67, nr 3

93--101

EN

The effect of modification of sisal fibre with propionic anhydride and vinyltrimethoxy silane on the microbiological stability of poly(hydroxybutyrate-co-valerate) (PHBV) was investigated. The effect of the coupling agent – PHBV grafted with maleic anhydride (PHBV-g-MA) was also investigated. The best adhesion at the interface was observed for propionylation of sisal fibre, which improved the thermal properties of the composites. Composites with modified sisal fibre were characterized by higher activation energy (155 kJ/mol), which is related to stronger interactions at the matrix-fibre interface. In the microbial growth test, all biocomposites showed a decrease in molecular weight due to enzymatic degradation by Aspergillus niger. The most resistant to microorganisms was the composite containing propionylated sisal fibre. DMTA and TGA also confirmed the highest microbiological stability of the composite with the addition of propionylated sisal fibre, as evidenced by the smallest change in the properties after the microbiological growth test. In contrast, PHBV- g-MA caused significant enzymatic degradation due to the presence of large amorphous regions.

PL

Zbadano wpływ modyfikacji włókna sizalowego bezwodnikiem propionowym i winylotrimetoksy silanem na stabilność mikrobiologiczną poli(hydroksymaślanu-co-walerianianu) (PHBV). Zbadano również wpływ środka sprzęgającego − PHBV szczepionego bezwodnikiem maleinowym (PHBV-g-MA). Najlepszą adhezję na granicy faz stwierdzono w przypadku zastosowania propionylowania włókna sizalowego, co poprawiło właściwości termiczne kompozytów. Kompozyty z modyfikowanym włóknem sizalowym charakteryzowały się wyższą energią aktywacji (155 kJ/mol), co wiąże się z silniejszymi oddziaływaniami na granicy faz osnowa-włókno. W teście wzrostu drobnoustrojów wszystkie biokompozyty wykazywały zmniejszenie masy cząsteczkowej na skutek enzymatycznej degradacji przez Aspergillus niger. Najbardziej odporny na działanie mikroorganizmów były kompozyt zawierający propionylowane włókno sizalowe. DMTA i TGA potwierdziły również najwyższą stabilność mikrobiologiczną kompozytu z dodatkiem propionylowanego włókna sizalowego, o czym świadczy najmniejsza zmiana badanych właściwości po teście wzrostu mikrobiologicznego. Natomiast, PHBV-g-MA powodował znaczną degradację enzymatyczną ze względu na obecność dużych obszarów amorficznych.

2

Treatment of Contaminated Water from Niger Delta Oil Fields with Carbonized Sisal Fibre Doped with Nanosilica from Ofada Rice Husk

Odunlami Olayemi Abosede, Agboola Oluranti, Odiakaose Ebubechukwu Olive, Olabode Oladipupo Oyindapo, Babalola Oni, Abatan Olubunmi Grace, Owoicho Isaac

Journal of Ecological Engineering

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2022

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Vol. 23, nr 9

297--308

EN

Oil spills contaminate water bodies and hence, cause the death of marine animals. The Niger Delta Oil contaminated water was treated by adsorption using sisal fibre activated carbon (SFAC) doped with silica nanoparticles (SNP) synthesized from Ofada rice husk which was carbonized at temperatures 400 °C and 650 °C. The SNP was synthesized at 600 °C (SNP-1) and 800 °C (SNP-2). The proportion in SFAC: SNP for both temperature values was 4.8:0.2 with a basis of 5 grams of the adsorbent. The samples were characterized by SEM, BET analysis, XRF and XRD. The adsorption equilibrium studies obeyed Langmuir adsorption isotherm; as the linear correlation value was close to unity, with a separation factor of 0.004. SNP-1 shows amophous nature having Fe2O3 and SNP-2 shows crystalline nature which consist of quartz. SNP-2 was used for the study due to its high surface area observed in the BET. High % removal efficiency of 99.84 was attained with silica nanoparticle (SNP-2) integrated in sisal fiber activated carbon (SFAC carbonized at 400 °C).

3

Investigating the Effect of Sisal Fibre Content on Durability Properties of Lightweight Foamed Concrete

Mydin Md Azree Othuman

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 2

141--149

EN

Lightweight foamed concrete is greatly permeable, and its durability performance reduce with rising in the number of voids. In turn to improve its durability properties, the solid matrix of lightweight foamed concrete can be adjusted by incorporating several plant-based fibres. The effect of sisal fibre in lightweight foamed concrete was not explored before in the current body of knowledge. Therefore, there is some uncertainty considering the mechanism by which and the extent to which the sisal fibre may impact lightweight foamed concrete durability properties. Thus, this laboratory study concentrates on distinguishing the potential employment of sisal fibre into lightweight foamed concrete. This investigation aims to establish the durability performance of lightweight foamed concrete with the presence of sisal fibre. Densities of 800 and 1600 kg/m3 were made and assesed. Different weight fractions of sisal fibre of 0.2%, 0.4%,0.6% and 0.8% were utilized. There were four durability perfomance of lightweight foamed concrete were evaluated such as shrinkage, ultrasonic pulse velocity (UPV), porosity and water absorption capacity. The experimental results had indicated that the addition of 0.6% of sisal fibre gave the optimum results for the durability properties. At 0.6% weight fraction of sisal fibre, the fibres reached maximum compaction in the cement matrix, which stemmed in exceptional mix regularity. Further than 0.6% inclusion of sisal fibre, accumulation and non-regularity scattering of fibres was detected, which led to reduction in entire parameters assessed.

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Tensile, Flexual, Impact and Water Absorption Properties of Natural Fibre Reinforced Polyester Hybrid Composites

Prasanna Venkatesh R., Ramanathan K., Srinivasa Raman V.

Fibres & Textiles in Eastern Europe

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2016

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Vol. 24, no. 3 (117)

90--94

EN

In this paper, tensile, flexural, impact properties and water absorption tests were carried out using sisal/unsaturated polyester composite material. Initially the optimum fibre length and weight percentage are estimated. To improve the tensile, flexural and impact properties, sisal fibre was hybridised with bamboo fibre. This work shows that the addition of bamboo fibre in sisal/ unsaturated polyester composites of up to 50% by weight results in increasing the mechanical properties and decreasing the moisture absorption property. In this research work, the effects of fibre treatment and concentration on the mechanical properties of a short natural fibre reinforced polyester hybrid composite are investigated. The fibres were subjected to 10% sodium hydroxide solution treatment for 24 h. The mechanical properties of composites with treated fibres are compared with untreated fibre composites. The fractured surface of the treated fibre composite specimen was studied using Scanning Electron Microscopy (SEM).The treated hybrid composite was compared with an untreated hybrid composite, with the former showing a 30% increase in tensile strength, 27.4% - in flexural strength, and 36.9% - in impact strength, along with an extreme decrease in moisture absorption behaviour.

PL

Badania przeprowadzono stosując kompozyty sizal/poliester i sizal/nienasyconą żywicę poliestrową. Początkowo określono optymalną długość włókien oraz udział procentowy masy w materiale kompozytowym. Dla polepszenia właściwości mechanicznych do włókien sizalowych dodawano włókna bambusowe aż do 50% wagowych. Stwierdzono polepszenie właściwości mechanicznych i, co jest bardzo ważne, zmniejszenie absorpcji wilgoci. Włókna poddawano działaniu 10% roztworu wodorotlenku sodu przez 24h. Badano kompozyty niemodyfikowane i modyfikowana zwracając szczególną uwagę na przełomy obserwowane za pomocą SEM. Stwierdzono polepszenie właściwości mechanicznych hybrydowych kompozytów poddanych modyfikacji, przy czym wytrzymałość na rozciąganie zwiększyła się o 30%, na zginanie 27,4% a wytrzymałość na uderzenia o 36,9%, a jednoczenie absorpcja wody zmniejszyła się znacznie