Browsing by Author "Ratnakumar, A"

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item: Conference-Full-text
Effect of particle size distribution of rice straw on cellulose extraction
(IEEE, 2020-07) Ratnakumar, A; Samarasekara, AMPB; Amarasinghe, DAS; Karunanayake, L; Weeraddana, C; Edussooriya, CUS
Cellulose has become a wonder material in the present context of research and development since it is fibrous and tough, hence biodegradable, biocompatible, and renewable natural polymer which can be employed in various industrial applications. Nowadays, rice straw as a cellulose source has gained momentum as rice is one of the major crops grown in most of the tropical and subtropical countries of the world with half of the world population consuming it as the major food source. Chemical extraction and purification method is found to be the most efficient method for cellulose extraction from lignocellulosic biomass. Therefore, it is of paramount important to investigate the influence of parent materials on the synthesis process and the properties of the yield. In this research, effect of particle size distribution of locally available rice straw on cellulose synthesis was studied. Study revealed that after the series of chemical treatments M-75 yielded 27.19 ± 0.98 percent, M-250 yielded 38.31 ± 0.86 percent and M-H yielded 33.68 ± 0.68 percent cellulose. FTIR analysis revealed the sequential and complete removal of lignin (1516 cm−1, aromatic skeletal vibrations), hemicellulose (1729 cm−1, carbonyl stretching) and silica (796 cm−1, Si–O–Si stretching) thus, confirms the final product as cellulose. SEM images showed that M-75 exhibited whisker like structure whereas M-250 showed fibrillar network structure. These findings will have profound influence upon extracting cellulose from agricultural biomass.
item: Conference-Full-text
Individualization of nanofibrillated cellulose from Sri Lankan rice straw: structural characteristics and thermal properties
(IEEE, 2021-07) Ratnakumar, A; Samarasekara, AMPB; Amarasinghe, DAS; Karunanayake, L; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
Rice straw is the agricultural production residue which is considered as an agricultural waste. Though it is utilized in various ways, there is a greater possibility for value addition by disintegrating nanofibrillated cellulose from this commercially underutilized waste material. In this study, nanofibrillated cellulose (NFC) was individualized from locally available rice straw variety Murunkan via chemo-mechanical treatments. Firstly, cellulose fibers were extracted from rice straw via a set of chemical processes. Then using high intensity ultrasonication (HIUS) treatment acquired cellulose fibers were individualized into nanofibrillated cellulose. Structural, morphological and thermal behavior of NFC throughout the chemo-mechanical processes were studied. FTIR analysis confirmed that the chemical composition of nanofibrillated cellulose was mainly cellulose where amorphous natured hemicellulose and lignin were effectively removed during chemical processes. From the set of chemical processes, Murunkan variety yielded around 34 per cent cellulose fibers. Out of these cellulose fibers around 17 per cent NFC was individualized via the HIUS treatment. Microscopy study showed that the diameters of the extracted NFC ranged between 100 to 200 nm. Findings of this study will not only add value to the rice straw but also embrace sustainable transition to a bioeconomy in the country.
item: Conference-Full-text
Microfibrillated cellulose fabrication and characterization from sri lankan rice straw: a comparison between traditional and hybrid variety
(IEEE, 2021-07) Ratnakumar, A; Samarasekara, AMPB; Amarasinghe, DAS; Karunanayake, L; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
Rice is one of the major cereal crops cultivated globally. In the recent past, rice straw has gained momentum as a source of cellulose. However, it is notable that rice straw generated from rice cultivation has less or no commercial value. In this study, microfibrillated cellulose (MFC) was extracted from Sri Lankan traditional rice straw variety Pachaperumal and hybrid variety BG352 in two distinct stages. Initially, a series of chemical treatment methods that includes removal of wax and oil, lignin, hemicellulose and silica was employed to extract cellulose fibers from the aforementioned rice straw varieties. Then, using high-intensity ultrasonication (HIUS) process microfibrillated cellulose (MFC) was isolated from the obtained chemically extracted cellulose fibers. FTIR analysis validated that the chemical composition of MFC from both varieties were mainly cellulose where hemicelluloses and lignin were successfully removed during the set of chemical processes. Study revealed that around 34 per cent cellulose was extracted from Pachaperumal and around 25 per cent cellulose was extracted from BG352. Out of these chemically extracted cellulose fibers around 16 per cent of MFC was disintegrated from Pachaperumal and around 9 per cent from BG352 via HIUS process. SEM analysis showed that the diameters of the MFC were in 200 to 300 nanometer range Results indicated that traditional variety yielded high amount of MFC than technically modified variety via the efficient multi-step treatment process with potential industrial applications.
item: Article-Full-text
Path towards a sustainable bioeconomy : conversion of locally available rice straw to nanocellulose
(2021) Ratnakumar, A; Samarasekara, B; Amarasinghe, S; Rathnayake, S; Karunanayake, L
The Sri Lankan agriculture sector has the potential to support a national bioeconomy. Rice straw is a key by-product generated from paddy cultivation. While it is traditionally treated as a waste matter, straw can be a valuable resource in producing biomass fibers in the green composite production due to properties such as recyclability, biodegradability, renewability, nontoxicity, and high functionality.
item: Conference-Full-text
Process optimization of microfibrillated cellulose extraction from cotton waste using response surface methodology
(IEEE, 2021-07) Jayasinghe, JMR; Ratnakumar, A; Samarasekara, AMPB; Amarasinghe, DAS; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
Cotton is a natural staple fiber that mostly consists of cellulose compared to wood. The major economic value of cotton is in textile industry. Over the recent past years the demand for cotton consumption has increased significantly than its production. In textile manufacturing, cotton is blended with various other synthetic fibers such as polyester, nylon and lycra to obtain the desired properties. Though fabric recycling methods are available for pre-consumer garment waste, the processes are quite complicated in actual practice. In this work Microcrystalline Cellulose (MCC) extracted from cotton fabric waste was converted into Microfibrillated Cellulose (MFC) using acid hydrolysis method. However, the major challenge in using acid hydrolysis method is the low amount of yield. Three experimental factors that includes; acid concentration, hydrolysis time and temperature show the highest effect in yield and quality of MFC. Therefore, this experiment was designed to optimize the effect of these three independent factors on yield (%) and width (nm) of MFC. Response surface methodology was adapted to design the experiment and ANOVA statistical test results were used to determine the significant effect of those listed parameters on acid hydrolysis.
item: Conference-Full-text
Property analysis of cellulose fibers extracted from traditional rice straw varieties
(IEEE, 2020-07) Ratnakumar, A; Samarasekara, AMPB; Amarasinghe, DAS; Karunanayake, L; Weeraddana, C; Edussooriya, CUS; Abeysooriya, RP
Agriculture sector plays a vital role in Sri Lankan economy. Although the country is moving towards industrialization, agricultural sector still contributes substantially to both foreign exchange earnings and GDP. Straw generated from paddy cultivation is widely considered as agricultural waste as it has less commercial value. However, cellulose is the main component in paddy straw, which is a renewable resource, gains increasing importance due to its low cost and wide availability. The aim of this study was to extract cellulose fibers from Sri Lankan traditional rice straw varieties Murunkan, Pachchaperumal and Moddaikarupan via a series of chemical treatments and to ascertain their structure, morphology and thermal properties. Study revealed that higher amount of cellulose fibers were extracted from Moddaikarupan variety (38.31 ± 0.86 percent), then from Murunkan variety (33.68 ± 0.68 percent) and lastly from Pachchaperumal variety (33.63 ± 0.10 percent). Fourier transform Infrared (FTIR) analysis showed the successive and complete removal of noncellulosic components from the rice straw. Morphology of rice straw during the extraction process were distinct when the noncellulosic components were removed from rice straw. This study affirms that locally available rice straw varieties can be exploited as cellulose source.
item: Conference-Abstract
Structural analysis of cellulose fibers and rice straw ash derived from Sri Lankan rice straw
Ratnakumar, A; Samarasekara, AMPB; Amarasinghe, DAS; Karunanayake, L
Being an agricultural country, Sri Lanka generates over eight million metric tonnes of rice straw per annum as a byproduct of the paddy cultivation. Currently rice straw is burnt or ploughed into the field without being converted into a productive output. One such output can be isolating the cellulose fibers from this under-utilized waste material. The availability of rice straw is highly seasonal. In this study, cellulose fibers were extracted from rice straw via a three step chemical purification method straw which yeielded 33.4 ± 0.52 percent. The structure, chemical composition, morphology and thermal properties of rice straw, cellulose and rice straw ash were investigated using laser diffracted particle size analyzer, Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometer, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). FTIR results and SEM images show the removal of lignin and hemicellulose and silica at each step of the isolation process. XRD results exhibit the increase in crystallinity of the fibers. This study reveals that thermal and structural properties have increased after the chemical isolation and purification treatment.
item: Conference-Full-text
Study on thermal endurance of plasticizer in locally manufactured electrical cable insulation
(IEEE, 2022-07) Egodage, DP; Dodampola, R; Ratnakumar, A; Weragoda, SC; Amarasinghe, DAS; Samarasekara, AMPB; Attygalle, D; Rathnayake, M; Adhikariwatte, V; Hemachandra, K
Electrical cables are collections of one or more electrical conductors, which are separately insulated and covered together using a sheathing material. Since air does not perform well as a good insulation material, an insulation material is also introduced to resist the passing of electrical current in the radial direction. This will prevent electrical leakage and protect the stability of wire material by concealing it from environmental attacks such as heat and humidity. This paper analyzes the kinetics of the thermal endurance of plasticizers present in locally available electrical cable insulations. For this purpose, a model was developed to map higher temperature accelerated plasticizer evaporation kinetics to lower temperature practically experiencing values. Plasticizer evaporation data were collected in the range of 80-160 °C. Since the plasticizer evaporation reaction occurs over the considered temperature range, notable physical transitions (e.g., crystallization or glass transition) were not observed within the mentioned temperature range. Therefore, The Arrhenius-principle-based approach was employed to map accelerated condition measurements to ambient condition evaporation. An Experimentally determined evaporation behavior was used to define the evaporation kinetics of plasticizers. It was observed that the rate constant of plasticizer evaporation increases with the increasing temperature.