Browsing by Author "Pabasara, WGA"

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item: Conference-Abstract
Exploring the value addition potential of the local rice straw varieties
(Society of Materials Engineering Students, Department of Materials Science and Engineering, University of Moratuwa, 2017-03) Nanayakkara, MPA; Pabasara, WGA; Samarasekara, AMPB; Amarasinghe, DAS; Sivahar, V
Polymers play a critical role in engineering applications today. Cellulose is the most abundant renewable natural biopolymer on earth. It is present in a wide variety of living species including plants and some marine animals. Rice is the main food of the inhabitants of Sri Lanka. The total land devoted for paddy is estimated to be about 708,000 hectares at present in Sri Lanka. Rice straw is a rice by-product produced after harvesting paddy. Rice straw is a major agricultural waste product in Sri Lanka. There is no effective value addition to local rice straw today. Rice straw contains considerable amount of cellulose with hemicelluloses and lignin. This research is based on investigating the possibility of extraction of cellulose from most frequently used traditional rice varieties (Suwandel and Raththal) and technically modified rice varieties (BG300 and BG352) in Sri Lanka. The dried and cleaned rice straw was milled using a grinder to produce fine powder of rice straw. Sieve analysis method was used to analyze the rice straw powder and equal or less than 150 ? m particle size was selected for the cellulose extraction. Pure cellulose was extracted from BG 352 rice straw variety after following de-waxing, deligni? cation, hemicellulose and silica removal processes. Same extraction procedure was followed for BG 300, Suwandel and Raththal rice varieties. The complete removal of non-cellulosic materials from rice straw was confirmed by FTIR spectroscopy after each chemical purification step. According to the experimental results, highest cellulose yield was obtained from rice straw of Suwandel (35.2%). Other types of rice varieties showed cellulose yield of BG300 (27.8%), BG352 (29.3%) and Rathhal (26.8%). Key feature of this research is developing new processes and technologies to convert Sri Lankan agricultural waste into value - added product of cellulose. These extracted cellulose material can be used for different engineering applications.
item: Conference-Full-text
Investigation of mechanical properties of rice straw ash-filled natural rubber compounds
(IEEE, 2021-07) Fernando, ANA; Pabasara, WGA; Gayashini, KY; Liyanage, DN; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
Rice straw is the one of highest plant-based waste generated in Sri Lanka. Farmers burn rice straw without taking any advantage making substantial air pollution. It is found that rice straw ash contains a significant amount (62%-82%) of silica which is a prominent reinforcing filler material in rubber compounding. The present research work focuses on incorporation of rice straw ash as an alternative filler material in rubber compounding. Up to date, different ratios of rice straw ash has been incorporated with selected rubber compound replacing the silica filler loading and tensile, tear strength, hardness, compression set properties have been investigated. These properties were compared with those of the reference sample prepared according to the same formulation but without adding rice straw ash. The sample containing the same proportion of rice straw ash and silica showed the highest tensile strength compared with that of the control sample. Further, tensile strength of the sample which contained only rice straw ash was also higher than that of the control sample. The rice straw ash has a strong ability to improve the tensile properties of the rubber vulcanizates, while it negatively affects the other mechanical properties such as hardness, tear strength and compression set.
item: Conference-Full-text
Novel thermogravimetry based analytical method for cellulose yield prediction of Sri Lankan rice straw varieties
(IEEE, 2018-05) Samarasekara, AMPB; Nanayakkara, MPA; Pabasara, WGA; Amarasinghe, DAS; Karunanayake, L; Chathuranga, D
Rice straw is the largest residue of Sri Lankan paddy cultivation which has not yet subjected to an effective value addition. But, rice straw can be converted to a high value product as it contains significant amount of Cellulose. Therefore, it is beneficial in many aspects to identify rice straw varieties which provide a sufficient cellulose yield. This research work focuses on introducing a novel, easy to use method based on Thermogravimetric Analysis to predict cellulose yield from most abundant traditional (Suwandel, Raththal) and technically modified (BG300, BG352) rice straw varieties in Sri Lanka. The above method was validated by comparing the results with the yields from established three-step wet chemical method. Proposed method showed a high level of accuracy as percentage variations were less than 5% for all four varieties. Highest cellulose yield was obtained from the rice straws of Suwandel variety. This study reveals a potentially effective course of value addition for Sri Lankan agricultural waste.
item: Conference-Abstract
Synthesis and characterization of cellulose from locally available rice straw
(2017) Nanayakkara, MPA; Pabasara, WGA; Samarasekara, AMPB; Amarasinghe, DAS; Karunanayake, L
Rice is the main agricultural food in Sri Lanka today. Paddy crops are cultivated as a wetland crop in all the districts. Rice straw is a waste product of the rice harvest that is generated in equal or greater quantities than the rice itself.Despite these larger quantities, rice straw is frequently burned in open air by farmers which makes it a significant source of pollution. In the search for possible uses of rice straw, it was found that rice straw contains considerable amount of cellulose which pave the way for the production of cellulose. This study mainly focuses on the synthesis and characterization of cellulose from rice straws of most frequently used traditional (Suwandel, Raththal) and technically modified (BG300, BG352) rice varieties in Sri Lanka. Up to date, pure cellulose has been separately isolated from rice straws of above mentioned four rice varieties after following a three-step de-waxing, delignification and hemicellulose (and silica) removal process. The formation of pure cellulose and complete removal of non-cellulosic materials from rice straw was confirmed by FTIR spectroscopy after each chemical purification step. Highest cellulose yield was observed from rice straws of Suwandel variety (35.2%). Other rice varieties showed cellulose yield BG352 (29.3%), BG300 (27.9%) and Raththal (25.1%).
item: Conference-Full-text
Utilization of paddy husk carbon black as an alternative filler material in rubber industry
(IEEE, 2022-07) Pabasara, WGA; Saputhanthree, A; Weragoda, VSC; Rathnayake, M; Adhikariwatte, V; Hemachandra, K
Paddy husk (rice husk) is an abundant agricultural waste product in Sri Lanka. The utilization of paddy husk has drawn widespread attention worldwide. In this study, the main focus is to produce carbon black from the paddy husk waste. The ability to use Paddy Husk Carbon Black (PHCB) as a substitute raw material for conventional carbon black has been investigated during the study by analyzing the physical and mechanical properties of the selected rubber compound. Based on the particle size of the ball-milled PHCB powder, tyre inner liner compound was selected, and the compound formula was prepared for seven different ratios of PHCB and existing industrial carbon black type (N330). The rheological properties, tensile properties, tear resistance, bonding strength and age analysis were performed in order to find the best PHCB composition with the optimum properties. The sample containing 40% of PHCB and 60% N330 carbon black amount showed the optimum properties which satisfied the available industry specification limits and the properties of the reference sample. Hence, this is an effective way to reduce the filler cost of the rubber compound as well as it provides a sustainable solution for paddy husk waste management.