Pub Date : 2021-09-01DOI: 10.4067/s0718-221x2021000100462
Wengang Hu, Bin Chen, Xiaowen Lin, Huiyuan Guan
The effect of loading type (tension, compression and bolt-bearing) on mechanical properties (elastic modulus, Poisson’s ratio and ultimate strength) of Moso bamboo (Phyllostachys heterocycla var. pubescens) in longitudinal direction was evaluated in this study. In addition, experimental and numerical tests were conducted to evaluate withdrawal force capacity and bending moment resistances of a novel demountable bamboo-bolt joint considering effect of loading type on mechanical parameters used in finite element method. The results showed that loading type had significant effect on mechanical properties of Moso bamboo, especially, for ultimate strength; the values of mechanical properties evaluated in this study measured in tension were all much higher than those measured in bolt-bearing state and followed by compression accordingly; in tension, the tensile elastic modulus and Poisson’s ratio measured at outer surface were bigger than those at inner surface, respectively; finite element method got more accurate results using the mechanical parameters measured in compression than those in tension and bolt-bearing states; the bamboo-bolt joint proposed in this study can be used in lightweight bamboo structures through improving the embedding strength of beech wood in bamboo culm. In conclusion, one should consider the loading type used to obtain the mechanical para meters inputted in finite element method. In addition, further studies will focus on effect of size and geometry of samples used to determine mechanical properties used in finite element method, and the method of improving embedding strength of beech wood in bamboo culm to increase withdrawal force capacity and bending moment resistances of the demountable bamboo-bolt joint proposed in this study.
{"title":"Experimental and numerical study on a novel bamboo joint for furniture considering effect of loading type on mechanical parameters used in finite element method","authors":"Wengang Hu, Bin Chen, Xiaowen Lin, Huiyuan Guan","doi":"10.4067/s0718-221x2021000100462","DOIUrl":"https://doi.org/10.4067/s0718-221x2021000100462","url":null,"abstract":"The effect of loading type (tension, compression and bolt-bearing) on mechanical properties (elastic modulus, Poisson’s ratio and ultimate strength) of Moso bamboo (Phyllostachys heterocycla var. pubescens) in longitudinal direction was evaluated in this study. In addition, experimental and numerical tests were conducted to evaluate withdrawal force capacity and bending moment resistances of a novel demountable bamboo-bolt joint considering effect of loading type on mechanical parameters used in finite element method. The results showed that loading type had significant effect on mechanical properties of Moso bamboo, especially, for ultimate strength; the values of mechanical properties evaluated in this study measured in tension were all much higher than those measured in bolt-bearing state and followed by compression accordingly; in tension, the tensile elastic modulus and Poisson’s ratio measured at outer surface were bigger than those at inner surface, respectively; finite element method got more accurate results using the mechanical parameters measured in compression than those in tension and bolt-bearing states; the bamboo-bolt joint proposed in this study can be used in lightweight bamboo structures through improving the embedding strength of beech wood in bamboo culm. In conclusion, one should consider the loading type used to obtain the mechanical para meters inputted in finite element method. In addition, further studies will focus on effect of size and geometry of samples used to determine mechanical properties used in finite element method, and the method of improving embedding strength of beech wood in bamboo culm to increase withdrawal force capacity and bending moment resistances of the demountable bamboo-bolt joint proposed in this study.","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78954751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.4067/s0718-221x2021000100460
D. Nicholas, Amy Rowlen, D. Milsted
A need exists to develop new organic, environmentally benign wood preservatives for industrial applications to replace the older creosote and pentachlorophenol systems. In this study the performance of creosote at three retentions was compared to a new wood preservative candidate formulated with Polymeric Xylenol Tetrasulfide (PXTS) in an E7 AWPA field study using two sets of southern pine and yellow poplar field stakes treated with three creosote retentions or five retentions of PXTS. The stakes were installed at two test sites and evaluated after 3,5 years, 6 years, and 14 years exposure. After six years of exposure at both sites, which is double the minimum recommended exposure period of three years’ field data for AWPA submission of a proposed new preservative system, the average decay ratings data for southern pine stakes after three years exposure was not sufficient to definitively determine which system provides superior protection against decay and termite attack (Creosote at the AWPA UC4B pole retentions versus pine stakes treated with much lower PXTS levels). However, after a longer exposure time of 14 years the data conclusively shows that pine stakes treated to the utility pole AWPA UC4B creosote retention performed poorer at both sites against decay and termite degradation than pine stakes treated with 26 Kg/m3 PXTS. Similar results were obtained with the yellow poplar stakes. We conclude that: 1) much longer E7 exposure times are necessary then the minimum recommended three years in the AWPA GDA Standard for submission of new systems to definitively determine the efficacy of a proposed oil borne system compared to the efficacy of a traditional organic preservative for commercial applications, and 2) long term field PXTS performance against decay and termite deterioration is equal or greater than that obtained with creosote at about four times the PXTS retention.
{"title":"Comparative performance of Polymeric Xylenol Tetrasulfide versus creosote in an AWPA E7 field stake test","authors":"D. Nicholas, Amy Rowlen, D. Milsted","doi":"10.4067/s0718-221x2021000100460","DOIUrl":"https://doi.org/10.4067/s0718-221x2021000100460","url":null,"abstract":"A need exists to develop new organic, environmentally benign wood preservatives for industrial applications to replace the older creosote and pentachlorophenol systems. In this study the performance of creosote at three retentions was compared to a new wood preservative candidate formulated with Polymeric Xylenol Tetrasulfide (PXTS) in an E7 AWPA field study using two sets of southern pine and yellow poplar field stakes treated with three creosote retentions or five retentions of PXTS. The stakes were installed at two test sites and evaluated after 3,5 years, 6 years, and 14 years exposure. After six years of exposure at both sites, which is double the minimum recommended exposure period of three years’ field data for AWPA submission of a proposed new preservative system, the average decay ratings data for southern pine stakes after three years exposure was not sufficient to definitively determine which system provides superior protection against decay and termite attack (Creosote at the AWPA UC4B pole retentions versus pine stakes treated with much lower PXTS levels). However, after a longer exposure time of 14 years the data conclusively shows that pine stakes treated to the utility pole AWPA UC4B creosote retention performed poorer at both sites against decay and termite degradation than pine stakes treated with 26 Kg/m3 PXTS. Similar results were obtained with the yellow poplar stakes. We conclude that: 1) much longer E7 exposure times are necessary then the minimum recommended three years in the AWPA GDA Standard for submission of new systems to definitively determine the efficacy of a proposed oil borne system compared to the efficacy of a traditional organic preservative for commercial applications, and 2) long term field PXTS performance against decay and termite deterioration is equal or greater than that obtained with creosote at about four times the PXTS retention.","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84515588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.4067/s0718-221x2021000100459
Leon Rogers, Jed Cappellazzi, J. Morrell
Fungi cultured from air-seasoning blackgum and red oak timbers were assessed for their ability to cause wood decay using two hardwoods and one soft wood species in an AWPA E10 soil block test. Weight losses were greatest for bigleaf maple and tended to be much lower on southern pine. Almost a quarter of the 35 taxa tested caused less than 5 % weight loss, suggesting they posed a relatively low decay risk, even under ideal laboratory conditions; despite all fungi tested having the ability to depolymerize wood. Three of the four fungi causing the largest weight losses were brown-rot fungi, although brown-rot fungi represented only small proportion of the total isolates from the original hardwood timbers. These results illustrate wide array of decay capabilities of fungi colonizing air-seasoning red oak and blackgum timbers, and the potential of many isolates to negatively affect wood properties through biodeterioration
{"title":"Decay capabilities of basidiomycetes colonizing air-seasoning red oak and blackgum railroad ties","authors":"Leon Rogers, Jed Cappellazzi, J. Morrell","doi":"10.4067/s0718-221x2021000100459","DOIUrl":"https://doi.org/10.4067/s0718-221x2021000100459","url":null,"abstract":"Fungi cultured from air-seasoning blackgum and red oak timbers were assessed for their ability to cause wood decay using two hardwoods and one soft wood species in an AWPA E10 soil block test. Weight losses were greatest for bigleaf maple and tended to be much lower on southern pine. Almost a quarter of the 35 taxa tested caused less than 5 % weight loss, suggesting they posed a relatively low decay risk, even under ideal laboratory conditions; despite all fungi tested having the ability to depolymerize wood. Three of the four fungi causing the largest weight losses were brown-rot fungi, although brown-rot fungi represented only small proportion of the total isolates from the original hardwood timbers. These results illustrate wide array of decay capabilities of fungi colonizing air-seasoning red oak and blackgum timbers, and the potential of many isolates to negatively affect wood properties through biodeterioration","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78319948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.4067/s0718-221x2021000100466
M. Arslan, Erkan Avci, A. Tozluoğlu, T. Birtürk, A. Saraçbaşi, E. Örtel
Black pine (Pinus nigra) is a significant raw material source for the forest products industry in Turkey. The purpose of this research was to study some chemical, anatomical, physical, and mechanical properties of wood obtained from juvenile black pines planted in Kavaklıdere Muğla, originating from five different locations: Muğla, Balıkesir, Denizli, Bursa, and Kütahya. Although pines originating from Muğla and Balıkesir were good in terms of wood properties, those from Denizli, Bursa, and Kütahya exhibited no remarkable features. Black pine of Muğla origin was recommended for planting in Kavaklıdere and similar habitats, whereas pines of Denizli, Bursa, and Kütahya origins were not recommended. However, pine of Balıkesir origin may be an alternative to that of Muğla origin for black pine plantations at Kavaklıdere and similar sites.
{"title":"Comparison of some wood properties of juvenile black pines of different origin planted in the same habitat","authors":"M. Arslan, Erkan Avci, A. Tozluoğlu, T. Birtürk, A. Saraçbaşi, E. Örtel","doi":"10.4067/s0718-221x2021000100466","DOIUrl":"https://doi.org/10.4067/s0718-221x2021000100466","url":null,"abstract":"Black pine (Pinus nigra) is a significant raw material source for the forest products industry in Turkey. The purpose of this research was to study some chemical, anatomical, physical, and mechanical properties of wood obtained from juvenile black pines planted in Kavaklıdere Muğla, originating from five different locations: Muğla, Balıkesir, Denizli, Bursa, and Kütahya. Although pines originating from Muğla and Balıkesir were good in terms of wood properties, those from Denizli, Bursa, and Kütahya exhibited no remarkable features. Black pine of Muğla origin was recommended for planting in Kavaklıdere and similar habitats, whereas pines of Denizli, Bursa, and Kütahya origins were not recommended. However, pine of Balıkesir origin may be an alternative to that of Muğla origin for black pine plantations at Kavaklıdere and similar sites.","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84409826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-01DOI: 10.4067/s0718-221x2021000100807
K. T. Barbosa, A. Acosta, H. Schulz, I. Santi, R. Delucis, R. Beltrame, D. Gatto
The objective of this study is to evaluate chemical characteristics, as well as antioxidant and antibacterial activities of organic compounds extracted from three Eucalyptus woods and Corymbia maculate wood using ethanol as a solvent. To obtain the ethanolic extracts, 15 g of a powdered wood sample was mixed with 150 mL of ethyl alcohol 99 % PA by constant mechanical stirring, which was further magnetically mixed at 60 oC for 24 h. The extractives were analyzed by means of percent yield, Fourier-transform infrared spectrum, inhibitory index (measured after antimicrobial tests), antioxidant activity, and condensed tannins content. The Eucalyptus dunnii extract showed the highest percent yield. The infrared spectra of all the extractives presented similar profiles, with remarkable bands ascribed to the presence of lipophilic extracts, sterols, fatty acids, and other hydroxylated substances, such as carbohydrates and phenolic compounds. In all cases, the higher the concentration of the extractive was, the higher the antioxidant activity was. The antioxidant activity of Eucalyptus saligna extract stood out since overcame that of the positive control (ascorbic acid). Regarding the condensed tannins content, that extract from Eucalyptus grandis excelled
本研究以乙醇为溶剂，对三种桉树和山杉木中提取的有机化合物的化学特性、抗氧化和抗菌活性进行了研究。为获得乙醇提取物，将15 g木粉样品与150 mL 99% PA的乙醇不断机械搅拌混合，并在60℃下进行24 h的磁混合。通过收率、傅里叶变换红外光谱、抑制指数(抗菌试验后测量)、抗氧化活性和缩合单宁含量来分析提取物。dunnii桉叶提取物提取率最高。所有提取物的红外光谱都呈现出相似的特征，其中有明显的亲脂性提取物、甾醇、脂肪酸和其他羟基化物质，如碳水化合物和酚类化合物。在所有情况下，提取物浓度越高，抗氧化活性越高。桉树提取物的抗氧化活性优于阳性对照(抗坏血酸)。在浓缩单宁含量方面，大桉提取物的浓缩单宁含量最高
{"title":"Biochemical features of organic extractives from Eucalyptus and Corymbia woods using ethanol as a solvent","authors":"K. T. Barbosa, A. Acosta, H. Schulz, I. Santi, R. Delucis, R. Beltrame, D. Gatto","doi":"10.4067/s0718-221x2021000100807","DOIUrl":"https://doi.org/10.4067/s0718-221x2021000100807","url":null,"abstract":"The objective of this study is to evaluate chemical characteristics, as well as antioxidant and antibacterial activities of organic compounds extracted from three Eucalyptus woods and Corymbia maculate wood using ethanol as a solvent. To obtain the ethanolic extracts, 15 g of a powdered wood sample was mixed with 150 mL of ethyl alcohol 99 % PA by constant mechanical stirring, which was further magnetically mixed at 60 oC for 24 h. The extractives were analyzed by means of percent yield, Fourier-transform infrared spectrum, inhibitory index (measured after antimicrobial tests), antioxidant activity, and condensed tannins content. The Eucalyptus dunnii extract showed the highest percent yield. The infrared spectra of all the extractives presented similar profiles, with remarkable bands ascribed to the presence of lipophilic extracts, sterols, fatty acids, and other hydroxylated substances, such as carbohydrates and phenolic compounds. In all cases, the higher the concentration of the extractive was, the higher the antioxidant activity was. The antioxidant activity of Eucalyptus saligna extract stood out since overcame that of the positive control (ascorbic acid). Regarding the condensed tannins content, that extract from Eucalyptus grandis excelled","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88636103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-01DOI: 10.4067/s0718-221x2021000100455
P. Y. Fank, María del Rocío Ramos, Eduardo Antonio Torrán, María Alexandra Sosa-Zitto, J. C. Piter
{"title":"Vigas de pino resinoso del noreste de Argentina bajo cargas de larga duración: Deformaciones, recuperación y criterios de diseño","authors":"P. Y. Fank, María del Rocío Ramos, Eduardo Antonio Torrán, María Alexandra Sosa-Zitto, J. C. Piter","doi":"10.4067/s0718-221x2021000100455","DOIUrl":"https://doi.org/10.4067/s0718-221x2021000100455","url":null,"abstract":"","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79784624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-01DOI: 10.4067/S0718-221X2021000100449
A. Abdulqader
{"title":"Efficient utilization of corn stalk and poplar planer shavings in manufacturing particleboard","authors":"A. Abdulqader","doi":"10.4067/S0718-221X2021000100449","DOIUrl":"https://doi.org/10.4067/S0718-221X2021000100449","url":null,"abstract":"","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78104848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-01DOI: 10.4067/S0718-221X2021000100447
K. S. Shiny, R. Sundararaj
The management of Lyctus africanus, one of the major dry wood pests in the tropical region is difficult due to its secluded habits and long lifecycle and therefore, its control measures are limited to the usage of insecticides. The insecticides particularly the metal salts are effective, but in some cases their leaching leads to concerns about environmental pollution. Nanometal particles are found to be more effective than metal salts. Presently available metal nanoparticles are synthesized using physical or chemical methods and their production results in toxic by-products and are costly. The current investigation deals with synthesis and use of metal nanoparticle for wood protection in an environmentally friendly and cost-effective way. The plant extracts that are reported to have wood preservative properties were used for the synthesis of metal nanoparticles. Copper oxide and zinc oxide nanoparticles were synthesized using leaf extracts of Lantana camara. The efficacy of the synthesized Lantana camara leaf extract and copper oxide or zinc oxide nanoparticle formulation as a wood protectant was tested against Lyctus africanus according to standard BIS. The formulation of copper oxide nanoparticle and Lantana camara leaf extract effectively protected the treated rubberwood blocks from Lyctus africanus attack, when compared to zinc oxide nanoparticle Lantana camara leaf extract formulation and can be developed into a stable, ecofriendly wood preservative.
{"title":"Biologically synthesised copper oxide and zinc oxide nanoparticle formulation as an environmentally friendly wood protectant for the management of wood borer, Lyctus africanus","authors":"K. S. Shiny, R. Sundararaj","doi":"10.4067/S0718-221X2021000100447","DOIUrl":"https://doi.org/10.4067/S0718-221X2021000100447","url":null,"abstract":"The management of Lyctus africanus, one of the major dry wood pests in the tropical region is difficult due to its secluded habits and long lifecycle and therefore, its control measures are limited to the usage of insecticides. The insecticides particularly the metal salts are effective, but in some cases their leaching leads to concerns about environmental pollution. Nanometal particles are found to be more effective than metal salts. Presently available metal nanoparticles are synthesized using physical or chemical methods and their production results in toxic by-products and are costly. The current investigation deals with synthesis and use of metal nanoparticle for wood protection in an environmentally friendly and cost-effective way. The plant extracts that are reported to have wood preservative properties were used for the synthesis of metal nanoparticles. Copper oxide and zinc oxide nanoparticles were synthesized using leaf extracts of Lantana camara. The efficacy of the synthesized Lantana camara leaf extract and copper oxide or zinc oxide nanoparticle formulation as a wood protectant was tested against Lyctus africanus according to standard BIS. The formulation of copper oxide nanoparticle and Lantana camara leaf extract effectively protected the treated rubberwood blocks from Lyctus africanus attack, when compared to zinc oxide nanoparticle Lantana camara leaf extract formulation and can be developed into a stable, ecofriendly wood preservative.","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82165679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-01DOI: 10.4067/S0718-221X2021000100448
Jun Zhang, Bowen Liu, Yunxia Zhou, H. Essawy, Jinxing Li, Qian Chen, Xiaojian Zhou, G. Du
In this study, an easily prepared bio-based abrasive grinding wheel based on tannin–glyoxal–urea (TGU) thermosetting matrix is presented.The synthesised resin was prepared via co-polycondensation reaction of glyoxal and ureawith condensed tannin, which is a forest-derived product. Fourier transform infrared spectroscopy and electrospray ionisation mass spectrometry results confirmed that urea and glyoxal react well under acidic conditions and that –(OH)CH–NH–group is primarily involved in TGU cross-linking. Differential scanning calorimetry, thermomechanical analysis and thermogravimetric analysis investigations showed that the preparation of TGU resin is easier compared to commercial phenol–formaldehyde (PF) resin; moreover, TGU resin has a more robust chemical network structure, which contributes efficiently to heat resistance and improved mechanical properties. This observation is supported by Brinell hardness, compression resistance and grinding testing; these showed that the new grinding wheel acquired higher hardness, superior resistance against compression and stronger abrasion resistance compared with a PFbased grinding wheel prepared in the laboratory. Moreover, few holes and no cracks were found in the new grinding wheel. 1Southwest Forestry University, Yunnan Key Laboratory of Wood Adhesives and Glued Products, Kunming, China. 2Southwest Forestry University, Key Laboratory of State forestry and Grassand Administration on highly efficient utilisation of forestry biomass resources in Southwest of China, Kunming, China. 3National Research Centre, Department of Polymers and Pigments, Dokki, Cairo, Egypt. ♠Corresponding authors: chenqian@hit.edu.cn ; xiaojianzhou1982@163.com Received: 10.09.2020 Accepted: 19.04.2021 Maderas. Ciencia y tecnología 2021 (23): 48, 1-16 Universidad del Bío-Bío 2
{"title":"Preparation and performance of tannin-glyoxal-urea resin-bonded grinding wheel loaded with SiO2 reinforcing particles","authors":"Jun Zhang, Bowen Liu, Yunxia Zhou, H. Essawy, Jinxing Li, Qian Chen, Xiaojian Zhou, G. Du","doi":"10.4067/S0718-221X2021000100448","DOIUrl":"https://doi.org/10.4067/S0718-221X2021000100448","url":null,"abstract":"In this study, an easily prepared bio-based abrasive grinding wheel based on tannin–glyoxal–urea (TGU) thermosetting matrix is presented.The synthesised resin was prepared via co-polycondensation reaction of glyoxal and ureawith condensed tannin, which is a forest-derived product. Fourier transform infrared spectroscopy and electrospray ionisation mass spectrometry results confirmed that urea and glyoxal react well under acidic conditions and that –(OH)CH–NH–group is primarily involved in TGU cross-linking. Differential scanning calorimetry, thermomechanical analysis and thermogravimetric analysis investigations showed that the preparation of TGU resin is easier compared to commercial phenol–formaldehyde (PF) resin; moreover, TGU resin has a more robust chemical network structure, which contributes efficiently to heat resistance and improved mechanical properties. This observation is supported by Brinell hardness, compression resistance and grinding testing; these showed that the new grinding wheel acquired higher hardness, superior resistance against compression and stronger abrasion resistance compared with a PFbased grinding wheel prepared in the laboratory. Moreover, few holes and no cracks were found in the new grinding wheel. 1Southwest Forestry University, Yunnan Key Laboratory of Wood Adhesives and Glued Products, Kunming, China. 2Southwest Forestry University, Key Laboratory of State forestry and Grassand Administration on highly efficient utilisation of forestry biomass resources in Southwest of China, Kunming, China. 3National Research Centre, Department of Polymers and Pigments, Dokki, Cairo, Egypt. ♠Corresponding authors: chenqian@hit.edu.cn ; xiaojianzhou1982@163.com Received: 10.09.2020 Accepted: 19.04.2021 Maderas. Ciencia y tecnología 2021 (23): 48, 1-16 Universidad del Bío-Bío 2","PeriodicalId":18092,"journal":{"name":"Maderas-ciencia Y Tecnologia","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81825592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-01DOI: 10.4067/S0718-221X2021000100446
C. Cavinato, M. Poletto
Thermal analysis is a powerful tool to predict the composition and thermal stability of different materials. In this work, thermogravimetric analysis of Cedrela odorata, Marmaroxylon racemosum and Tectona grandis was carried out at four different heating rates (5 °C·min-1, 10 °C·min-1, 20 °C·min-1 and 40 °C·min-1) in a non-isothermal condition. The degradation kinetics was evaluated based on Flynn-Wall-Ozawa and Criado methods. The half-life time of wood degradation reaction was also studied. The wood thermal degradation process in an oxidizing atmosphere can be divided in dehydration, devolatilization, and combustion. The kinetic results revels apparent activation energy values of 130-240 kJ·mol-1 for Tectona grandis, 150-191 kJ·mol-1 for Marmaroxylon racemosum and 188-205 kJ·mol-1 for Cedrela odorata, when conversion values ranged from 0,1-0,5. The most probable degradation mechanism for wood species studied is a diffusion model based on a three-dimensional diffusion. Cedrela odorata presented the lowest reaction half-life time while Marmaroxylon racemosum showed the highest. On the basis of these results, it can be concluded that Flynn-Wall-Ozawa and Criado methods associated with half-life time of reaction may contribute to better understand the wood degradation before use it in polymer composites.
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