Peng Liu, Bin Bai, Cui Wang, Yunan Chen, Zhiwei Ge, Wenwen Wei, Hui Jin^*

Journal of Renewable Materials, Vol.9, No.12, pp. 2159-2174, 2021, DOI:10.32604/jrm.2021.016166

Abstract In this paper, a simple method to plate a hydrophobic coating on the inner surface of a small-scaled tube was proposed, where the coating consisted of carbon microspheres. Three common plastics polystyrene, polycarbonate and polyethylene were used as the feedstocks to be processed in supercritical water in a quartz tubular reactor. After reaction, the contact angle of droplet on the inner surface of the quartz tube was turned out to be over 100°, significantly larger than that of the blank tube 54°. When processing polystyrene in the 750C supercritical water for 10 min, the largest contact angle was obtained, up… More > Graphic Abstract

Liping Yu¹, Zhongyou Luo¹, Lifen Li¹, Xuedong Xi^2,3, Zhigang Wu^1,2,*, Bengang Zhang^4,*

Journal of Renewable Materials, Vol.9, No.12, pp. 2143-2157, 2021, DOI:10.32604/jrm.2021.016092

Abstract A flame retardant composition was prepared by using phosphoguanidine, guanidine sulfamate, disodium octaborate tetrahydrate and dodecyl dimethyl benzyl ammonium chloride. Veneers were immersed in such flame retardant mixture to prepare plywood. The combustion characteristics and thermal stability of plywood were assessed using a cone calorimeter and TG. Results showed that: (1) High concentration and loading of flame retardant were beneficial for the fire resistance of the plywood. (2) The limiting oxygen index (LOI) and residual mass of plywood processed using the flame retardant was increased by 87.52% and 58.66% compared to those of the untreated plywood, while the average heat… More >

Hang Xu, Huiling Du^*, Le Kang, Qiudi Cheng, Danni Feng, Siyu Xia

Journal of Renewable Materials, Vol.9, No.12, pp. 2129-2141, 2021, DOI:10.32604/jrm.2021.016090

Abstract The large-scale accumulation and pollution of solid mining waste is an urgent issue. Coal gangue is a prominent type of solid waste, and shows promise for use in high value-added products due to its content of many important compounds, including SiO₂ and Al₂O₃. This study proposed the preparation of highly porous ceramics from coal gangue, coal slime, and coconut palm fibers. The ceramics were produced at a sintering temperature of 950°C with a fiber content of 6 wt%, which led to the formation of porous ceramics with a porosity of 66.93%, volume density of 1.0329 g/cm3 , compressive strength of… More > Graphic Abstract

Meifeng Wang^1,2, Wubliker Dessie², Hui Li^1,*

Journal of Renewable Materials, Vol.9, No.12, pp. 2119-2128, 2021, DOI:10.32604/jrm.2021.016811

Abstract Lignin is the most abundant heteropolymer based on aromatic subunits in nature. Large quantities of lignin are annually produced from pulping processes and biorefinery industries. Its unclearly defined structure and difficult biodegradation mainly limit its utilization. This work focused on the effect of hydroxylation of lignin on its microbial degradation. Butyloxy carbonyl-modified lignin, and hydroxylated-lignin were synthesized with di-tert-butyl dicarbonate and hydrogen peroxide, respectively, using lignin as raw material. The degradation of the modifiedlignins both by P. chrysosporium and B. subtilis were analyzed using UV-vis spectroscopy. Results revealed that the lignin degradation velocity raises with the increase hydroxylation level of… More > Graphic Abstract

Rumeng Li¹, Guozhu Zhan², Qi Ma¹, Yunhe Yang¹, Xiaoyun Liu^1,*, Yitong Zhang¹, Qixin Zhuang¹

Journal of Renewable Materials, Vol.9, No.12, pp. 2093-2117, 2021, DOI:10.32604/jrm.2021.015827

Abstract To explore the influence of substituent groups on thermally induced curing, eight new bio-based benzoxazines containing different substituent groups with different electron negativity and volumes were synthesized. The thermal curing of these bio-based benzoxazines was studied in detail. Combined with the curing reaction kinetics, simulation and calculation of Highest Occupied Molecular and Lowest Unoccupied Molecular values, the spatial and electronic effects of different substituent groups on the curing of benzoxazine was explored. It was found that when the substituent was located at the position directly connected to the N atom, the steric hindrance effect of the group was dominant. When… More > Graphic Abstract

Qionglin Luo¹, Mingliang Wang², Hui Zhang¹, Yuejun Ouyang¹, Hongwei Lin¹, You Shu^1,*, Shengpei Su^1,2,*

Journal of Renewable Materials, Vol.9, No.12, pp. 2067-2076, 2021, DOI:10.32604/jrm.2021.016255

Abstract Poly(L-lactic acid) (PLLA) is a thermoplastic material with complete degradability, high biocompatibility and excellent mechanical properties. It can replace petroleum-based polymers are currently being used in the fields of packaging, agriculture, textiles, medical and so on. However, PLLA’s extremely flammability greatly limits its wider application. An bio-based flame retardant L-APP/PLLA composites was prepared by melt blending of the L-APP and PLLA. The morphology, impact properties, thermal properties and flame retardant properties of composites were investigated by field emission scanning electron microscope (SEM), impact tester, differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), limiting oxygen indexer (LOI) and horizontalvertical burning tester. The… More > Graphic Abstract

Lei Tan, Liangxian Liu, Chaodong Liu, Weihong Wang^*

Journal of Renewable Materials, Vol.9, No.11, pp. 1897-1911, 2021, DOI:10.32604/jrm.2021.016418

Abstract As the most favorable alternative to petroleum-based polymers, polylactic acid (PLA) which is the most promising degradable polymer has attracted increasing attention. However, the addition of cellulose to improve its strength often results in a reduction in its toughness. In this work, microscale cellulose is first prepared from pulp fibers by using a deep eutectic solvent, and then is used as the reinforcement of PLA. A microcrystalline cellulose (MCC)/PLA sheet with uniform texture is obtained by the solution mixing, melt blending, hot-pressing and cold-pressing process. The effects of MCC on the crystallization, thermal stability and mechanical properties of the PLA… More >

Zhigang Wu^1,#, Sicheng Chen^1,#, Jiankun Liang², Lifen Li¹, Xuedong Xi^3,4, Xue Deng¹, Bengang Zhang^3,*, Hong Lei^4,*

Journal of Renewable Materials, Vol.9, No.11, pp. 1959-1972, 2021, DOI:10.32604/jrm.2021.016786

Abstract Alkali lignin was processed by plasma and then used in modification of phenol formaldehyde resin in this study. Chemical structural changes of lignin which was processed by plasma as well as bonding strength, tensile property, curing performance and thermal property of the prepared phenol formaldehyde resin which was modified by the plasma processed lignin were analyzed. Results demonstrated that: (1) Alkali lignin was degraded after the plasma processing. The original groups were destroyed, and the aromatic rings collected abundant free radicals and oxygen-containing functional groups like hydroxyls, carbonyls, carboxyls and acyls were introduced into increase the reaction activity of lignin… More > Graphic Abstract

Xiaohua Gu^1,*, Shiwei Lyu¹, Siwen Liu²

Journal of Renewable Materials, Vol.9, No.11, pp. 1913-1926, 2021, DOI:10.32604/jrm.2021.015400

Abstract A bi-component alcoholysis agent containing propylene glycol (PG) and ethanolamine (ETA) was used to catalyst the degradation of the waste polyurethane rigid foam. The oligomer polyols obtained through degradation were used as raw materials to produce recycled polyurethane rigid foam composites with lignin as reinforcing filler. The effect of alcoholysis mass ratio on degradation was investigated by analyzing the viscosity, hydroxyl content and chemical structure of the degradation products. The effect of lignin addition on the properties of regenerated polyurethane rigid foam were investigated by analyzing water absorption rate, compressive strength, porosity, thermal stability, thermal conductivity coefficient, morphology and thermal… More >

Nataša Knez¹, Mirko Kariž², Friderik Knez¹, Nadir Ayrilmis^3,*, Manja Kitek Kuzman^2,*

Journal of Renewable Materials, Vol.9, No.11, pp. 1883-1895, 2021, DOI:10.32604/jrm.2021.016128

Abstract The effects of selected printing parameters on the fire properties of additively produced composites from neat polylactic acid (PLA) and wood/PLA filaments were investigated. The reaction to fire of the 3D-printed specimens was tested according to the ISO 5660-1 cone calorimeter test method. The results showed that the properties of the specimens when exposed to fire were significantly affected by the incorporation of wood flour into the PLA filament. It was also interesting that PLA specimens had much better reactions to fire than the wood/PLA specimens. Time to ignition was found to be much longer in the 3D-printed PLA specimens.… More >