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1.
The objective of this work is to prepare a hyperbranched polyethylenimine (HBPEI) grafted activated carbon obtained from waste fiberboard for effectively removing Cr(VI) from aqueous solution. The waste fiberboard activated carbon (WFAC) was modified by HBPEI and cross-linked with glutaraldehyde (GA). The optimal modified conditions were as follows: HBPEI molecular weight 10,000 g/mol, HBPEI/WFAC (w/w) 0.5, GA concentration 0.25%, reaction time 60 min. Both pristine WFAC and HBPEI–WFAC were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), Scanning electronic microscopy (SEM), and Roman spectra. XPS data showed the obvious increase in nitrogen (from 0.72% to 6.65%) after modification. The results of FTIR and XPS suggested that HBPEI was chemically bonded onto the WFAC by the glutaraldehyde (GA) between the amine groups of WFAC and that of HBPEI. HBPEI was also probably grafted onto WFAC through the intermolecular interaction between the carboxylate groups of WFAC and the amine groups of HBPEI. However, the BET surface area of modified WFAC declined slightly (about 200 m2/g). The ID/IG of modified WFAC decreased from 0.92 to 0.82, which indicated that the modification process had no significant effect on the graphitization of activated carbon. The adsorption property onto HBPEI–WFAC and the factors containing contact time, pH value, and Cr(VI) concentration were also investigated. Analysis of the Cr(VI) adsorption data was well simulated by the pseudo-second-order kinetic model and Langmuir adsorption isotherm model, and maximum Cr(VI) uptake of HBPEI–WFAC was 500 mg/g. 相似文献
2.
The improving effects of addition of nano-wollastonite on some fire properties of medium-density fiberboard (MDF) were studied in this work. Nano-wollastonite was added at four levels (2%, 4%, 6%, and 8%). The size range of at least 70% of nano-wollastonite particles were 30 to 110 nm. The results showed statistically significant improving effect of nano-wollastonite on time to onset of ignition. The improving effect was primarily attributed to an increase in thermal conductivity of board containing nano-wollastonite. This increase in turn resulted in better curing of resin, and a higher integrity of fibers thereof. Moreover, nano-particles provided a surface with reduced combustibility and therefore, penetration of fire to the inner layers of boards was delayed, thus improving fire properties. High and significant correlations were found between thermal conductivity coefficients of boards with different fire properties. It was concluded that for applications where fire properties are of prime importance, nano-wollastonite content of 8% can be recommended. Moreover, further studies are needed to compare and standardize the results obtained from the apparatus used here with those obtained from internationally recognized apparatuses like cone calorimeter. 相似文献
3.
详细地介绍了中密度纤维板干燥前与干燥后组合施胶系统技术原理、技术优势及其在生产线上的实际应用,详细地分析了应用过程存在的主要问题及其产生原因,并对其后续使用提出了建议。 相似文献
4.
五层瓦楞纸板与原纸强度关系的研究 总被引:4,自引:3,他引:1
通过试验,研究了五层瓦楞纸板强度与原纸强度的关系,利用SAS软件对试验结果进行分析,得出五层瓦楞纸板边压强度和耐破度计算的回归方程.该方程可以为瓦楞纸板强度的预测和纸板的配纸提供计算依据. 相似文献
5.
为了降低传统脲醛树脂中甲醛的危害,采用了果糖代替甲醛与尿素合成了环保型果糖/尿素树脂,并用合成出的树脂与芦苇纤维复合制备了芦苇纤维板,考察了树脂合成过程中果糖/尿素物质的量之比、反应温度、反应时间、催化剂种类等工艺参数对树脂及芦苇纤维板性能的影响,得到了果糖/尿素树脂的最佳合成工艺,即果糖/尿素/催化剂盐酸的物质的量之比为2.5/1/0.13、反应温度为91℃、反应时间为3 h。在此最佳合成工艺下合成的树脂固含量为65.57%、黏度为73 m Pa·s,由此树脂制备的芦苇纤维板的静曲强度为26.19 MPa,弹性模量为6.13 GPa,完全满足国家标准GB/T 11718–2009的要求。 相似文献
6.
Advanced treatment of biologically treated medium density fiberboard (MDF) wastewater with Fenton and Fenton enhanced hydrodynamic cavitation process 下载免费PDF全文
7.
国家新标准《中密度纤维板》已正式发布实施。本文试图对新旧标准的主要内容变化进行比较,并着重对部分修订内容进行探讨分析,旨在质检部门、企业及相关部门能加强对新标准的理解,同时也为完善国家检测标准提供一定的参考依据。 相似文献
8.
9.
Abstract The objective of this preliminary study was to partially replace phenol in the synthesis of phenol-formaldehyde resin with feather protein. Feather protein–based resins, which contained one part feather protein and two parts phenol, were formulated under the conditions of two feather protein hydrolysis methods (with and without presence of phenol during hydrolysis), two formaldehyde/phenol molar ratios (1.8 and 2.0), and three pH levels (9.5, 10.5, and 11.5). Southern pine fiberboard bonded with feather protein–based resins was fabricated and bending strength, bending stiffness, internal bonding strength, and percent thickness swell were evaluated. Results indicated that the test parameters all significantly affected resin quality. The resin formulated with feather protein hydrolyzed in the presence of phenol, using a F/P ratio of 2.0, and at a pH of 10.5 performed as well as the neat PF resin. Based on our findings, feather protein is a potential cost-effective material for the production of PF-type adhesive resins. 相似文献
10.
对中型中密度纤维板生产中造成环境污染的污染源、污染因子进行了分析研究,根据同类企业实际运行情况提出了治理途径和解决措施。 相似文献