Acid violet 6B as a novel corrosion inhibitor for cold rolled steel in hydrochloric acid solution

The inhibition effect of acid violet 6B (AV6B) on the corrosion of cold rolled steel (CRS) in 1.0–5.0 M HCl solution was studied for the first time by weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) methods. The results show that AV6B is a very good inhibitor in 1.0 M HCl, and the adsorption of AV6B on CRS surface obeys Langmuir adsorption isotherm. Polarization curves reveal that AV6B behaves as a mixed-type inhibitor. EIS spectra exhibit one capacitive loop and confirm the inhibitive ability. Effects of immersion time and acid concentration on inhibition performance were also discussed.     

云南甜龙竹竹叶提取物在盐酸中对钢的缓蚀作用

云南甜龙竹竹叶提取物（DBLE）可作为一种环境友好型植物缓蚀剂,用红外光谱（FTIR）表征了DBLE的主要官能团。采用失重法、动电位极化曲线、EIS和SEM研究了 DBLE在1.0 mol/L HCl溶液中对冷轧钢的缓蚀作用。结果表明：DBLE具有良好的缓蚀作用,最大缓蚀率达93%,且在钢表面的吸附符合Langmuir吸附等温式。通过Van't Hoff方程和Arrhenius公式分别求出了吸附热 Δ H_ads和表观活化能E_a,并据此讨论了缓蚀作用机理。DBLE为混合抑制型缓蚀剂;EIS谱呈半圆容抗弧,电荷转移电阻随缓蚀剂浓度的增加而增大。SEM再次表明DBLE 对钢具有好的缓蚀作用。     

Comparing two intermittent drying schedules for timber drying quality

Intermittent drying techniques for drying timber may provide various benefits by improving timber quality and addressing energy efficiency through saving in energy consumption. The purpose of this study was to compare two intermittent drying schedules applied in the treatment of Eucalyptus delegatensis boards, through assessing surface and internal check development, moisture content (MC) profiles during drying, and timber distortions at the end of drying. The study used identical conditions during the heating phase at 45°C/60% relative humidity (RH), except for RH during the nonheating phase (80 and 90%). The results, discussed in this paper, analyzed the timber quality during and at the end of drying. The different RH during the nonheating phase did not generate a significant difference in MC at the case boards between the two drying schedules. The assessed quality of timber at the end of drying was based on AS/NZS 4787:2001. MC gradient, drying stress residual, internal checking and collapse were graded as class “A” (class A is the highest grade and D is the lowest). Bow, cupping, and spring were under the permissible levels based on grading standard AS 2082–2007. Measured data were validated using Drytek® simulation software showing MC movement in case boards.     

Effects of Seed Coat on Oxidative Stability and Antioxidant Activity of Apricot (Prunus armeniaca L.) Kernel Oil at Different Roasting Temperatures

Apricot kernels were roasted at various temperatures (120–180 °C) for 10 min and changes in the fatty‐acid profiles, oxidative stability, and antioxidant activity, as well as the total phenolic contents (TPC) of the oils and skin (seed coat), were monitored. Roasting has no obvious influence on profiles and contents of fatty acid, induction period (IP), browning index, TPC, and antioxidant activity (2,2‐diphenyl‐1‐picrylhydrazyl (DPPH), 2,2‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid), (ABTS) and Oxygen Radical Absorbance Capacity (ORAC) of oils obtained from apricot naked‐kernel, but increases IP, TPC, and oxidative stability in oils obtained from apricot kernel with skin. All results in the present work demonstrated that thermal treatment accelerated the production and transference of alcohol‐soluble phenolics into the oil, and improved the oil oxidative stability. It is not Maillard reaction products but alcohol‐soluble phenolic compounds in skins that play a role in improving the oxidative stability and antioxidant activity of oils, and inhibition for primary peroxide production was more effective than secondary peroxide production at a low roasting temperature and a short roasting time. The present findings can advance knowledge on the conditions used for utilization of coproducts (skin) of apricot kernel and facilitate large‐scale production of stable oil against oxidation.     

基于木素填料的脲醛树脂胶粘剂研究

研究了面粉、碱木素和木素磺酸钙对脲醛树脂(UF)胶粘剂性能的影响,探讨了碱木素、木素磺酸钙用作胶粘剂填料的可行性。研究结果表明:UF胶粘剂的固含量随着填料用量的增加而增大;UF胶粘剂的固化时间和pH值随面粉或木素磺酸钙用量的增加而降低,却随碱木素用量的增加而增大;使用含木素填料的UF胶粘剂压制胶合板,当w(木素)=15%～20%、施胶量为240～260g/m2时,胶合板的湿态胶合强度略高于纯UF胶粘剂压制的胶合板;以m(面粉)∶m(木素)=1∶1作为混合填料,其干态胶合强度远高于国家标准,并且均高于1.05MPa,其湿态胶合强度能达到国际标准。     

两性聚丙烯酰胺的性质、合成与应用研究进展

两性聚丙烯酰胺属于两性聚电解质,是一种新型功能高分子。本文首先阐述了两性聚丙烯酰胺的结构和特性,包括等电点、电荷密度、分子链形态、浊度、黏度、吸附特性等;接着概括了目前较为普遍的两性聚丙烯酰胺的合成反应,包括大分子改性、接枝共聚、阴/阳离子单体共聚,以及丙烯酰胺与甜菜碱型单体共聚;还总结了两性聚丙烯酰胺的合成方法,包括:水溶液聚合、反向乳液聚合、反向微乳液聚合、悬浮聚合、辐射聚合等;最后总结了其在各领域的应用,尤其是在造纸工业中的助留助滤和纸张增强等应用。     

葛根淀粉基胶黏剂制备与性能研究

研究开发以淀粉为主要原料的环保型胶黏剂替代"三醛类"木材胶黏剂,对彻底解决人造板及其制品的甲醛释放问题具有重要意义。以野生葛根淀粉为原料,通过降黏处理,并与聚醋酸乙烯酯和异氰酸酯复配,制备出胶合强度达到国家Ⅱ类要求的淀粉基木材胶黏剂。研究了降黏剂用量、降黏时间、聚醋酸乙烯酯和异氰酸酯用量对淀粉基木材胶黏剂胶合强度的影响。优化工艺条件下制备胶黏剂胶接胶合板的胶合强度为1.89 MPa,能够满足国家Ⅱ类胶合板强度要求。     

Microbial polymers in the aquatic environment—I: Production by activated sludge microorganisms under different conditions

Soluble waste products of activated sludge microorganisms were prepared under different conditions. After being concentrated by vacuum distillation, the polymers with molecular weights above 10,000 were isolated by dialysis and lyophilization. The lyophilisates, the COD of which amounted to 36–62% of the total COD in the original liquid samples, were hydrolysed with HCl under various conditions. All isolated polymers contained sugars, amino sugars, uronic acids and amino acids, which indicates their heteropolysaccharidic character. They were formed both during growth and during the starvation and decomposition of microorganisms. Biodegradability tests confirmed that the polymers are refractory with the BOD rate constant of 0.03-0.04d⁻¹. The possible reasons for their production are discussed.     

硝酸镧、硝酸铈在HCl介质中对铝的缓蚀作用

用失重法和动电位极化曲线法研究了1.5 mol/L HCl中,两种稀土盐硝酸镧和硝酸铈对铝的缓蚀作用.实验结果表明:在盐酸溶液中,两种稀土盐均对铝具有较好的缓蚀作用;缓蚀率排序为:La(NO3)3＞Ce(N03)3.在同等条件下,通过对比实验发现两种稀土硝酸盐均比它们的阳离子盐(LaCl3、CeCl3)和阴离子盐(NaNO3)表现出较好的缓蚀作用.动电位极化曲线表明,硝酸镧和硝酸铈在HCl中为阴极抑制型缓蚀剂.     

Durable nanocomposite adhesives based on polyacrylates and surface-modified colloidal silica

Surface-modified colloidal silica (M-CS) nanoparticles were successfully synthesized from colloidal silica (CS) and methyltrimethoxysilane using sol–gel method and characterized by Fourier transform-infrared spectroscopy. Both CS and M-CS were then incorporated into acrylic adhesives. M-CS particles in 2-ethoxyethanol had similar particle size to pure CS based on the characterization by DLS. The morphologies of M-CS particles in acrylic adhesives examined by TEM showed more homogeneous dispersities than that of pure CS which were aggregated and phase separated in acrylic adhesives. In addition, the thermal properties of the nanocomposite acrylic adhesives determined by thermogravimetric analyses and differential scanning calorimetry showed higher glass transition temperature and thermal properties than pure acrylic adhesives. Finally, the 180° peel strength of nanocomposite acrylic adhesives was higher than pure adhesives with improved durabilities.