Effect of structure on the properties of polyurethanes based on aromatic cardanol-based polyols prepared by thiol-ene coupling

Industrial-grade cardanol and 2-mercaptoethanol were reacted to generate hydroxyl-functionalized cardanol by UV, free-radical-initiated thiol-ene coupling between the double bond moieties of the cardanol long carbon side chain and thiol functional groups. The average hydroxyl number of the hydroxyl-functionalized cardanol was controlled by reaction time, with the hydroxyl values of this ranging within 168–201 mg KOH g⁻¹. This cardanol was then used as a polyol to prepare cardanol-based polyurethane with hexamethylene diisocyanate and a NCO/OH ratio of 1. To compare the effect of cardanol-based polyols with the properties of cardanol-based polyurethane, cardanol modified with 10-undecylenate was used as a raw material to prepare cardanol-based polyols, including the long carbon chain of 10-undecylenate. All properties were examined, and data revealed that cardanol-based polyols including this long carbon chain can improve the hydrophobic and mechanic properties of the cardanol-based polyurethane.     

Preparation and polymerization of isopimaric acid derivatives

Isopimaric acid is a typical rosin compound and can account for 30% of the total mass of slash pine rosin. The molecular structure of isopimaric acid derivatives features an unsaturated double bond at the C13 position, opening up the possibility of their industrial polymerization. In this study, isopimaric acid (95.4%), methyl isopimarate (99.5%), and allyl isopimarate (95.1%) were prepared as highly pure monomers. New experimental results are presented and mechanisms based on the investigation of free-radical polymerization under UV irradiation are proposed. New rosin monomers for potential value-added utilization of woody biomass are also identified. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47817.     

衣康酸光固化树脂的研究进展

被誉为"绿色技术"的光固化技术,不仅节能环保而且经济高效,已在众多领域得以应用。利用天然可再生资源制备光固化树脂对光固化技术的可持续发展具有重要意义。衣康酸作为一种来源广泛的天然可再生资源,其分子结构中同时含有不饱和双键和两个羧基,可替代丙烯酸、己二酸等石化资源合成各种光固化不饱和树脂,所得树脂综合性能优良。本文综述了衣康酸制备光固化树脂的研究进展,主要包括环氧衣康酸树脂、衣康酸聚酯、衣康酸聚酯丙烯酸酯、衣康酸聚氨酯丙烯酸酯等。由衣康酸合成的光固化树脂在涂料、生物医药和3D打印材料等领域具有重要的应用价值,为生物质资源的高值化利用提供了新途径。     

The effect of dense polymer brush on the microfibrillated cellulose for the mechanical properties of poly(ε-caprolactone) biocomposites

Two different cellulosic fibers [pristine microfibrillated celluloses (MFCs) and 2,2-bis(hydroxymethyl)propionic acid-modified MFCs (bis-MPA-modified MFCs)] were grafted by poly(ε-caprolactone) (PCL) molecules through the ring-opening polymerization (ROP) method. The PCL-grafted MFCs were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and elemental analysis. The results showed that the grafting of PCL on the bis-MPA-modified MFCs was more efficient than that of the pristine MFCs due to the higher density of the activated hydroxyl groups on the bis-MPA-modified MFCs. Furthermore, the numerous PCL chains bound to the bis-MPA-modified MFCs (PCL-g-mMFC) demonstrated the stronger interfacial adhesion between the modified MFC fibers and the PCL matrix, as well as the greatly improved dispersion of the modified MFCs in the PCL matrix of the PCL/cellulose biocomposites.     

紫外法和皮粉法测定塔拉单宁含量的对比研究

分别采用紫外法和皮粉法对5种不同含量的塔拉单宁进行对比研究,并利用SPSS软件对单宁含量测定结果进行显著性检验,结果表明：高纯度塔拉单宁（93%）分别用紫外法和皮粉法测定单宁含量时实验结果并未显著差异（P>0.05）,而4种纯度为60%左右塔拉单宁的实验结果均具有显著性差异（P < 0.05）,皮粉法测得的单宁含量均比用紫外法测得的结果高,差值约为1.5%~2.0%,并由此计算出紫外法测定塔拉单宁含量计算公式中的矫正常数p为1.03。紫外-可见吸收光谱与HPLC分析结果表明：塔拉单宁与五倍子单宁的最大吸收峰均为276 nm,同质量浓度下塔拉单宁的吸收峰强度高于五倍子单宁,塔拉单宁成分出峰时间主要在20~40 min,五倍子单宁主要在30~45 min。     

林业资源热解气化供热发电产业发展趋势与战略对策

生物质热解气化供热发电是林业资源加工剩余物高效综合利用产业。我国林业加工废弃物可利用量约为2.1亿吨/年,利用可再生林业资源供热和发电,有助于改善我国能源结构,增强能源安全保障,提升我国节能减排水平,推动社会主义新农村建设,促进林业可持续发展。针对目前林业资源气化供热发电产业发展过程中普遍存在的原料收储运存在瓶颈、生产过程自动化和智能化水平不高、标准化生产技术不成熟、高值化和综合利用技术缺乏等问题,建议加强林业特色资源林基地建设、创新分布式产业发展模式、突破卡脖子技术难题、严格市场准入审批、加强政府管理和行业规范、加大政策扶持力度,力争建立原料供应稳定、高品质燃气绿色制造和生物炭高效应用的一体化产业体系,到2035年气化产业年利用林业剩余物超过500万吨标准煤,总产值达100亿元/年。     

酚醛树脂胶粘剂研究进展

酚醛树脂胶粘剂具有优良的耐水性、耐热性、耐候性,粘接强度高及化学稳定性好等优点而被用于诸多领域。但是其还存在固化温度高、热压时间长、易透胶、有甲醛释放、原料成本高且不可再生等缺点。综述了快速固化和低游离甲醛含量酚醛胶粘剂,三聚氰胺、尿素、木质素、生物质焦油以及其他改性酚醛树脂胶粘剂,并对其存在问题和发展前景作了分析和展望。     

PLA/橡实淀粉/二聚脂肪酸聚酰胺复合材料研究

采用熔融挤出法制备了聚乳酸(PLA)/橡实淀粉(AS)/二聚脂肪酸聚酰胺(DAPA)三元复合材料。在保持PLA与AS质量比不变的情况下(60/40),研究了DAPA含量对复合材料的力学性能、疏水性能、热性能和熔体流动速率(MFR)的影响。研究表明,随DAPA添加量的增加,复合材料的疏水性和MFR逐渐提高,而复合材料的拉伸、弯曲强度呈先增大后减小的趋势,且当DAPA质量分数为2%时,复合材料具有最优的力学性能;DAPA的加入增强了PLA与AS的界面相容性,但在一定程度上降低了复合材料的玻璃化转变温度和初始热稳定性。     

活性炭吸附回收VOCs技术的研究进展

详细介绍了活性炭吸附回收VOCs的技术研究过程以及研究进展,分析了吸附剂的制备与改性、吸附过程的影响因素及数学模型、脱附方法等内容,并指出了存在的问题。在总结现有研究进展的基础上,对活性炭吸附回收VOCs技术的研究重点进行了预测和展望。     

松香及其改性产品在助焊剂中的应用现状

综述了国内外用于助焊剂中的多种松香产品及其特性,包括松香、精制松香、氢化松香、歧化松香、聚合松香、松香多元酸、松香酯以及松香胺等,并展望了在助焊剂领域松香改性研究的前景。