单线态氧与环境友好的纸浆漂白

简要介绍了单线态氧的性质、制备方法和应用领域,着重介绍了近期单线态氧用于纸浆漂白方面的有关研究和探索.相关研究表明,单线态氧对木素具有较强的降解能力,在漂白过程中具有较好的选择性,尤其是采用光催化法制备单线态氧用于纸浆的漂白,化学药品消耗少,对环境友好,进一步深入研究将具有广阔的应用前景.     

胶粘剂迁移定量分析方法的研究

本研究首次系统地对胶粘剂迁移的现代定量分析方法进行了研究,包括以Vr作丁苯胶乳的标记、用SEM-EDXA方法测定胶乳在涂层Z向的浓度和分布、用ESCA方法分析全胶粘剂在涂层表面的浓度.结果表明,该方法完全可以定量地分析描述胶粘剂在涂层中迁移的浓度分布和在涂层表面的浓度.     

Catalytic fast pyrolysis of waste pepper stems over HZSM-5

Catalytic fast pyrolysis over HZSM-5 of red pepper stems, a representative agricultural residue material in the southern area of South Korea, was carried out. The SiO₂/Al₂O₃ ratio of the catalyst were 23 and 280. Pyrolysis-gas chromatography/mass spectrometry was used to pyrolyze the pepper stem samples at 550 °C and directly analyze the product distribution. The main product species of the non-catalytic pyrolysis of pepper stems were phenolics, followed by oxygenates and acids. The production of aliphatic and aromatic hydrocarbons was marginal. On the contrary, catalytic pyrolysis over HZSM-5 reduced the fractions of phenolics and acids significantly, while considerably increasing the fractions of aliphatic and aromatic hydrocarbons. The catalytic activity of the HZSM-5 with a SiO₂/Al₂O₃ ratio of 23 was much higher, owing to its much larger amount of strong Brønsted acid sites, than the one with a SiO₂/Al₂O₃ ratio of 280. Conversion of carbohydrate via furans to aromatics over strong acid sites was observed, which was in good agreement with previous studies. This study suggests that the catalytic pyrolysis of lignin-rich biomass over acidic zeolite catalysts can be a promising method to produce valuable chemicals such as aromatic compounds.     

升华类热转印纸质量的影响因素

研究了热升华转移印花纸打印质量、转印质量、纸张形稳性的主要影响因素以及对原纸的性能要求,并对热升华转移印花纸的转印原理进行了分析讨论。结果表明：随着SiO2粒子粒径的减小和比表面积的增大,图像打印质量越来越好;原纸透气度越小,转印纸图像密度值就越高,转印质量越好。     

新型中浓打浆系统(MCPA-ZDPS)的研制及应用

阐述了MCPA-ZDPS新型中浓打浆系统装备的组成、结构、特点与中浓打浆的实现方式及生产应用效果。生产应用表明:在质量分数为6%～15%范围内,选用MCPA型中浓浆泵(质量分数为8%～15%)与ZDPS型中浓液压双盘磨浆机组成的中浓打浆系统装备能更好地实现中浓打浆,显著提高纸浆纤维的纤维细化效果,使纤维分丝帚化,增强纤维间的结合力,并能较好保留纤维长度,与传统的低浓双盘磨的打浆系统装备比,成纸物理强度指标提高20%～35%,能耗降低30%～40%。     

Carboxyethylated Microfibrillated Cellulose Fibers Prepared from Different Raw Materials

Carboxyethylation pretreatment was used to prepare microfibrillated cellulose(MFC)in this study.In order to evaluate the adaptability of this pretreatment method,carboxyethylated MFC was prepared from six different cellulosic materials.The carboxyl content,degree of polymerization,water retention value,charge density,chemical structure,size distribution,and micromorphology of the materials before and after pretreatment and grinding were studied and compared.The viscosity,ultraviolet(UV)transmittance,and thermal stability of the MFC samples at a certain concentration were determined.The results showed that the carboxyl content,water retention value,charge density,degree of polymerization,size distribution,and micromorphology of the pretreated and ground samples varied with those of the raw materials.The initial viscosity varied based on the type of raw material used.The MFC suspension prepared from cotton linter pulp had the highest UV transmittance,while the MFC prepared from bleached softwood kraft pulp had the highest viscosity at a low shear rate.After thermal degradation,the amount of residual char from the MFC prepared with the thermo-mechanical pulp was slightly higher than that of the other MFCs.This study demonstrates that carboxyethylation is an effective pretreatment method for different cellulosic materials.     

造纸法烟草薄片双辊表面涂布影响因素的研究

对烟草涂布液流变性能及影响造纸法烟草薄片双辊表面涂布效果的几个主要因素进行研究。研究表明,烟草涂布液在浓度为34.9%和41.2%之间出现黏度突然急剧增大的现象,且当浓度达到51.5%后开始析出固体小颗粒;抄造烟草基片时的压榨压力、基片的定量以及双辊涂布时的辊压对涂布率的影响较大,涂布机车速和涂布温度对涂布率的影响很小。