Synthesis of absorbent polymer films made from fatty acid methyl esters,glycerol, and glutaric acid: Thermal,mechanical, and porosity analyses

In previous studies, monoglycerides (MGs) were incorporated into the matrix of poly(glutaric acid–glycerol) films to investigate their effect on the thermal, mechanical, and solvent absorption properties of the resultant films. In this study, the same properties were monitored when fatty acid methyl esters (FAME) were added to the polymer film formulation. Thermogravimetric analysis showed that, while the decomposition profile of the FAME and MG-infused films were different, the final decomposition temperatures were similar for both film types at approximately 400 °C. Degree of branching (DB%) was calculated from nuclear magnetic resonance data and was used to examine the effect of DB% on the mechanical and absorption properties of the films. Experimental results did not show any correlation with DB% and any of the physical, chemical, mechanical, or thermal properties studied. Relative to the poly(glycerol–glutaric acid) control, the incorporation of MG into the polymer matrix resulted in improved % absorption but decreased the mechanical property values. Conversely, adding FAME into the matrix improved the mechanical property values; however, there was no significant change in the % absorption values relative to the control. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47822.     

BaFe12O19@（CaO-CaAl12O19）磁性固体碱催化甘油制备碳酸甘油酯

以九水硝酸铁、硝酸钡为原料采用溶胶凝胶法得到BaFe_(12)O_(19)前驱体,焙烧浸渍勃姆石溶胶后分散于Ca(NO_3)_2·4H_2O溶液,采用沉淀法合成了磁性固体碱催化剂BaFe_(12)O_(19)@(CaO-CaAl_(12)O_(19))。对其进行了磁滞回线、X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电镜(TEM)、CO_2-TPD表征。将制得的磁性固体碱催化剂应用于甘油和碳酸二甲酯的酯交换反应,考察反应条件对产物收率的影响。结果表明:催化剂有较强的碱强度且活性位包裹均匀、有较好的磁性;在m(Ca(NO_3)_2·4H_2O)∶m(BaFe_(12)O_(19)@AlOOH)=5∶1、反应温度85℃、反应时间2.5 h、n(甘油)∶n(碳酸二甲酯)=1∶5、催化剂用量5%条件下,甘油转化率达到99.43%,碳酸甘油酯收率达到99.38%。     

Controlled release of fluorouracil (5-FU) from chitosan-co-poly(ethylene glycol)/ poly(glycerol sebacate)-co-poly(ethylene glycol)-coated iron oxide

A blend of polyglycerol sebacate-poly ethylene glygol/chitosan-poly ethylene glycol-coated iron oxide (PGS-PEG/CS-PEG@Fe₃O₄) nanoparticles for 5FU delivery was prepared by reverse ultrasonic emulsification method. To enhance polymers’ solubility, PEG was grafted. Chemical characterization was performed through Fourier transformed infrared and proton nuclear magnetic resonance spectra. In vitro assay revealed that release profile of 5FU-loaded PGS-PEG/CS-PEG@Fe₃O₄ is sustained. Moreover, cytotoxicity was analyzed on HT29 cell line at the presence of external magnetic field using the lactate dehydrogenase and Alamar Blue. Results illustrate that (PGS-PEG/CS-PEG@Fe₃O₄) is promising to use as a carrier for 5FU anticancer agent with sustained tailored release.     

水分含量对不同类型加热不燃烧卷烟化学成分的影响

为探讨水分含量对不同类型加热不燃烧卷烟化学成分的影响,以稠浆法薄片制备卷烟A和造纸法薄片制备卷烟B为研究对象,开展烟支水分与甘油、烟碱相关性研究,并进行扫描电镜和热重分析。结果表明:①烟草薄片中甘油、烟碱质量含量以干薄片中相应物质质量含量表述更准确。②烟气水分释放量、烟气粒相物重量与烟支含水量呈正比,粒相物水分含量为53.33%～65.89%。③受烟支加热温度及烟草薄片性质的影响,卷烟A烟气甘油释放量与烟支含水量呈正比,卷烟B烟气甘油释放量与烟支含水量呈反比,但两者烟气烟碱释放量均为50%湿度平衡后的烟支最高。另外,卷烟A的烟气中水分、甘油、烟碱转移率均显著高于卷烟B的。     

生物甘油基聚酯对大豆分离蛋白复合膜贮藏期间机械性能稳定性的影响

以大豆分离蛋白(soybean protein isolate,SPI)为主要原料,将甘油进行改性后制备的生物甘油基聚酯加入到成膜液中制备SPI复合膜,通过对贮藏期间SPI复合膜机械性能、水分含量和甘油迁出率进行跟踪测定,比较分析甘油经改性后制备的增塑剂对SPI复合膜的机械性能稳定性、保水性、甘油迁出率稳定性及微观结构的影响。研究结果表明:与未改性甘油增塑的SPI复合膜相比,改性后制备的机械性能稳定性最高的SPI复合膜为生物甘油基聚酯(生物聚甘油和脂肪酸的质量比为1∶1)增塑的复合膜,其拉伸强度稳定性提高了18.08%,断裂延伸率稳定性提高了34.52%,水蒸气透过系数稳定性提高了14.68%,水分含量稳定性提高了17.02%,甘油迁出率稳定性提高了74.28%,膜体系的紧密性和连续性增强,且其表面形成了致密的空间网状结构。生物甘油基聚酯的添加一定程度上提高了SPI复合包装薄膜的机械性能稳定性,为其更广泛的实际应用提供了重要的理论参考和技术支持。     

甘油直接制备丙烯醇的催化剂和反应工艺研究进展

丙烯醇是一种十分重要的中间体和化学原料。近年来，以甘油为原料直接制备丙烯醇的研究引起了许多科学家的关注。本文参考了最近十年来发表的文献，详细介绍了均相甲酸诱导的甘油脱氧脱水反应、催化剂作用下的甘油脱氧脱水反应、液固相甘油氢解反应和气固相甘油氢转移反应等过程制备丙烯醇的相关工艺、反应机理和催化剂的研究进展及发展趋势，并对比了上述工艺的优缺点。其中，均相甲酸诱导的甘油脱氧脱水工艺比较成熟，已经在实验室中得到验证和应用，但是甲酸的消耗量大，整个过程的原子经济性很差。 甘油脱氧脱水反应和液固相甘油氢解反应不仅需要采用价格昂贵的铼基催化剂，而且丙烯醇的选择性较低。 铁基催化剂作用下的气固相甘油氢转移反应制备丙烯醇，由于催化剂的价格低廉、制备工艺简单、产品分离容易等优势而备受关注，是最近五年的研究热点。在文献基础上，认为今后研究应该重点关注催化剂的酸碱性、氢转移能力及其与速率控制步骤的匹配，并有针对性地对催化剂进行优化和改进。     

The growth of oleaginous Rhodotorula glutinis in an internal-loop airlift bioreactor by using mixture substrates of rice straw hydrolysate and crude glycerol

The conversion of lignocellulosic biomass (LCB) to microbial oils is attracting a growing amount of attention. However, the growth of the oleaginous yeast Rhodotorula glutinis on LCB hydrolysate (mainly rice straw) only will lead to a low lipid mass fraction, in the range of 10–20%. This study shows that the addition of crude glycerol to the LCB hydrolysate medium can efficiently raise the lipid mass fraction to the range of 30–40%. Crude glycerol is a by-product in the biodiesel production process. The use of renewable LCB hydrolysate and crude glycerol would greatly reduce the substrate cost for microbial oil production using R. glutinis. In addition, the results of experiments show that a low-cost airlift bioreactor is a more suitable fermentation process for the growth of R. glutinis than the use of a conventional agitation tank. When using mixed carbon sources of LCB hydrolysate with 30 kg m⁻³ of reducing sugars and 30 kg m⁻³ of crude glycerol, a maximal cell mass of 21.4 kg m⁻³ and lipid mass fraction of 58.5 ± 6.2 were achieved in an internal loop airlift bioreactor, and this process may have the potential to be applied in scale-up production.