Experimental research of drop‐on‐demand droplet jetting 3D printing with molten polymer

Three‐dimensional (3D) printing technology has become an effective method for parts manufacturing and got a certain application in many fields. Now, drop‐on‐demand droplet jetting 3D printing appears as a new method of manufacturing technology which has a proven research progress for metal, colloid, and liquid resin materials. However, there are hardly any researches of droplet jetting 3D printing with molten polymer. So, considering molten polymer as the jetting material with droplet jetting method is an explorative direction. In order to attain the molten polymer droplets and achieve droplet jetting 3D printing with molten polymer, the 3D printing technology of differential melt (3DPDM) is developed independently. According to 3DPDM, a complete set of drop‐on‐demand droplet jetting 3D printer have been developed. In this work, PP (6820) was chosen as the experimental material. Under the different print parameters such as the rotation speed of screw, nozzle diameter, mechanical impact frequency, heating temperature, the space between nozzle and platform, the form, and deposition of droplets were studied. Furthermore, the optimal print parameters were summarized. By printing models with the optimal print parameters, it turned out that the 3DPDM is able to achieve drop‐on‐demand droplet jetting 3D printing with molten polymer. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45933.     

Improved Second Generation Iron Pincer Complexes for Effective Ester Hydrogenation

Hydrogenation of esters to alcohols with a well‐defined iron ^iPr2PNP pincer complex has been recently reported by us and other groups. We now introduce a novel and sterically less hindered ^Et2PNP congener that provides superior catalytic activity in the hydrogenation of various carboxylic acid esters and lactones compared to the known complex. Successful hydrogenation proceeds under relatively mild conditions (60 °C) with lower catalyst loadings.

     

立式焦油氨水分离槽改进探讨

介绍了焦油氨水分离槽的操作参数和注意事项,针对生产操作存在的问题,提出了改进意见,对立式焦油氨水分离槽的改进和推广具有借鉴作用。     

实验数据在涂料领域专利申请中的重要性

从实验数据与说明书的充分公开,以及权利要求的创造性两方面分析实验数据在涂料领域专利申请中的重要性。     

水驱特征曲线法在技术可采储量标定中的应用——以鄂尔多斯盆地南部涧峪岔油田为例

水驱特征曲线法是针对水驱开发油田常用的一种可采储量计算方法。本文针对涧峪岔油田长期滚动建产、注水开发、产量稳定等特点,采用水驱曲线法标定油田技术可采储量。标定结果与油田开发现状匹配较好,对其他类似油田具有借鉴作用。     

Preparation and properties of gas barrier resin/rubber nanolaminated composites

An extremely high gas barrier resin was highly oriented and uniformly distributed in a rubber matrix layer by layer by the micro‐layer coextrusion technology and a special composite laminating device. The resulting composite had excellent gas barrier properties because of its alternating multilayer structure. Experimental tire samples were prepared and tested for high‐speed, endurance, and pressure performance. The results showed that because the barrier resin was evenly dispersed in the rubber matrix, the tire inner liner made of the composite showed excellent fatigue resistance and gas barrier performance. POLYM. ENG. SCI., 55:190–195, 2015. © 2014 Society of Plastics Engineers     

褐煤与秸秆共热解的研究

选用小麦秸秆与褐煤进行共热解实验。主要考察生物质掺混比对共热解产物及热解特征参数的影响。结果表明:生物质与煤具有不同的热解温度范围。从DTG曲线可知,共热解过程中生物质先于煤进行热解。随着生物质掺混比的增加,生物质的热解特征增强,且共热解产物收率与掺混比呈线性关系。因此可初步判断:在慢速热解条件下,生物质与煤在共热解过程中不存在协同作用。     

Mass transfer characteristics in a rotating packed bed with split packing

The rotating packed bed (RPB) with split packing is a novel gas–liquid contactor, which intensifies the mass transfer processes controlled by gas-side resistance. To assess its efficacy, the mass transfer characteristics with adjacent rings in counter-rotation and co-rotation modes in a split packing RPB were studied experimentally. The physical absorption system NH3–H2O was used for characterizing the gas volumetric mass transfer coeffi-cient (kyae) and the effective interfacial area (ae) was determined by chemical absorption in the CO2–NaOH sys-tem. The variation in kyae and ae with the operating conditions is also investigated. The experimental results indicated that kyae and ae for counter-rotation of the adjacent packing rings in the split packing RPB were higher than those for co-rotation, and both counter-rotation and co-rotation of the split packing RPB were superior over conventional RPBs under the similar operating conditions.     

超细h-BN粉在无水乙醇中分散工艺研究

通过测量超细h-BN粉Zeta电位,选用SA、OA、SDBS、PEG4000、PEG20000、Span80六种分散剂,系统研究了超声处理时间和分散剂浓度对超细h-BN粉在无水乙醇中分散性能的影响,并分析红外图谱探讨其分散机理.结果表明,超声时间和分散剂的浓度对分散效果有显著影响,随着超声时间和分散剂浓度的增加,超细h-BN粉分散稳定性先增大后减小;不同分散剂在最佳超声时间和浓度下,分散效果从高到低顺序依次为:SA＞ PEG4000＞ OA＞SDBS＞ PEG20000＞ Span80.推荐超细h-BN粉的最佳分散工艺为:在无水乙醇中添加粉体质量分数5 wt％的SA在超声功率为560W下超声20 min.