Curing behavior and mechanical behavior of fully and semi-interpenetrating polymer networks based on polyurethane and acrylics

Polyurethane (PU) was made by reacting stoichiometric equivalent of trimethylol propane (TMP) and desmodur L. Fully interpenetrating polymer networks (fully IPN's) of various compositions based on PU and poly(ethylene glycol) diacrylate (PEGDA) were prepared by blending various ratios of PU/PEGDA, and cured by benzoyl peroxide (BPO). Semi-interpenetrating polymer networks based on PU and poly(ethylene glycol) monomethyl ether of acrylate (PEGMEA) were prepared in a similar way. Shift of exothermic peaks during IPN formation were examined with dynamic DSC. Viscosity increases were investigated with a Brookfield RVT type viscometer. Dynamic mechanical properties were probed via a rheometric dynamic spectroscopy (RDS).Expermintal results revealed a good compatibility of both IPN systems, as evidenced from the single damping peak of the RDS curves for each composition. Shifts of exothermic peaks to higher temperatures during the formation of fully IPN were observed, especially for the composition of PU/PEGDA = 50/50, which showed an exothermic peak at the highest temperature. Experimental results also revealed delayed viscosity increases and decreased gel fractions for all fully IPN's. On the contrary, the semi-IPN did not exhibibt similar phenomena. All these findings supported an effect of network interlock during fully IPN formation. The existence of a network not only provided a sterically hindered environment, but also restrained the chain mobility of the growing network, and vice versa, thus retarding the curing rates of both networks. Network interlock also broadened the width of the half damping peak, T_1/2, and subsequently led to improved mechanical properties such as the impact resistance and Young's modulus of fully IPN material.     

大分子相容剂在填充聚烯烃中的应用

综述了国内外大分子相容剂在填充聚烯烃塑料中的应用，以及大分子相容剂改性填充聚烯烃塑料的物理与力学性能；指出大分子相容剂用于填充塑料，能改善高分子基体与填料间界面粘结，提高填充塑料复合材料的物理与力学性能，比传统有机偶联剂更具特点。     

催化偶联法合成2-氰基-4''''-甲基联苯的工艺研究

用对氯甲苯和镁粉在微量碘引发下反应制得的格氏试剂对甲苯基氯化镁和邻氯苯腈在二氯化锰的作用下经催化偶联,得到制备沙坦类抗高血压药物的中间体2-氰基-4’-甲基联苯,通过正交实验法筛选出最佳工艺条件,收率82.9%。     

溶剂对全氟磺酸再铸膜性能的影响

将氯碱工业用过的废离子交换膜放入乙醇水溶液中，在250℃和10MPa条件下溶解4h，固液分离后，得到，浓度为7．2％的全氟磺酸离子交换树脂（PFSI）溶液。并分别利用高沸点溶剂（HBPS）——二甲基亚砜（DMSO）、乙二醇（EO）、吡硌烷酮（NMP）和二甲基甲酰胺（DMF）置换其中的低沸点溶剂，采用浇铸法制备了再铸全氟磺酸质子交换膜。通过测定再铸膜（RCM）的交换容量、电导率、抗拉强度和X射线衍射谱图等研究了浇铸温度、浇铸时间和HBPS种类等条件对RCM性能的影响。结果显示：RCM的最佳成膜温度和时间分别为140℃和2h，温度高于180℃，部分PFSI开始分解，电导率和离子交换容量有所下降，时间低于2h，HBPS不能完全从RCM中挥发，RCM的机械强度和稳定性低。HBPS的种类和加入比例影响RCM的结晶程度和晶粒大小，HBPS加入量过少，在HBPS挥发完之前，PFSI没有足够的时间结晶，稳定性差，最好的HBPS是二甲基亚砜和吡硌烷酮，RCM与Nafion112具有相近的燃料电池性能。     

香茅醇的合成研究

用硼氢化钾与丙二酸生成的丙二酰氧基硼氢化钾在四氢呋喃中与二氢月桂烯反应制备香茅醇。在60℃下，反应6h时，反应100％发生在末端双键，且有90％以上的硼原子加成在末端双键的1位碳原子上。然后加入氢氧化钾溶液和用质量分数为30％双氧水继续反应，得到质量分数大于90％的香茅醇，在该条件下没有发现酮生成。     

复合高铁酸盐在焦化废水脱色中的应用研究

复合高铁酸盐用于处理经生化处理后不能达标的焦化废水的深度脱色处理，废水色度可从80降至25以下。复合高铁酸盐脱色的适宜条件为：复合高铁酸盐浓度1.7mg／L，溶液pH值3．5～7.0，反应时间30min，反应温度室温。     

酚醛树脂为原料制备双电层电容器用电极材料的工艺研究

以酚醛树脂为原料，NaOH为活化剂制取双电层电容器用高比表面积活性炭电极材料，考察了炭化温度、活化温度、活化剂用量、活化时间等工艺参数对活性炭比电容的影响。实验结果表明，在炭化温度为600℃，活化温度为900℃，碱炭比为4，活化时间为1h的工艺条件下，制得的高比表面积活性炭比电容可达58．8F／g，用它组装成的电容器具有良好的充放电性能和循环性能，既能在大电流下快速充放电也能在小电流下缓慢充放电，但存在微孔所占比例较高引起的分散电容效应，这是大电流下放电容量有所下降的主要原因。     

Longitudinal and temporal water temperature patterns in the Yangtze River and its influence on spawning of the Chinese sturgeon (Acipenser sinensis Gray 1835)

In this study, water temperature longitudinal and temporal patterns were investigated in four locations of the Yangtze River to identify their influence on spawning of the Chinese sturgeon (Acipenser sinensis Gray 1835). The results showed that, historically (1960–1980), the four locations, Pingshan (PS, 2,687 river kilometres [rkm]), Yichang (YC, 1,640 rkm), Chenglingji (CLJ, 1,265 rkm), and Hukou (HK, 805 rkm), all had similar average annual water temperatures (around 18.0 °C) but very different amplitudes: The upper two locations, PS (11.4–23.2 °C) and YC (9.1–25.9 °C), were relatively stable and had smaller amplitude than the lower two ones, CLJ (6.0–30.0 °C) and HK (5.9–30.8 °C). On the basis of the physiological effects for Chinese sturgeon, we defined three water temperature ranges: stressing (>23 °C), holding (23–20 °C), and spawning (20–16 °C). We found that the upper two locations with successful spawning of the Chinese sturgeon (PS and YC) had short or no stressing period but long holding and spawning periods. Currently (2013–2016), the impoundment of the Three Gorges Reservoir increases the time for water temperature decreasing to 20 °C at the current spawning ground (YC) in autumn, which increases the stressing and holding periods, and has significant negative impact on the spawning of Chinese sturgeon. Nonetheless, considering the very high stressing temperature and the short duration of the holding and spawning periods at CLJ and HK, we propose that YC is still the most suitable spawning location for the Chinese sturgeon.     

Continuous finite element schemes for a phase field model in two-layer fluid Bénard–Marangoni convection computations

In this article, we study a phase field model for a two-layer fluid where the temperature dependence of both the density (buoyancy forces) and the surface tension (Marangoni effects) is considered. The phase field model consisting of a modified Navier–Stokes equation, a Cahn–Hilliard phase field equation and an energy transport equation is derived through an energetic variational procedure. An appropriate variational form and a continuous finite element method are adopted to maintain the underlying energy law to its greatest extent. A few examples for Bénard–Marangoni convection in an Acetonitrile and n-Hexane two-layer fluid system heated from above will be computed to justify our phase field model and further show the good performance of our methods. In addition, an interesting experiment will be performed to show the competition between the Marangoni effects and the buoyancy forces.