高分子材料导热性能影响因素研究进展

介绍了高分子材料导热性能影响因素研究进展，重点阐释了聚合物基体的结构特性（链结构、分子间相互作用、取向、结晶度等）、导热填料（种类、含量、形态、尺寸等）以及制备方法等对高分子材料导热性能的影响。     

Hetero-assembly of colloidal particles in concentrated non-aqueous suspensions by polymer dispersant design

Although many colloidal assembling systems have been reported, most systems suffer from severe aggregation under high solid concentrations, which can often be observed in typical hetero-aggregation system. In this study, we created a hetero-assembly system using concentrated (~50 vol%) suspensions by mixing large SiO₂ particles modified with polyacrylic acid partially complexed with oleylamine (PAA-OAm) and small SiO₂ particles modified with polyethyleneimine partially complexed with oleic acid (PEI-OA) in a non-aqueous solvent. We demonstrated that hetero-assembly is driven by the interactions between the uncomplexed carboxyl/amine groups of the PAA/PEI present on the particles, while severe aggregation is simultaneously prevented by the steric repulsions of the aliphatic oleyl chains. Comparison of the cross sections of the in-situ solidified hetero-assembled suspensions with those of ideally assembled structures which were reproduced by a simulation considering the statistical distribution of particles strongly supported successful particle assembling via the proposed approach. The results revealed that the OA content in the PEI-OA complex was the dominant factor that controlled the dispersion and assembling state of the binary particles. The significance of this study is that our findings will provide a class of colloidal dispersion state which binary particles were assembled in a high solid content suspension without forming strong aggregates.     

In vivo evaluation of a mucoadhesive polymeric caplet for intravaginal anti-HIV-1 delivery and development of a molecular mechanistic model for thermochemical characterization

Context and objective: The aim of this study was to develop, characterize and evaluate a mucoadhesive caplet resulting from a polymeric blend (polymeric caplet) for intravaginal anti-HIV-1 delivery.

Materials and methods: Poly(lactic-co-glycolic) acid, ethylcellulose, poly(vinylalcohol), polyacrylic acid and modified polyamide 6, 10 polymers were blended and compressed to a caplet-shaped device, with and without two model drugs 3′-azido-3′-deoxythymidine (AZT) and polystyrene sulfonate (PSS). Thermal analysis, infrared spectroscopy and microscopic analysis were carried out on the caplets employing temperature-modulated DSC (TMDSC), Fourier transform infra-red (FTIR) spectrometer and scanning electron microscope, respectively. In vitro and in vivo drug release analyses as well as the histopathological toxicity studies were carried out on the drug-loaded caplets. Furthermore, molecular mechanics (MM) simulations were carried out on the drug-loaded caplets to corroborate the experimental findings.

Results and discussion: There was a big deviation between the T_g of the polymeric caplet from the T_g's of the constituent polymers indicating a strong interaction between constituent polymers. FTIR spectroscopy confirmed the presence of specific ionic and non-ionic interactions within the caplet. A controlled near zero-order drug release was obtained for AZT (20 d) and PSS (28 d). In vivo results, i.e. the drug concentration in plasma ranged between 0.012–0.332?mg/mL and 0.009–0.256?mg/mL for AZT and PSS over 1–28 d.

Conclusion: The obtained results, which were corroborated by MM simulations, attested that the developed system has the potential for effective delivery of anti-HIV-agents.     

Effects of ethylene-octene copolymer (POE) on the brittle to ductile transition of high-density polyethylene/POE blends

Three kinds of ethylene-octene copolymers (POE) were melt-blended with high-density polyethylene (PE-HD) in different proportions. Detailed characterizations were conducted to analyze their structural differences of POE and its effects in toughening PE-HD. The higher molecular weight POE can improve the toughness of PE-HD. 60:40 PE-HD/POE is elongated to break up to 700% while impact strength is 84.7 kJ/m² at −30°C, which is 21-fold of PE-HD. In the brittle to ductile transition (BDT) during impact, the fracture mechanism changes from the crazing mode to the shear yield-plastic deformation mode. The BDT temperature decreases as the POE molecular weight and its content increase. The interface strength in tension is estimated to access their effects. The Boltzmann-type models were successfully extended to describe the typical S-shaped curves in BDT of notched impact strength vs POE content or temperature. The supplementary decay model is suggested for the attenuation in toughening. Transition map in impact is proposed to select the use range of composition (c ) and temperature (T ) for high toughness. The curves are converted into 3D graph of T -c -impact strength for illustrating their coupling-separate effects, and further into the contour map of impact strength in T -c space for finding their partial equivalence.     

从7-ADCA生产过程中环境友好的回收苯乙酸

采用新工艺回收7-氨基-3-脱乙酰氧基头孢烷酸(7-ADCA)生产中产生的苯乙酸,并对苯乙酸回收过程中产生的废硫酸进行处理。采用硫酸(9 8%)洗涤二氯甲烷,硫酸与二氯甲烷适宜的体积比为1∶50,洗涤好的二氯甲烷中含苯乙酸4%。蒸馏出二氯甲烷,趁热向熔融苯乙酸中加入母液,降温析出苯乙酸。晾干的苯乙酸为白色鳞片状,含量大于99%,苯乙酸母液补充部分清水套用到下一批析出苯乙酸。废浓硫酸用芬顿试剂氧化,控制80℃氧化4h,双氧水和七水硫酸亚铁重量比为6∶1,废浓硫酸COD下降85%以上。氧化结束后向废硫酸中加入铁粉和双氧水,制得聚合硫酸铁。     

QS-R02反渗透阻垢分散剂工业应用试验

介绍QS-R02新型反渗透阻垢分散剂在齐鲁股份有限公司橡胶厂反渗透系统的工业试验情况,同QS-R01反渗透阻垢分散剂进行了对比。工业应用试验结果表明:新型QS-R02反渗透阻垢分散剂的碳酸钙临界饱和指数LSI达到2.5,阻垢分散效果明显优于QS-R01,能够实现橡胶厂反渗透系统运行过程不加酸的目的。同时,QS-R02药剂磷含量低,浓水总磷含量达到国家污水综合排放二级标准要求,无环境污染,具有良好的经济效益和社会效益。     

对海水进行混凝除浊预处理研究

介绍采用聚合氯化铁（PFC）为絮凝剂，对海水进行混凝除浊预处理方法。考察了原海水pH、搅拌速度、反应时间及PFC用量对海水预处理效果的影响。结果表明，在原海水pH凋至9．0，搅拌速度控制在200min^-1，反应时间选择8—10min，PFC用量0．10μg／g的最佳条件下，能使处理后的海水浊度降至0．05mol／L，而联产的酸性废水中和剂浆料中Mg（OH）2含量在25％～45％，大肠菌群的去除率大于89．3％。     

含锌离子的聚硅硫酸铝的合成及性能研究

采用一步法制备聚硅硫酸铝絮凝剂合成了含锌离子的聚硅硫酸铝并研究了其性能.含锌离子絮凝剂是一种无毒高效的絮凝剂,且絮凝效果优良,锌离子含量对絮凝剂性能影响很大.