Tuning of shear thickening behavior and elastic strength of polyvinylidene fluoride via doping of ZnO-graphene

ZnO rice like nonarchitects are grafted on the graphene carbon core via a rapid microwave synthesis route. The prepared grafted systems are characterized via XRD, SEM, RAMAN, and XPS to examined the structural and morphological parameters. Zinc oxide grafted graphene sheets (ZnO-G) are further doped in β-phase of polyvinylidene fluoride (PVDF) to prepare the polymer nanocomposites (PNCs) via mixed solvent approach (THF/DMF). β-phase confirmation of PVDF PNCs is done by FTIR studies. It is observed that ZnO-G filler enhances the β-phase content in the PNCs. Non-doped PVDF and PNCs are further studied for rheological behavior under the shear rate of 1–100 s⁻¹. Doping of ZnO-G dopant to the PVDF matrix changes its discontinuous shear thickening (DST) behavior to continues shear thickening behavior (CST). Hydrocluster formation and their interaction with the dopant could be the reason for this striking DST to CST behavioral change. Strain amplitude sweep (10⁻³% -10%) oscillatory test reveals that the PNCs shows extended linear viscoelastic region with high elastic modulus and lower viscous modulus. Effective shear thickening behavior and strong elastic strength of these PNCs present their candidature for various fields including mechanical and soft body armor applications.     

聚苯乙烯溴代并接技聚二甲基硅氧烷

聚苯乙烯（PS）在苯溶液中与溴代丁二酰亚胺（NBS）反应，经分离提纯得到了固体溴代聚苯乙烯（PSB）。将所得PSB溶于苯并与低分子量的聚二甲基硅氧烷硅醇锂（PDMSOLi）反应，经分离提纯得到固体的溴代聚苯乙烯接枝聚二甲基硅氧烷（PSB－g-PDMSO),所得PSB-g-PDMSO的结构经^1H-NMR、IR及TEM表征。     

Dual reaction capacity of hydrogenated nanodiamond

High temperature hydrogen stream treatment of nanodiamond was shown to produce nanodiamond with bifunctional surface. OH- and different CH-groups were shown to be the main functional groups on the surface. In this article we proposed two main strategies for further chemical modification of hydrogenated nanodiamond. OH-groups were shown to react with different types of acylating agents: anhydrides and chloranhydrides. Chlorination of hydrogenated nanodiamond with molecular chlorine and its subsequent treatment with alkyllithium reagents resulted in formation of alkyl-nanodiamonds. Chlorination was shown to reduce the size of nanodiamonds aggregates. We have also applied suspension-state NMR-H1 spectroscopy to study suspensions of alkyl-nanodiamonds for the first time.     

Radiation-induced modification of polyurethane with hydroxyethyl methacrylate: blood compatibility

An attempt is made to develop the hydrophilic grafting of polyether urethane urea with hydroxyethyl methacrylate (hema) using⁶⁰Coγ-irradiation for achieving optimum hydrophilic/hydrophobic property needed towards blood compatibility. Contact angle method and platelet adhesion from calf’s blood are used to determine the suitability of these modified surfaces.     

2-羟丙基三甲基氯化铵壳聚糖的制备及其表征

以脱乙酰度为90%的壳聚糖(CTS)为原料,异丙醇为溶剂,w(NaOH)=40 0%的水溶液为催化剂,3 氯 2 羟丙基三甲基氯化铵(CTA)为改性剂,在m(NaOH)∶m(CTS)=1 0∶1 0,m(CTA)∶m(CTS)=4 0∶1 0,反应温度65 0℃下制备了2 羟丙基三甲基氯化铵壳聚糖(HTCC)。实验结果表明,在反应时间达到或超过9 0h时,得到的HTCC产品的接枝度超过90 0%,在pH=6 7～7 0的水中可完全溶解形成w(HTCC)=3 0%的溶液。IR和1HNMR的结果表明,接枝反应主要发生在CTS的氨基上。     

界面改性剂对PP/滑石粉形态结构和性能影响

用在50L固相接枝反应器中合成的等规聚丙烯接枝马来酸酐(PP-g—MAH)作界面改性剂，制备了PP—g—MAH／PP／滑石粉复合材料。研究了PP—g—MAH／PP／滑石粉复合材料的形态结构和力学性能。结果表明，PP—g—MAH对PP／滑石粉复合物的缺口冲击强度、弯曲强度和拉伸强度均有增强作用；PP—g—MAH对PP／滑石粉复合物表观粘度几乎没有影响。SEM观察发现PP—g—MAH对PP／滑石粉复合物相界面有明显的改善。     

聚丙烯的官能化及其与尼龙66相容性研究

对聚丙烯（PP）进行官能化，并研究了接枝单体含量，引发剂含量，螺杆转速对接枝率和熔体流动速率的影响。再将不同接枝率的PP与尼龙66共混，研究了接枝率对共混物力学性能及相容性的影响；用扫描电子显微镜观察了共混物的形态，与未增容共混体系相比，增容后共混体系分散相尺寸明显减小，增容共混物的形态依赖于增容剂在共混物中的含量，增容剂的分子量及官能化基团的含量。     

HDPE-AA-SSS预辐照接枝膜的表征及其湿敏性能的研究

采用预辐照法将亲水性单体丙烯酸(AA)和对苯乙烯磺酸钠(SSS)接枝到疏水性高密度聚乙烯(HDPE)薄膜上,制备出新型的接枝膜湿敏元件.通过扫描电镜观测了辐照接枝前和接枝后HDPE膜的表面形貌,并通过红外光谱表征了膜的结构,同时测定了接枝膜湿敏元件的湿敏性能.实验结果表明,制备的接枝膜湿敏元件具有良好的湿敏特性,响应和恢复时间短.它具有较好的稳定性,能在高湿、高温环境下使用.实验结果也表明了接枝HDPE膜具有良好的湿敏性能.     

聚氨酯改性氯丁接枝低毒溶剂型鞋用胶粘剂的研制

研究了一种能粘多种材质的溶剂型鞋用大底胶。该胶为一种聚氨酯改性氯丁、SBS接枝胶,粘接范围广,对PU、TPR、SBS等材质粘接性能比氯丁接枝胶好,适合鞋厂流水生产线;所用溶剂毒性相当低,对人无害,有利于劳动保护和环境保护。     

mPE-g-MAH对HDPE/木粉复合材料的改性

采用废木粉填充高密度聚乙烯（HDPE）制备木塑复合材料。采用马来酸酐接枝茂金属聚乙烯（mPE—g-MAH）对复合材料进行增容和增韧，并阐述了它的增容和增韧机理。讨论了mPE—g—MAH用量对复合材料的力学性能如拉伸强度、冲击强度、弯曲强度、弯曲模量的影响。结果表明，mPE—g—MAH不仅可明显提高复合材料的强度和韧性，而且也使材料的弯曲模量有了一定的提高。当其质量分数为16％时，复合材料的拉伸强度、冲击强度分别由原来的16．2MPa和4．5kJ／m^2提高到30．5MPa和9．8kJ／m^2。