纳米腐植酸基复合树脂的制备及其对Ni~(2+)和Cd~(2+)的吸附

采用水溶液聚合法,以丙烯酸、丙烯酰胺及改性蒙脱土为原料,纳米腐植酸为基体,N,N’-亚甲基双丙烯酰胺为交联剂,过二硫酸钾为引发剂,制备了丙烯酸-蒙脱土-丙烯酰胺/纳米腐植酸复合树脂(简称复合树脂)。考察了溶液pH、吸附时间、吸附温度、初始离子浓度等因素对复合树脂分别吸附Ni~(2+)和Cd~(2+)的影响。实验结果表明:在吸附温度35℃、吸附时间90 min、溶液pH为7、初始Ni~(2+)和Cd~(2+)的浓度分别为0.02 mol/L、复合树脂加入量16.7 g/L的条件下,Ni~(2+)和Cd~(2+)的吸附量分别为383.02 mg/g和359.27 mg/g;复合树脂吸附Ni~(2+)和Cd~(2+)的吸附等温线均满足Langmuir等温吸附方程;吸附过程均符合准二级动力学方程;复合树脂重复使用6次,其对Ni~(2+)和Cd~(2+)的吸附量分别降低了17.1%和9.3%。     

Reaction mode between Si and Fe and evaluation of optimal species in poly-silicic-ferric coagulant

A kind of Fe-polysilicate polymer, poly-silicic-ferric （PSF） coagulant was prepared by co-polymerization （hydroxylation of mixture of Fe^3＋ and fresh polysilicic acid （PS））, in which PSF0.5, PSF1 or PSF3 denotes Si/Fe molar ratio of 0.5, 1 or 3, respectively. The effects of Si/Fe ratio and reaction time （co-polymerization time or aging time） on the reaction mode between Si and Fe were studies, and the optimal species of PSF was evaluated by pH change during the preparation of PSF and coagulation tests. The results showed that the characteristics of PSF are largely affected by both reaction time and Si/Fe ratio. PSF is found to be a essential complex of Si, Fe, and many other ions. The reaction mode between Si and Fe differs with various Si/Fe ratios. The pH of PSF0.5, PSF1 or PSF3 tended to be stable when reaction time is 10, 25 or 55 rain, respectively, which is almost consistent with the time reaching the relative stable morphology that is just the optimal species of higher coagulation efficiency. The optimal reaction time reaching optimal species can be evaluated by measuring the pH change during the polymerization process.     

一种船舶自修复防腐涂料的制备与表征

以脲醛树脂为囊壁、复合环氧树脂为囊芯,采用原位聚合法成功合成了脲醛树脂包覆环氧树脂体系微胶囊。采用扫描电子显微镜观察微胶囊的表面形貌,测量微胶囊的壁厚;利用红外光谱分析判定微胶囊壁材是否形成,芯材是否被完整包覆。结果表明,应用一步原位聚合法可以制备包覆完整、均匀分散、含有特殊芯材的微胶囊。合成的微胶囊形状基本呈球形,粒径分布均匀,平均粒径约为100μm;胶囊表面粗糙致密,粗糙表面主要是由纳米微胶囊沉积而成。微胶囊表面粗糙度的增加有利于增加微胶囊与基体的接触面积,改善微胶囊与基体的界面粘结力,从而提高自修复材料的修复效率。     

Fast and Living Ring-Opening Polymerization of l-Lactide Initiated with In-situ–Generated Calcium Alkoxides

The ring-opening polymerization of l-lactide with calcium alkoxides generated in-situ from bis(tetrahydrofuran)calcium bis[bis(trimethylsilyl)amide] and 2-propanol are presented. The polymerization in THF at room temperature proceeds rapidly and in a living manner, giving poly(l-lactide)s of controlled molecular weight, low polydispersity, and tailored end-functionalities. Kinetic studies show the absence of an induction period and a pseudo-first order rate constant of 6.41 L mol^–1 min^–1, which is significantly higher than for related Y₅(-O)(O ⁱ Pr)_13– or aluminum alkoxide-initiated polymerizations. The initiation involves a two-step process: (1) alcoholysis of bis(tetrahydrofuran)calcium bis[bis(trimethylsilyl)amide] to give the corresponding calcium alkoxide and (2) ring-opening of l-lactide via acyl-oxygen cleavage and insertion into the calcium-alkoxide bond. In the presence of excess alcohol, fast and reversible exchange between free alcohol molecules and coordinated alkoxide ligands takes place. This allows tuning of the poly(l-lactide) molecular weight over a wide range.     

不饱和聚酯树脂生产废水治理技术

不饱和聚酯树脂生产废水CODCr高达 10 0 0 0 0mg/L ,pH为 1— 2 ,且排放无规律 ,处理难度大。采用先对缩聚废水进行蒸馏浓缩 ,再真空泵废水混合调质、降温、缺氧水解后 ,经高效的好氧生物处理工艺 (HCR)处理后与低浓度的冲洗水、生活废水混合 ,进行低负荷的生物接触氧化处理 ,出水CODCr稳定在 10 0mg/L以下。     

Species analysis methods for hydrolysis polymerization of aluminum

ＳｐｅｃｉｅｓａｎａｌｙｓｉｓｍｅｔｈｏｄｓｆｏｒｈｙｄｒｏｌｙｓｉｓｐｏｌｙｍｅｒｉｚａｔｉｏｎｏｆａｌｕｍｉｎｕｍＦｅｎｇＬｉ，ＬｕａｎＺｈａｏｋｕｎ，ＴａｎｇＨｏｎｇｘｉａｏＲｅｓｅａｒｃｈＣｅｎｔｅｒｆｏｒＥｃｏＥｎｖｉｒｏｎｍｅｎｔａ...     

包覆型纳米铁的制备及其去除三氯乙烯的研究

采用微乳聚合法成功的用聚甲基丙烯酸甲脂(PMMA)包覆了纳米铁粒子.透射电镜、红外光谱和热重分析证明,PMMA包覆层存在于铁表面,包覆型纳米铁在空气中的稳定性明显提高.批次实验结果表明,该纳米材料能有效降解环境污染物三氯乙烯(TCE),包覆型纳米铁对TCE的还原反应符合准一级反应动力学.     

反相微乳液聚合PAM在悬浮介质中的絮凝过程研究

研究了Span80-Tween80/异辛烷/H2O反相微乳液聚合丙烯酰胺反相微乳液聚合所得到的PAM的微观结构及其在1%高岭土悬浮液的模拟废水中的絮凝过程与机理。采用电子显微镜、激光纳米粒度仪、分光光度计等测试手段,测定了PAM粒子以及与悬浮介质结合的絮体形态、粒径和粒径分布等微观结构及其絮凝性能。试验结果表明:反相微乳液聚合所制备的PAM为单分散、球形的纳米材料,粒径(D)在145～175nm之间;AMPS改性PAM与高岭土结合后,高岭土与高分子团状结构包埋在一起,透过率较大,絮凝范围宽,可以理解为高分子絮凝剂的"架桥-吸附-网捕"机理。     

两步法制备导电聚吡咯薄膜研究

在陶瓷基底上,先用化学方法,再用电化学方法两步聚合制备导电聚吡咯（PPy）薄膜。研究了施加电流和聚合时间对PPy导电薄膜电导率的影响,对比分析了两步聚合法和化学方法对PPy导电薄膜组织的影响,并对两步法在陶瓷和Al2O3基底上制备PPy导电薄膜的微观形貌进行了观察分析。结果表明,两步聚合方法制备的PPy导电薄膜的电导率随着施加电流的增大和聚合时间的增长而逐渐提高;两步法制备PPy导电薄膜的组织较仅用化学方法制备PPy导电薄膜的组织要致密连续;陶瓷基底上PPy薄膜较均匀,而Al2O3基底上PPy薄膜较疏松且不连续。     

Probe into effect of the initiator on the thermal runaway hazards of methyl methacrylate bulk polymerization

The bulk polymerization of methyl methacrylate (MMA) is of great importance in chemical industry, but the polymerization process is highly hazardous, and few reports have focused on the effect of initiators on its thermal hazards. In this work, to thoroughly explore the thermal hazard characteristics, the runaway behavior of MMA bulk polymerization is investigated by a combination of thermodynamics experimental and kinetics theoretical methods. The results indicate that the presence of initiator exhibits an undesirable thermal hazard to the MMA bulk polymerization, and its exothermic behavior is also greatly influenced by the type and concentration of initiator. For azobisisoheptanenitrile (ABVN), azodiisobutyronitrile (AIBN) and dibenzoyl peroxide (BPO) initiators as examples, the AIBN-initiated reaction has the shortest adiabatic induction period (39.51 min), whereas the BPO-initiated polymerization exhibits the strongest maximum temperature-rising rate and maximum pressure-rising rate. Under adiabatic runaway, the temperature and pressure change significantly with increasing AIBN concentration, revealing a great potential risk of thermal runaway. Kinetic parameters are calculated to further understand the thermal runaway mechanisms, showing a strong agreement with the adiabatic experimental data. Finally, based on the cooling failure scenario, severity grading is determined by the evaluation criteria. The current work provides extensive data as a reference and guidance for the process design and optimization of MMA bulk polymerization from the perspective of safety.