8-羟基喹啉改性DK110树脂的合成及其对Cu~(2+)的吸附性能

以大孔丙烯酸系弱酸树脂DK110为大分子骨架,通过与5-氯甲基-8-羟基喹啉的接枝反应,合成了带8-羟基喹啉螯合功能基的改性树脂HQDK110。探讨了HQDK110树脂对Cu2+在不同温度、不同pH值、不同浓度等条件下的静态吸附性能、动态吸附性能及脱附性能。结果表明,HQDK110树脂对Cu2+具有良好的吸附作用,实验条件下,25℃时HQDK110树脂对Cu2+的吸附量达2.278 mmol/g。HQDK110树脂对Cu2+的动力学吸附很好地符合了拟二级动力学模型,吸附过程符合Langmuir吸附等温式。树脂对Cu2+的去除率在较宽的浓度范围内达到98%以上,吸附Cu2+后的树脂在0.1 mol/L的盐酸溶液中的脱附率达96.88%。树脂有良好的重复使用性能。     

水杨羟肟酸功能化聚合物/硅胶螯合吸附材料SHA-PHEMA/SiO_2的制备及吸附性能

首先采用氯甲基化试剂1,4-二氯甲氧基丁烷对水杨羟肟酸(SHA)实施氯甲基化反应,制得氯甲基化水杨羟肟酸(CMSHA);然后以聚甲基丙烯酸羟乙酯(PHEMA)改性的硅胶微粒PHEMA/SiO2为载体,使其表面的醇羟基与CMSHA上的氯甲基基团发生亲核取代反应,制得水杨羟肟酸功能化的复合螯合吸附材料(SHA-PHEMA/SiO2)。考察了取代反应的主要影响因素;并研究了SHA-PHEMA/SiO2对重金属离子的螯合性能。结果表明,CMSHA与PHEMA/SiO2之间的取代反应遵循单分子取代反应(SNl)的机理;较高温度下,强极性溶剂有利于反应的进行。SHA-PHEMA/SiO2对不同重金属离子表现出不同的螯合吸附能力,摩尔吸附容量的顺序为Cu2+Zn2+Cd2+Pb2+;SHA-PHEMA/SiO2对Cu2+离子的吸附动力学符合伪二级速率方程;其吸附行为同时遵循Freundlich和Langmuir模式。     

氨基功能化大尺寸SiO2大孔材料的制备及其吸附性能

以具有三维骨架结构的环氧树脂大孔聚合物为整体型模板,利用硅酸酯原位水解和高温烧结制备出大尺寸SiO2大孔材料。在溶剂热条件下,用3-氨丙基三乙氧基硅烷对SiO2大孔材料进行表面修饰,得到氨基功能化SiO2大孔材料(H2N-SiO2)。用SEM和FT-IR对制备的大孔材料进行了表征。以Cu2+和Pb2+为模拟污染物,研究了H2N-SiO2的吸附性能。结果表明,室温下,在pH值为6.5时能有效吸附Cu2+和Pb2+;吸附为放热自发过程;吸附过程符合准二级动力学方程;吸附等温线用Freundlich方程拟合的结果优于Langmuir方程,H2N-SiO2对Cu2+和Pb2+的理论最大吸附量分别为76.0和143mg/g;H2N-SiO2对50mg/L水溶液中Pb2+的去除率可达99.4%,重复使用3次后对Pb2+的去除率保持在87.8%。     

弱酸型酚醛树脂对重金属离子的吸附

研究了以苯酚、氯乙酸及甲醛等为原料合成的弱酸型酚醛树脂对重金属离子Ni2+,Cu2+,Zn2+,Pb2+的吸附性能,考察了吸附时间、吸附温度、溶液浓度及pH值对该树脂吸附性能的影响。结果表明,在温度为25℃、pH值为4.5的条件下,该树脂对Ni2+,Cu2+,Zn2+,Pb2+的吸附容量可达到2.4×10-3mol/g,去除率均可达到97.5%以上。吸附了重金属离子的树脂可用5%的盐酸再生并回收重金属离子。     

聚乙烯亚胺-羧甲基纤维素的合成及对金属离子的吸附性能

以羧甲基纤维素(CMC)为基质,用戊二醛(GA)做交联剂,将聚乙烯亚胺(PEI)交联到羧甲基纤维素上制得聚乙烯亚胺-羧甲基纤维素吸附剂(PEI-CMC)。采用傅里叶变换红外光谱、扫描电镜、X射线光电子能谱对PEI-CMC的结构进行了表征,测定了其对Cu2+、Pb2+和Cd2+的吸附性能,并研究了pH值、时间、金属离子的初始浓度对吸附的影响。结果表明,当CMC、PEI和GA的反应比为1 g∶5 mL∶20 mL,反应温度为25℃,反应时间为3 h时,合成的PEI-CMC的含氮量为13.23%。当CMC和PEI的反应比为1 g∶5 mL时,随着戊二醛(质量分数2.5%)的加入量增加,PEI-CMC的产率先增大后降低。在pH值1~14的范围内,溶液酸碱度的变化对PEI-CMC的交联度没有影响。PEI-CMC吸附剂对Cu2+、Pb2+和Cd2+的吸附量在实验范围内随pH升高而增加。PEI-CMC对Pb2+和Cu2+、Cd2+的吸附在90 min和180 min后分别达到平衡,吸附动力学符合准二级反应动力学模型。随着Cu2+、Pb2+和Cd2+初始浓度的增加,PEI-CMC对Cu2+、Pb2+和Cd2+的吸附量开始时快速增加,而后达到饱和,吸附等温数据符合Freundlich模型,最大吸附容量分别为Cu2+250.0mg/g、Pb2+635.9 mg/g、Cd2+142.8 mg/g。     

改性没食子酸对Cu~(2+)和Pb~(2+)吸附沉淀性能的研究

以含单宁量98.50%的没食子酸为原料,通过磺化一胺甲基化反应制得改性没食子酸,研究了改性没食子酸对金属Cu2+和Pb2+的吸附沉淀,以及初始溶液pH值、金属溶液初始质量浓度、平衡吸附温度对Cu2+和pb2+吸附沉淀容量的影响及规律.结果表明,吸附沉淀剂对Cu2+、Pb2+的吸附平衡符合Freundlich方程,pH值和初始质量浓度对吸附沉淀量的影响最显著.综合认为改性没食子酸对Cu2+、Pb2+的吸附沉淀机理基本一致.     

硫代乙酰胺键合硅胶吸附剂的制备及对铜铅的吸附性能

制备了硫代乙酰胺键合硅胶(TAA-SG),并以它作为固相萃取吸附剂,通过火焰原子吸收光谱法(FAAS)研究了对Cu2+、Pb2+的萃取性能。系统考察了pH、振荡时间和吸附容量等静态吸附性能实验以及流速、洗脱液条件、最大试样体积和干扰离子等动态吸附性能实验对Cu2+、Pb2+定量回收的影响,确定了最佳吸附条件。实验结果表明,当介质的pH为5时,振荡25 min时吸附达到平衡,对Cu2+、Pb2+的最大吸附容量分别为15.05 mg/g和21.10 mg/g。TAA-SG用于饮用水中痕量Cu2+、Pb2+的吸附富集测定,加标回收率在98.4%~102.0%之间。     

改性海泡石对电镀废水中Pb2+、Cu2+、Cd2+的吸附

用盐酸溶液对海泡石处理后在 4 5 0℃下灼烧 ,制备出改性海泡石。在动态条件下 ,研究了改性海泡石对重金属离子Pb2 +、Cu2 +、Cd2 +的吸附效果及条件。探讨了改性海泡石对重金属离子Pb2 +、Cu2 +、Cd2 +的吸附机理。含Pb2 +、Cu2 +、Cd2 +的电镀废水经改性海泡石吸附后 ,重金属离子含量显著低于国家排放标准     

两性细菌纤维素对持久性污染物的吸附机理研究

以细菌纤维素为原料,分别以烯丙基胺和丙烯酸为单体,以硝酸铈铵为引发剂制备新型、高效的两性吸附材料——烯丙基胺-丙烯酸-细菌纤维素(al-AABC)。通过静态吸附实验,考察了其对持久性污染物Cu2+、Pb2+、Cd2+和Cr(Ⅵ)的吸附等温线和吸附动力学特性,并探讨了吸附作用机理。结果表明,al-AABC对Cu2+、Pb2+、Cd2+和Cr(Ⅵ)吸附更好地符合Langmuir-Freundlich吸附等温方程和准二级反应动力学模型,说明BC经接枝共聚改性后表面具有一定的多相性,以化学吸附作用为主,对金属离子的吸附速率大小顺序为Cd2+Cr(Ⅵ)Pb2+Cu2+。粒子内扩散拟合曲线均不经过原点,证明粒子内扩散并不是唯一速率控制步骤。     

多氨基改性蔗渣对水溶液中Pb~(2+)、Zn~(2+)、Cd~(2+)、Cu~(2+)吸附性能的研究

蔗渣经多氨基改性处理后,得到多氨基改性蔗渣吸附剂。考察了多氨基改性蔗渣吸附剂对模拟废水中Pb2+、Zn2+、Cd2+、Cu2+的吸附性能,主要包括吸附时间、溶液pH值和温度对吸附量的影响以及吸附等温式的研究。研究表明,在实验范围内,Pb2+的吸附平衡时间为12h,适宜吸附Pb2+的pH值范围在4～5,Pb2+的最大吸附量为34.96mg/g;Zn2+的吸附平衡时间为20h,适宜吸附Zn2+的pH值在6.2左右,Zn2+的最大吸附容量为2.24mg/g;Cd2+的吸附平衡时间为20h,适宜吸附Cd2+的pH值在5.0左右,Cd2+的最大吸附容量为10.40mg/g;Cu2+的吸附平衡时间为20h;适宜吸附Cu2+的pH值在5.0左右;Cu2+在不同温度下的最大吸附容量为2.60mg/g。多氨基改性蔗渣对Pb2+、Zn2+、Cd2+、Cu2+的吸附均可用Freundlich方程和Langmuir方程描述。     

氰酸酯／双马来酰亚胺／环氧树脂三元共聚物及性能研究

采用双马来酰亚胺和环氧树脂与氰酸酯共聚对氰酸酯树脂进行改性，用FTIR跟踪了其固化过程。性能测试表明，当BCE：BMI：EP为5：2：3时，其固化物的冲击强度达到了12．2kJ·cm^-2，韧性有较大的提高；改性树脂的耐热性随着EP含量的增加而下降，当EP含量为30％时，Tg为233．7℃；改性后的氰酸酯树脂在1MHz频率下的介电常数和介电损耗角正切都比纯CE的有所增加，但上涨的幅度较小，仍具有优异的介电性能；DMA分析表明，在瓦温度时，损耗因子和损耗模量达到最大值，其中，tanδmax为0．359。     

环氧改性酚醛树脂的耐腐蚀性能研究

利用环氧树脂(PF)与酚醛树脂(EP)共混,再冷压-烧结成型得到改性酚醛树脂.通过在70%、50%、30%硫酸、50%盐酸、20%氢氧化钠溶液中改性酚醛树脂的腐蚀实验,证明环氧改性酚醛树脂的耐腐蚀性能优于纯酚醛,其中耐腐蚀性能最好配方是PF:EP=100:50.改性酚醛树脂耐酸性能优于耐碱性能,且在非氧化酸性(盐酸)环境中的耐腐蚀性能优于氧化性酸性(硫酸)环境下的耐腐蚀性能.热重分析(TGA)表明,环氧改性酚醛树脂的耐热性能较纯酚醛有所提高.     

Internal stress of epoxide resin modified with spiro ortho-ester type resin

The internal stress and shrinkage of bisphenol type epoxide resin compounded with spiro ortho-ester resin were investigated by measuring the change of density and the strain of the steel ring embedded in the cured resins. Internal stress was absent in the rubbery region and was mainly induced by shrinkage in the glassy region. The shrinkage in the glassy region seems to be directly converted to internal stress because the motion of network segments is restricted in this region. The internal stress decreased with increasing fraction of spiro ortho-ester resin in the cured system. The reduction of internal stress was independent of the expansion of the cured resin caused by the reaction of spiro rings during the curing process. This reduction was due to the decrease in the glass transition temperatureT _g of the cured resins, that is the decrease in the shrinkage occurring in the cooling process fromT _g to room temperature.     

Internal stress of epoxide resin modified with spiro ortho-ester type resin

Bisphenol-A type epoxide resin modified with various amounts of spiro ortho-ester (SOE) resin was cured with an imidazole. Internal stress of the modified systems decreased with increasing fraction of SOE resin in the cured resins. In particular, a drastic reduction of the internal stress was observed in the systems modified with more than 33 mol% SOE resin. In addition, heterogeneous structure was observed with modifier content over 33 mol%, and the elastic modulus of these systems decreased step-wise with increasing ambient temperature. On the other hand, the systems in which the modifier content was less than 20 mol% had homogeneous structure and thus the modulus was considerably higher than that of the former systems. Consequently, it was concluded that the drastic reduction of the internal stress in the systems modified with more than 33 mol% SOE resin depends on the low elastic modulus caused by the formation of heterogeneous structure.     

Methods for process-related resin selection and optimisation in high-pressure resin transfer moulding

ABSTRACT

A framework for process-related resin selection and optimisation is proposed in the context of research and development for industrial applications of high-pressure resin transfer moulding. The first stage involves validation of the reaction kinetics model by differential scanning calorimetry and characterisation of viscosity, storage- and viscous-shear moduli by dynamic mechanical analysis in a rheometer as a function of time. It also includes capillary pressure measurements of curing resin impregnating a fibre yarn. Process-related resin selection criteria are based on the optimisation of cycle time, including filling time against gel time, micro-infiltration time and demould time. The proposed framework and associated test and analysis methodologies are applied to three epoxy resin systems in connection with carbon fibre reinforcement.     

真空辅助成型(VARI)用低黏度环氧树脂研究进展

综述了以环氧树脂为主的国内外真空辅助成型技术(VARI)用低黏度树脂基体的研发现状,以及双酚F及改性双酚F环氧树脂研究现状,分析了双酚F及改性双酚F环氧树脂应用于真空辅助成型技术(VARI)的潜力.     

Influence of novel additive on BMI resin and BMI resin matrix composite

In order to achieve high performance BMI matrix composite manufactured by vacuum bag cure only technique, a novel additive WD-01 was selected to modify BMI-B resin based on modified polyetherketone (PEK-C) toughened 4,4′-bismaleimidodiphenyl methane (MBMI)/O,O′-diallybisphenol A (DABPA) system, and the properties of WD-01 modified BMI resin (BMI-WD) and resin matrix composite were investigated here. Results indicated that the cure shrinkage rate of BMI-B resin was reduced from original 4.0% to 1.8% and the surface morphology of neat resin casting were changed significantly by incorporating 1 wt.% WD-01, no change of chemical cure behavior of BMI resin was observed. Vacuum consolidated BMI-WD/T700 laminates had autoclave cure quality with excellent mechanical properties. A high performance of vacuum-bag curable prepreg with promising characteristics is being developed and expected to find use in advanced composite structures.     

Chemorheology of epoxy resin

A secondary hydroxyl group containing epoxy resin was reacted and cross-linked with polyurethane (PU). This PU-cross-linked epoxy resin was cured with a tertiary amine and the viscosity and dynamic mechanical properties were determined by a cone-and-plate rheometer. A dual Arrhenius viscosity model was modified to predict the viscosity profile with time before gelation during non-isothermal curing, and the calculated values coincided with the experimental data. The activation energy of this system (NCO/OH ratio=30 mol%) calculated by the modified model was 13kcal mol^–1 for the initial region, and 16.8 kcal mol^–1 for the final region. After gelation, the dynamic complex modulus was correlated to the reaction kinetics according to the rubber elasticity theory, and the activation energy calculated was 5.2 kcal mol^–1. These activation energies are all lower than those of the unmodified epoxy resin system. Consequently, the reaction rate of the PU-cross-linked epoxide system was less affected by temperature than that of the unmodified epoxide system. It was also found that the rate of increase of viscosity and dynamic moduli decreased with increasing PU content. The gelling point was estimated by rheological measurements.