交联法制备聚酰亚胺中空纤维纳滤膜

以不同分子量的聚乙烯亚胺(PEI)和小分子二元胺作为交联剂,对聚酰亚胺(PI)中空纤维膜进行化学交联来制备耐溶剂纳滤膜.考察了PEI分子量和交联时间对膜分离性能的影响.结果表明,膜分离性能随PEI分子量的增加变差,随交联时间的增加变好.用PEI600作为交联剂,交联时间为4h时,膜的纯水通量为8.3L/(m~2·h·MPa),对PEG1000的截留率为97.0%.3种小分子交联剂中,用乙二胺交联膜的分离性能较好,纯水通量为25.8L/(m~2·h·MPa),对PEG1000的截留率为82.6%.纳滤膜对药物三七总皂苷体系有良好的分离性能.     

羟乙基纤维素/聚偏氟乙烯复合膜中支撑膜结构对渗透汽化脱硫性能的影响

用涂布法制成羟乙基纤维素(HEC)/聚偏氟乙烯(PvDF)复合膜;考察PVDF支撑膜铸膜液中聚合物浓度对复合膜结构的影响,并用催化裂化汽油评价复合膜的渗透汽化脱硫性能.结果表明,支撑膜铸膜液聚合物浓度增加将降低支撑膜的孔径、孔隙率,使得汽油组分在支撑膜内的扩散系数和传质系数降低而甲基噻吩和辛烷的传质系数之比增加,导致HEC/PVDF复合膜渗透性降低,富集因子增加.若聚合物浓度过高,支撑膜致密层平均孔径过小,将发生汽油蒸汽局部冷凝,使膜富集因子降低而渗透性增加.     

生物降解型交联PVP材料的制备和性能

合成了一种具有双烯丙基的聚乙二醇和聚乳酸三嵌段共聚物(PLA-b-PEG-b-PLA)的生物可降解交联剂,并以偶氮二异丁氰(AIBN)为引发剂与N-乙烯基吡咯烷酮(NVP)交联制备了一种新型可降解交联膜材料.研究了丙交酯和PEG的投料比对交联剂粘度的影响和交联剂含量和分子量对膜材料的吸水率、接触角和力学强度的影响,初步研究了交联膜材料的降解性能.结果表明:随着丙交酯含量的增加,交联剂的特性粘度增加;随着交联剂含量的增加,膜材料的吸水率减小,接触角增大,拉伸模量增加,断裂伸长率先增加后减小;随着交联剂分子量的增加,膜材料的吸水率和接触角均有增加;对降解性能的研究表明,在降解初期膜材料的质量损失率线性地增加,在降解后期剧烈增加.     

胺交联的磺化聚芳醚砜酮荷电膜的制备及微观结构

采用乙二胺(EDA),己二胺(HDA)和对苯二胺(PPD)为交联剂,与磺化杂萘联苯聚芳醚砜酮(SPPESK)反应生成磺酰胺交联键,制备胺交联的磺化杂萘联苯聚芳醚砜酮荷电膜.通过元素分析确定交联程度.采用示差扫描量热,扫描电镜以及应力-应变测试等方法研究交联膜的微观结构.实验结果表明,交联剂的种类、用量以及SPPESK的初始磺化度显著影响体系的相容性,交联剂用量过高会导致交联膜发生微观相分离,影响交联膜的性能.胺交联法制备荷电膜时交联度不宜过高.     

PDMS/PEI复合膜对FCC汽油的脱硫性能(Ⅰ)制膜条件影响

以聚醚酰亚胺(PEI)超滤膜为支撑层,聚二甲基硅氧烷(PDMS)为复合层,制备PDMS/PEI渗透汽化复合膜对流体催化裂化(FCC)汽油脱硫.通过傅立叶红外光谱仪(FTIR-ATR)对PDMS/PEI复合膜表面进行了结构分析,考察了交联前后官能团的变化.通过扫描电子显微镜(SEM)分析了复合膜表面和断面的形态.将制备的复合膜应用于正庚烷和噻吩体系,研究了不同聚合物PDMS浓度、交联剂浓度,交联温度和交联时间对分离性能的影响,从而得到最佳制膜条件,并考察了膜的溶胀性和在长时间操作下的稳定性.     

核微孔滤膜评价交联聚合物溶液封堵性质的研究

交联聚合物溶液(LPS)是由低浓度部分水解聚丙烯酰胺(HPAM)和交联剂柠檬酸铝(AlCit)形成的．提出了一种新的快速有效地评价交联聚合物溶液的方法，即用核微孔滤膜模拟油藏的微孔介质，以交联聚合物溶液通过核孔波膜的能力——封堵因子评价LPS的形成过程和封堵性能．封堵因子越小，封堵程度越大．实验结果表明，HPAM溶液的封堵因子较大，对孔径为1．2μm核孔膜的封堵程度小，HPAM与交联剂刘AlCit反应形成的LPS对核孔膜的封堵程度随反应时间的增加而增加．因此，该评价方法可以用来评价聚合物与交联剂是否发生交联反应形成LPS．     

PEG/PEI复合膜渗透汽化汽油脱硫研究(Ⅰ)制膜条件影响

以PEI超滤膜为支撑层,PEG为复合层,制备了PEG/PEI渗透汽化RCC汽油脱硫复合膜.通过傅立叶红外光谱仪对PEG/PEI复合膜表面进行了结构分析,考察了交联前后官能团的变化.通过扫描电子显微镜分析了复合膜表面和断面的形态.将制备的复合膜应用于正庚烷和噻吩体系,首先考察了膜的溶胀性和稳定性.研究了不同聚合物PEG浓度、交联剂浓度,交联温度和交联时间对分离性能的影响,从而得到最佳制膜条件.     

多元酸交联聚乙烯醇渗透汽化膜

研究了交联聚乙烯醇(PVA)渗透汽化膜。所用交联剂包括:马来酸酐、草酸、柠檬酸、偏苯三酸酐、邻苯二甲酸酐及1.6己二酸。渗透汽化的结果表明,交联剂的结构对渗透汽化膜的性能有很大的影响。当使用同样当量交联剂时,交联荆的官能度越大,当量越小,膜的分离系数越大而流量越小。交联剂分子中芳香基的存在导致流量增大,分离系数下降。交联膜的热分析结果进一步证实了交联荆结构对选择分离性能的影响。     

多元酸交联聚乙烯醇渗透汽化膜

研究了交联聚乙烯醇(PVA)渗透汽化膜。所用交联剂包括:马来酸酐、草酸、柠檬酸、偏苯三酸酐、邻苯二甲酸酐及1.6己二酸。渗透汽化的结果表明,交联剂的结构对渗透汽化膜的性能有很大的影响。当使用同样当量交联剂时,交联剂的官能度越大,当量越小,膜的分离系数越大而流量越小。交联剂分子中芳香基的存在导致流量增大,分离系数下降。交联膜的热分析结果进一步证实了交联剂结构对选择分离性能的影响。     

壳聚糖膜在重金属处理中的应用研究

以壳聚糖为原料,制备了壳聚糖(CS)超滤膜、邻苯二甲酸二丁酯(DBP-C)壳聚糖多孔膜、壳聚糖/聚乙烯醇(CS/PVA)共混膜三种膜.通过综合运用原子吸收和红外光谱等技术研究交联剂的种类、剂量,对交联壳聚糖膜的物理化学性质与结构的关系及其对重金属离子Cd~(2+)、Pb~(2+)的吸附的影响,添加戊二醛、环氧氯丙烷交联剂对交联壳聚糖微球的影响及其对重金属离子Cd~(2+)、Pb~(2+)的吸附效果.结果表明,交联剂剂量和种类对有效去除重金属离子十分关键,红外光谱研究显示壳聚糖分子中带有的大量活性基团(-NH_2/-OH)与重金属离子配位形成金属螯合物去除了重金属离子;扫描电子显微镜结果表明交联壳聚糖膜在吸附重金属离子前后发生了显著变化,由光滑转变成粗糙.     

Crosslinked sulfonated poly (bis-A)-sulfones as proton exchange membrane for PEM fuel cell application

The crosslinked sulfonated poly (bis-A)-sulfone (SPSF) proton exchange membranes were prepared by immersing the SPSF membrane into the presence of phosphorous pentoxide–methanesulfonic acid (PPMA) in the ratio of 1:10 by weight. The occurring of crosslinking reaction was proved and the membrane properties before and after crosslinking were evaluated. The results showed that the crosslinking treatment has reduced the water uptake, depressed the swelling, and enhanced the dimensional stability of SPSF membranes with just only slight sacrifice in proton conductivity. The ordered arrangement of molecular chain internal SPSF membrane was reduced and the efficiency of crosslinking reaction showed a random property along the depth direction of the membrane in the process of crosslinking.     

UHMWPE纤维的表面交联改性

选用三聚氰酸三丙烯酯(TAC)作为交联剂对超高分子量聚乙烯(UHMWPE)纤维进行紫外辐照交联改性,探讨了正庚烷浸泡时间、交联剂浓度、紫外线辐照时间等因素对UHMWPE纤维表面交联效果及纤维蠕变性能的影响。采用红外光谱、扫描电子显微镜及力学性能测试等多种手段对交联改性前后UHMWPE纤维的结构进行表征。结果表明,UHMWPE在正庚烷中的最佳浸泡时间为24h;紫外线辐照最佳时间为1.5 h;经交联改性后UHMWPE纤维的抗蠕变性能有较明显提高。     

Evaluation of the Film-Coating Properties of a Hydroxyethyl Cellulose/Hydroxypropyl Methylcellulose Polymer System

ABSTRACT

The effect of different grades of hydroxyethyl cellulose (HEC) and hydroxypropyl methylcellulose (HPMC) on the film-formation and taste-masking ability for ibuprofen granules was evaluated. Three batches of coated ibuprofen granules were prepared using a roto-granulator, each with a different coating composition. Two grades of HEC [MW 300,000 (H) and MW 90,000 (L)] were combined with three different grades of HPMC [MW 11,000 (L), MW 25,000 (M) and MW 35,000 (H)] to prepare the coating solutions. Mechanical strength and physical properties of the polymer films were evaluated. Films made from HPMC (L)/HEC (H), HPMC (M)/HEC (H), and HPMC (H)/HEC (H) were stronger and more flexible than the HPMC (L)/HEC (L) films. The assay, dissolution, particle size distribution, and environmental scanning electron microscopy (ESEM) data of the three batches of the coated ibuprofen granules were similar. These data indicated that the two grades of HEC had equivalent film-coating properties. However, the HPMC (L)/HEC (L) film-coated granules showed better taste-masking characteristics (no burning after-taste) than the HPMC (L)/HEC (H) and HPMC (M)/HEC (H) film-coated granules. The ESEM data of the polymer films indicated that both HPMC (L)/HEC (H) and HPMC (M)/HEC (H) films exhibited more roughness and contained larger particles than the HPMC (L)/HEC (L) films. A hydration/dehydration study of the films revealed that HPMC (L)/HEC (H) and HPMC (M)/HEC (H) films were more susceptible to moisture effects, which subsequently led to a faster hydration rate of the polymer films. These data suggest that the molecular weight of the HEC affects the taste-masking ability of the resultant polymer film. The HEC (L) mixed well with the HPMC (L) to yield a uniform film that was more resistant to moisture effects. Hence, for optimum coating applications, particular attention should be paid to the molecular weight of the coating polymers to ensure that they are comparable to each other.     

聚乙烯醇复合膜的制备

以亲水性的聚乙烯醇为原料，采用机械涂敷法制备复合纳滤膜．考查了基膜、聚乙烯醇的浓度、交联剂的浓度及配比、涂层厚度、交联时间以及热处理等对膜分离性能的影响，确定了最终制备条件．在一定的温度和湿度条件下，在截留相对分子质量为100000的基膜上，通过5％的聚乙烯醇溶液与1％的戊二醛的交联反应，研制了截留相对分子质量为600的PVA复合纳滤膜。     

Evaluation of the film-coating properties of a hydroxyethyl cellulose/hydroxypropyl methylcellulose polymer system

The effect of different grades of hydroxyethyl cellulose (HEC) and hydroxypropyl methylcellulose (HPMC) on the film-formation and taste-masking ability for ibuprofen granules was evaluated. Three batches of coated ibuprofen granules were prepared using a roto-granulator, each with a different coating composition. Two grades of HEC [MW 300,000 (H) and MW 90,000 (L)] were combined with three different grades of HPMC [MW 11,000 (L), MW 25,000 (M) and MW 35,000 (H)] to prepare the coating solutions. Mechanical strength and physical properties of the polymer films were evaluated. Films made from HPMC (L)/HEC (H), HPMC (M)/HEC (H), and HPMC (H)/HEC (H) were stronger and more flexible than the HPMC (L)/HEC (L) films. The assay, dissolution, particle size distribution, and environmental scanning electron microscopy (ESEM) data of the three batches of the coated ibuprofen granules were similar. These data indicated that the two grades of HEC had equivalent film-coating properties. However, the HPMC (L)/HEC (L) film-coated granules showed better taste-masking characteristics (no burning after-taste) than the HPMC (L)/HEC (H) and HPMC (M)/HEC (H) film-coated granules. The ESEM data of the polymer films indicated that both HPMC (L)/HEC (H) and HPMC (M)/HEC (H) films exhibited more roughness and contained larger particles than the HPMC (L)/HEC (L) films. A hydration/dehydration study of the films revealed that HPMC (L)/HEC (H) and HPMC (M)/HEC (H) films were more susceptible to moisture effects, which subsequently led to a faster hydration rate of the polymer films. These data suggest that the molecular weight of the HEC affects the taste-masking ability of the resultant polymer film. The HEC (L) mixed well with the HPMC (L) to yield a uniform film that was more resistant to moisture effects. Hence, for optimum coating applications, particular attention should be paid to the molecular weight of the coating polymers to ensure that they are comparable to each other.     

羟化聚天冬氨酸高吸水性树脂的制备及性能研究

以中间体聚琥珀酰亚胺( PSI)为原料,己二胺为交联剂,无水乙醇为分散剂,采用乙醇胺对其进行改性,制备了羟化聚天冬氨酸高吸水性树脂(HPASP).研究了PSI相对分子质量、反应温度、交联剂用量、乙醇胺用量及无水乙醇用量等因素对树脂吸水性能的影响.结果表明,树脂在蒸馏水和0.9％ NaCl水溶液中的吸水率分别达到804g...     

Triethylenetetramine/hydroxyethyl cellulose-functionalized graphene oxide monoliths for the removal of copper and arsenate ions

Nitrogen-doped graphene oxide monoliths (GOMs) were readily constructed by crosslinking graphene oxide (GO) using triethylenetetramine (TETA) and hydroxyethyl cellulose (HEC). The addition of HEC was beneficial to the formation of a network structure compared to that in the absence of HEC. The generated monoliths have shown various morphologies with different d spacing, layer thickness, and micropore size. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses provided evidences for the formation of covalent C–N bonds and some nitrogen-containing heterocyclic composition inside the graphene oxide sheet, indicating that the interaction of GO with the amine crosslinker involved the crosslinking reaction between GO epoxides and amine groups. HEC was also involved in the N-doping reaction via the partial reduction of oxygen in HEC molecules. Analysis of X-ray diffraction (XRD) results indicated that the lattice distance between GO sheets increased after TETA/HEC crosslinking. Thermogravimetric analysis (TGA) confirmed the successful incorporation of crosslinker moieties on the surface of GO sheets. The fabricated GOMs could be used to efficiently adsorb metal ions and arsenate by the introduced polar functional groups on GO sheets and porous structures based on hydrogen bonds, whose morphologies and compositions were confirmed via XRD, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS).     

紫外光辐照交联对超高相对分子质量聚乙烯纤维结构和性能的影响

在光敏剂和交联剂存在下，用紫外光进行辐照引发对超高相对分子质量聚乙烯（UHMWPE）纤维进行交联改性。从纤维凝胶含量、力学性能、耐热性、蠕变性、粘结性能、结外光谱及扫描电镜（SEM）等测试分析得知，UHMWPE纤维的性能和结构发生了重要变化，其耐热性和抗蠕变性能有了明显的提高，纤维的表面粘结性能得到了改善，同时，UHMWPE纤维保持了原丝的优异的力学性能。