一种简单方法合成聚氨酯/二氧化硅杂化材料及其性能研究

为了获取聚氨酯/二氧化硅(PU/SiO2)杂化材料,采用在聚氨酯主链中引入硅烷偶联剂,然后在碱性且潮湿的条件下加入正硅酸乙酯(TEOS)与硅烷偶联剂缩合形成二氧化硅从而制备出PU/SiO2杂化材料.通过热失重分析(TGA)、动态热机械(DMA)以及万能拉力试验机和接触角测试,详细研究了硅烷偶联剂以及TEOS的用量对PU/SiO2杂化材料性能的影响.结果表明,生成的二氧化硅与聚氨酯形成了较强的化学作用,而不是简单的共混,同时随着生成的二氧化硅的增多,杂化材料的热学性能和力学性能都有大幅的提高,并且膜的表面能也有明显降低.     

水性聚氨酯/纳米二氧化硅杂化材料的研究进展

介绍了制备水性聚氨酯(WPU)/纳米Si O2(二氧化硅)杂化材料的几种方法(如纳米Si O2表面改性法、溶胶-凝胶法和原位聚合法等),特别综述了采用化学接枝改性法制备纳米Si O2和溶胶-凝胶法制备共价键连接的杂化材料的研究进展。最后对WPU/纳米Si O2杂化材料的发展方向提出了建议。     

海藻酸钠改性淀粉的制备及对亚甲基蓝的吸附性能

采用来源广、无毒、可生物降解的海藻酸钠(SA)对玉米淀粉(CSt)进行交联改性,制备海藻酸钠改性淀粉(SA-CSt),并研究了其对溶液中亚甲基蓝的吸附性能。结果表明,在SA加入量为4 g/10 g CSt,交联剂POCl_3加入量为0.09 mL/10 g CSt、反应温度为30℃、反应时间为1.5 h条件下制备的絮凝剂SA-CSt具有最佳的亚甲基蓝吸附性能。当处理50 mL浓度为50 mg/L亚甲基蓝溶液时,在温度为30℃、时间为10 min、絮凝剂SA-CSt加入量为0.075 g时,亚甲基蓝脱色率达97.6%,吸附量达32.53 mg/g。     

羧基化酵母-海藻酸钠复合微球制备及吸附性能

吸附容量小、机械性能差极大地限制了常规海藻酸钠微球的规模化应用。添加改性剂是改善上述缺陷的有效方法。据此,文中利用酵母为增强剂、氯乙酸为改性剂制备了一种新型的具有良好机械性能和高吸附容量的羧基化酵母-海藻酸钠复合微球。扫描电子显微镜表征查明微球呈椭球状,大小均匀。傅里叶红外光谱仪表明,微球表面富含羧基,醚键联接。ZETA电位表明微球的等电点是2.2。以亚甲基蓝为吸附对象,研究了不同质量浓度的亚甲基蓝,pH值对吸附过程的影响。吸附结果表明,随着亚甲基蓝质量浓度的增大,吸附能力也在增大;吸附过程遵循准二阶动力学方程,受颗粒内扩散控制;随着pH值的增大,吸附量显著增大。     

原位交联聚乙烯醇/二氧化硅杂化功能膜的制备与性能

以正硅酸乙酯（TEOS）为前驱体,戊二醛（GA）为交联剂,利用溶胶凝胶法和原位化学交联法相结合的方法,制备了交联的聚乙烯醇/二氧化硅（PVA/SiO2）杂化功能膜。通过FTIR、SEM、溶胀和拉伸实验研究了二氧化硅和原位化学交联对杂化膜结构和性能的影响。结果表明,制备的膜是具有梯度交联结构的有机/无机杂化体系,原位化学交联对膜断面形貌影响不大。二氧化硅的引入和戊二醛原位交联都能有效地降低杂化膜的平衡溶胀度,两种因素在提高杂化膜耐水性方面具有互补作用。     

海藻酸钠微球对铅离子的吸附

以氯化钙为交联剂制备了海藻酸钠微球,对Pb²⁺进行了吸附研究,考察了pH、温度和Pb²⁺起始质量浓度对吸附的影响。结果表明海藻酸钠微球对Pb²⁺有较好的吸附作用,体系pH和Pb²⁺起始质量浓度的提高均有利于微球对Pb²⁺的吸附,吸附过程符合Freundlich模型。在实验条件下,微球对铅离子的吸附为优惠吸附,吸附速率符合准一级动力学方程。     

聚苯乙烯/二氧化硅杂化材料的原位制备

采用活性负离子聚合法和末端官能化改性技术合成三乙氧基封端聚苯乙烯,然后用溶胶-凝胶法合成聚苯乙烯(PS)/SiO2杂化材料,用红外光谱、凝胶渗透色谱、差示扫描量热法、热重分析、扫描电子显微镜对PS/SiO2杂化材料的结构和性能进行分析。结果表明:PS/SiO2杂化材料中的PS和SiO2间有化学键相连;PS/SiO2杂化材料中的w(SiO2)为25%时,SiO2是粒径约为180 nm,且粒径分布均匀、有完善球形结构的颗粒,其玻璃化转变温度比纯PS高1.3℃,热稳定性较纯PS高。     

氯丁二烯-二氧化硅杂化胶乳的制备

纳米二氧化硅的水分散液中直接乳液聚合得到的稳定的氯丁二烯-二氧化硅杂化胶乳。乳胶粒的粒径、ζ电位和透射电镜分析表明纳米二氧化硅吸附在氯丁胶乳粒子的表面。     

SiO2/聚丙烯酰胺类杂化材料的合成研究进展

介绍了SiO2／聚丙烯酰胺类杂化材料的各种制备方法,并对SiO2／聚丙烯酰胺类杂化材料的研究作了展望。     

二氧化硅/聚丙烯酸酯杂化乳胶在外墙涂料中的应用

以二氧化硅为无机组分,甲基丙烯酸甲酯、丙烯酸丁酯、丙烯酸异辛酯为主单体,选择合适的聚合工艺和配方,通过种子乳液半连续法合成二氧化硅/聚丙烯酸酯杂化乳胶,并应用于外墙涂料中,考察其基础性能。通过傅里叶红外光谱仪（FTIR）及透射电子显微镜（TEM）分析表明二氧化硅成功与聚丙烯酸酯复合,形成以二氧化硅为核,聚丙烯酸酯为壳的杂化乳胶。制备的杂化乳胶与纯聚丙烯酸酯乳胶同时应用于外墙涂料中,通过接触角测试（OCA）分析表明：杂化乳胶制备的涂层亲水性更强,水接触角为82°,纯丙配方水接触角为97°;参照外墙涂料标准GB/T 9755—2014,杂化乳胶制备的涂料耐沾污性为7%,相比纯丙乳胶的14%有极大的提升,同时涂料的其他性能,如耐水性、耐碱性、耐洗刷性等均未出现异常劣化。     

SA/FK智能复合微球的交互作用及溶胀性能

采用挤压法制备了海藻酸钠/羽毛蛋白(SA/FK)复合微球。用FTIR和黏度法研究了SA/FK体系的交互作用、探讨了不同制备条件(FK用量、交联剂质量分数、交联时间)、溶胀溶液性质(pH、温度、离子强度)对溶胀性能的影响。结果表明,复合体系的交互作用是静电为主,氢键次之。随着时间延长,溶胀速率变缓,最终达到溶胀平衡。当m(FK)/m(SA)=0.60、w(CaCl2)=7%、交联时间为60 min时,复合微球网络结构最紧密,溶胀速率最低,平衡溶胀率分别为0.6、0.6、0.9。pH由1增加至7,平衡溶胀率仅从0.9升至1.1,当pH=13时,平衡溶胀率升至3.8。温度由30℃提高至45℃,平衡溶胀率从0.6升至0.9。离子强度由0增加至0.6 mol/L,平衡溶胀率从1.1升至13.8。SA/FK复合微球具有pH/温度/离子强度敏感性,有望实现新型智能缓释微球的开发。     

Use of sodium alginate biopolymer as an extracting agent of methylene blue in the polymer-enhanced ultrafiltration technique

In this study, the removal of methylene blue (MB) cationic dye from an aqueous solution was investigated using the polymer-enhanced ultrafiltration (PEUF) technique with sodium alginate (SA) as an extracting soluble polymer, in combination with an ultrafiltration membrane of regenerated cellulose with a 10 kDa molar mass cut-off. SA was characterized via Fourier-transform infrared spectroscopy and thermogravimetric analysis. For ultrafiltration studies, the washing method was used to evaluate various experimental variables, such as the pH, SA dose and initial MB concentration, and adsorption isotherms to identify the optimal adsorption conditions. Finally, the regeneration of the SA polymer was evaluated in five consecutive cycles of adsorption–desorption of MB. In the obtained characterization results, the structural composition of SA and the characteristic thermal stability of the polymer were verified. The PEUF results demonstrated that a retention capacity of 98% of the MB was realized at pH 8.0 using 0.025 g of SA at an initial optimal MB concentration of 50 mg L⁻¹. It is possible to observe that the Freundlich model better explain the interaction between the dye and the polymer surface. According to the results is demonstrated the regeneration capacity of the polymer and its subsequent reuse.     

饲用碘酸钙/海藻酸钠凝胶微球及其稳定性

为隔绝饲用碘酸钙在贮存、使用过程中与还原性物质，如维生素c (VC)的反应。以碘酸钙(Ca(IO3)2)为芯材，海藻酸钠(SA)为壁材，纳米碳酸钙(Nano-CaCO3)为交联钙源，采用改良的内源乳化法制备了碘酸钙/海藻酸钠凝胶微球(Ca(IO3)2/SAMS)。利用FTIR、SEM、TG、XRD对Ca(IO3)2/SAMS进行了表征，同时测定了其在VC溶液中的稳定性，探讨了Ca(IO3)2/SAMS形成机制。结果表明，Ca(IO3)2/SAMS呈球形，粒径约为20~40 μm，其表面有大量碘酸钙晶体。Ca(IO3)2和Ca(IO3)2/SAMS在VC溶液中VC分解50%用时(t50%)分别为54.8 min和78.3 min，Ca(IO3)2在饲料中的稳定性得到明显提升。     

缓释铜的凹土/海藻酸钠复合微球的制备及性能测试

海藻酸钠微球是传统缓控释制剂,提高凝胶强度和增大毛细孔隙率是改善其缓控释性能的有效途径。本文以原子吸收分光光度法辅以微观形貌表征(SEM)和溶胀实验等分析方法,探讨了凹土/海藻酸钠复合微球用于以生命体中微量元素(Cu2+)控释的可行性,并进行了缓释机理分析。实验结果表明,凹土具有显著改善微球的凝胶强度和缓释性能的作用;与海藻酸钠微球相比,复合微球的吸附率由91.82%提高到94.60%,在2 h之内的释放率由66.35%降低到22.78%,表明凹土/海藻酸钠复合微球可作为理想的长效缓释药物的载体。     

Preparation of bovine serum albumin‐imprinted calcium polyacrylate/alginate hybrid microspheres via Ca2+ crosslinking

Macromolecularly imprinted calcium polyacrylate/alginate hybrid polymer microspheres with the imprinting of bovine serum albumin were prepared with sodium alginate and sodium polyacrylate by using CaCl₂ as a gelling agent in inverse‐phase suspension. Infrared spectrum and conductance titration demonstrated that hybrid components were produced in these microspheres. Rebinding isotherms of the microspheres proved a greater bovine serum albumin affinity for imprinted microspheres relative to nonimprinted ones. Selectivity tests indicated that calcium polyacrylate/alginate hybrid polymer microspheres exhibited good recognition properties for the template protein with the separation factor over 5.30 comparing to the competitive proteins with a similar M_w. The influence of cross‐linker CaCl₂ concentration on the imprinting efficiency (IE) and rebinding capacity was researched. It was found that the cross‐linking density and imprinting efficiency of the hybrid hydrogel could be improved simultaneously. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

凹凸棒石用量对海藻酸钠/凹凸棒石复合材料力学性能的影响

以海藻酸钠(SA)为基体,盱眙凹凸棒石(AT)为无机增强材料,采用溶液共混法制备了海藻酸钠/凹凸棒石复合材料。力学性能试验结果表明,当凹凸棒石用量为海藻酸钠质量的2.5%和甘油用量为海藻酸钠质量的3%时,海藻酸钠/凹凸棒石复合材料的力学性能较好。FTIR和SEM测试结果表明,复合材料中海藻酸钠和凹凸棒石之间存在强烈的相互作用和良好的相容性,两者共混明显改善了复合材料的力学性能。     

无机杂化海藻酸钠渗透汽化膜的制备与分离性能对比

为提高海藻酸钠（SA）膜的渗透汽化分离性能,分别采用纳米氧化铝、纳米氧化锆和纳米氧化钛对SA膜进行改性,对比分析了3种不同杂化膜渗透汽化分离性能的差异,并将分离性能较好的杂化膜应用到乙酸与乙醇酯化反应脱水的体系中。系统考察了无机纳米粒子含量对SA膜渗透汽化分离性能的影响,对杂化膜进行了接触角、傅里叶红外（FTIR）、扫描电子显微镜（SEM）、热重/差示扫描量热（TG/DSC）、X射线衍射（XRD）和拉伸强度等表征与分析。结果表明,无机纳米粒子能提高SA膜的热稳定性、机械强度和渗透通量,当无机纳米粒子与SA质量比为0.3时,掺杂TiO₂、ZrO₂和Al₂O₃的杂化膜二碘甲烷的接触角依次升高,同时渗透通量也依次升高。SA-0.3Al₂O₃杂化膜亲水性较好,然而SA-0.3ZrO₂杂化膜分离性能最优,50℃下分离水含量10%的乙醇-水溶液,膜渗透通量达到336 g·m^-2·h^-1,渗透侧水含量99.97%,分离因子29990。酯化反应脱水实验表明,在80℃时,酯化反应脱水实验乙酸转化率均高于无脱水实验乙酸转化率,平衡转化率不断被打破,反应12 h后,转化率由平衡时的79.3%提高到93.9%。     

海藻酸钠/聚乙烯醇溶液的性能及静电纺丝

将质量分数为2%的海藻酸钠(SA)与质量分数为8%的聚乙烯醇(PVA)按一定体积比混合后进 行静电纺丝,研究了SA与PVA溶液的相容性及SA/PVA共混溶液性能.结果表明:SA与PVA溶液相容;随着PVA含量的增加,SA/PVA共混溶液的粘度、表面张力、电导率则降低,共混溶液的可纺性提高;静电纺丝得到的SA/PVA超细...     

Preparation of sodium alginate/poly(vinyl alcohol) blend microspheres for controlled release applications

Sodium alginate (NaAlg)/poly (vinyl alcohol) (PVA) blend microspheres (MS) were prepared by water-in-oil (w/o) emulsion method. These polymer microspheres were crosslinked with glutaraldehyde and loaded with metformin hydrochloride (MHC). The microspheres were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis to confirm the molecular dispersion of the drug, thermal stability, morphological properties, and crystallinity of the polymer matrix before and after blending. SEM of the microspheres suggested the formation of microspheres in spherical structure. Drug release data were analyzed using an empirical equation to understand the nature of drug transport through polymeric matrices. The controlled release (CR) characteristics of the polymer matrices was investigated in pH 7.4 media and from the results it was obtained that the drug was released in controlled manner up to 10 h. The physico-chemical properties of the microspheres were studied by calculating drug entrapment efficiency and drug release kinetics. Percent of encapsulation efficiency (% EE) decreased with increase in crosslinking agent (GA) and PVA content in the microspheres. The optimum % EE (80%) was observed in case of MS containing 40% of PVA with 15% MHC. The release profiles indicate that the release of MHC decreases with increasing the PVA/NaAlg (w/w) and drug/polymer ratio. At the end of 10 h, the highest release of MHC was found to be 96% for MS containing PVA/NaAlg (40 : 60) and 15 wt % drug loaded. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

海藻酸钠的流变性及其纤维性能研究

选用黏均分子量分别为1.59×105和3.27×105的海藻酸钠(A)和海藻酸钠(B),用旋转黏度计研究了两种海藻酸钠溶液的流变性,用热重分析(TGA)、扫描电子显微镜(SEM)研究了海藻纤维的热性能及形态结构。结果表明:海藻酸钠溶液的流变行为具有一般非牛顿流体的基本特征;随剪切速率的增加,溶液黏度下降;温度升高,溶液黏度下降,溶液的非牛顿指数、黏流活化能、结构黏度指数(η)都发生变化;海藻酸钠B的η比海藻酸钠A的较低,可纺性较好;海藻纤维具有良好的热稳定性,其表面具有沟槽结构,较好的吸湿性。