N-异丙基丙烯酰胺pH敏感型水凝胶的制备及对甲基紫吸附性能研究

以N-异丙基丙烯酰胺和海藻酸钠(SA)为主要原料,制备了具有pH敏感型的智能水凝胶。探究了不同海藻酸钠、引发剂、交联剂等配比的凝胶在不同pH值环境下的溶胀性能,并对制备的凝胶进行甲基紫的吸附性能测试。结果表明:碱性条件下,凝胶溶胀度随SA用量的增加而增大,酸性条件下则相反;凝胶的溶胀度随交联剂用量的增加而减小;引发剂用量为3%时凝胶的溶胀度较高;凝胶在适宜条件下对甲基紫溶液有良好的吸附性能。     

明胶对明胶/壳聚糖共混膜性能影响的研究

采用溶液共混法制备出了一系列明胶／壳聚糖共混膜,并考察了制备条件对膜性能的影响。结果表明：明胶的溶解方式对吸水率和溶胀比影响很小;随明胶分子量增加,共混膜的吸水率和孔洞体积增大;而随共混体系中明胶质量分数的增加,吸水率和孔洞体积亦增加,但溶胀比下降。     

羧基丁腈橡胶/明胶共混物的制备及其亲水性和吸湿性

采用羧基丁腈胶乳与明胶溶液共混制备了羧基丁腈橡胶(XNBR)/明胶共混物,对其结构进行了表征,考察了明胶加入量对共混物亲水性和吸湿性的影响.结果表明,XNBR的羧基与明胶的氨基之间发生了反应.明胶的加入使共混物的亲水性和吸湿性得到明显改善,且随明胶加入量的增大,共混物的亲水性和吸湿性提高;模拟生理溶液体系的pH值对共混...     

阳离子羟乙基纤维素溶液黏度性能的研究

以羟乙基纤维素（HEC）为原料,2-氯-4,6-二（N,N-二甲基-N-苄基1,3-丙二胺）1,3,5-均三嗪为改性剂,制备出不同取代度阳离子羟乙基纤维素。同时探讨了取代度及其浓度、阳离子及其浓度、转子转速、温度、pH值对阳离子羟乙基纤维素（CHEC）的黏性行为的影响。结果表明,阳离子羟乙基纤维素溶液黏度随着CHEC浓度增大、温度的升高、pH值的增加而减小。同一CHEC质量浓度下,取代度越高,转子的转速降低,黏度增大。CHEC在K₂SO₄溶液中的黏度总低于MgSO₄溶液中黏度;随着阳离子浓度的增加,CHEC溶液的黏度降低。     

HEC与SA复合海绵的制备及性能表征

制备不同比例的羟乙基纤维素/海藻酸钠复合海绵,根据医用敷料海绵的国家标准要求,对其进行表面密度、吸水、保湿、孔隙率等测试,并利用红外光谱仪测试其复合前后的结构变化以及利用万能试验机及热重分析仪测试复合海绵的力学性能及热稳定性等特征。结果表明：羟乙基纤维素与海藻酸钠溶液可以以一定比例共混并冷冻干燥制备成复合海绵,两者之间只是物理共混,没有发生化学变化,其相容性良好,无明显相分离现象出现;共混比例对混合海绵的物理性能产生一定的影响。综合考虑各项性能参数,羟乙基纤维素与海藻酸钠两种组分的比例为3：1时,此时所制备形成的海绵为最佳。     

羟乙基纤维素/甲基咪唑硫酸氢盐共混质子交换膜的制备与表征

质子交换膜是氢燃料电池的重要组成部分之一。本文将甲基咪唑硫酸氢盐质子化离子液体与羟乙基纤维素共混,通过溶液浇铸法制备了均匀透明的质子交换膜。交流阻抗测试表明,共混膜的传导率随着离子液体比例的增加而增大,70%(wt)时传导率达到2.9×10~(-3) s/cm。质子传导率随使用温度的变化基本服从Arrhenius定律,表明质子主要通过跳跃机理实现传导,传导活化能随着离子液体比例的增加而降低。     

IIR/CIIR共混胶的动态力学性能

研究了共混比、硫化体系、增强剂、软化剂和硅烷偶联剂对IIR/CIIR共混胶动态力学性能的影响。结果表明,随CIIR用量增加,共混胶的储能模量(E')和损耗模量(E″)逐渐增加,而阻尼因子(tanδ)峰值逐渐减小,共混胶的玻璃化转变温度(Tg)向高温方向偏移;采用叔丁基酚醛树脂硫化的共混胶的E″比硫黄硫化的高,但tanδ峰值和Tg均低于后者;细粒子高结构炭黑N220填充的共混胶的E'和E″较高,tanδ峰值较低,而粗粒子半增强炭黑N754填充的共混胶的E'和E″较低,tanδ峰值较高;软化剂凡士林的加入,使共混胶的E'和E″降低,tanδ峰值增加,而且Tg向低温方向偏移;γ-氨基丙基三乙氧基硅烷增加了共混胶的E'和E″值,但tanδ峰值降低,Tg基本不变。     

海藻酸钠/明胶混合水溶液的流变性能

借助旋转黏度计考察了海藻酸钠/明胶混合水溶液的流变性能,发现混合溶液具有剪切变稀的非牛顿假塑性流体特征;随体系中明胶含量的增加,相应混合溶液的稠度系数增大而黏性指数下降,同时溶液的触变性能得以增强,该混合溶液体系具有协同增效性。     

ⅡR/CⅡR共混胶的动态力学性能

研究了共混比、硫化体系、增强剂、软化剂和硅烷偶联剂对ⅡR/CⅡR共混胶动态力学性能的影响。结果表明,随CⅡR用量增加,共混胶的储能模量(E′)和损耗模量(E″)逐渐增加,而阻尼因子(tanδ)峰值逐渐减小,共混胶的玻璃化转变温度(Tg)向高温方向偏移;采用叔丁基酚醛树脂硫化的共混胶的E″比硫黄硫化的高,但tanδ峰值和Tg均低于后者;细粒子高结构炭黑N220填充的共混胶的E′和E”较高,tanδ峰值较低,而粗粒子半增强炭黑N754填充的共混胶的E′和E″较低,tanδ峰值较高;软化剂凡士林的加入,使共混胶的E′和矿降低,tanδ峰值增加,而且乃向低温方向偏移;γ—氨基丙基三乙氧基硅烷增加了共混胶的E′和E″值,但tanδ峰值降低,Tg基本不变。     

纤维素/海藻酸钠共混膜的制备及力学性能

将纤维素和海藻酸钠分别溶于氢氧化钠/尿素/硫脲体系,制得纤维素膜和纤维素/海藻酸钠共混膜,通过正交实验和单因素实验法分析,确定制备纤维素膜的最佳工艺条件,在此基础上研究了纤维素/海藻酸钠共混膜的制备工艺。结果表明:质量分数为4.5%的纤维素溶液所制得的膜在25℃的5%的硫酸溶液中凝固15 min,20%的甘油溶液中塑化30 min,其膜的拉伸强度较佳为5.2 MPa;纤维素/海藻酸钠共混膜的较佳工艺:质量分数分别为4.5%的纤维素溶液和3%的海藻酸钠溶液按质量比100/5共混后先浸入5%硫酸溶液中反应15 min,再放入10%氯化钙溶液中凝固10 min,用15%甘油溶液塑化15 min后,共混膜的拉伸强度达到3.50 MPa。     

Blend films from konjac glucomannan and sodium alginate solutions and their preservative effect

In order to enhance the mechanical properties of konjac glucomannan film in the dry state and research the application of konjac glucomannan on food preservation domain, blend transparent film was prepared by blending 3 wt % sodium alginate aqueous solution with 4.5 wt % konjac glucomannan aqueous solution and dried at 40^oC for 4 h. The structure and properties of the blend films were studied by infrared, wide angle X‐ray diffraction, scanning electron microscopy, and differential thermal analysis. Crystallinities of blend films were increased with the increase of sodium alginate. The tensile strength and breaking elongation of the blend films in dry state were obviously higher than those of both sodium alginate and konjac glucomannan films. Tensile strength of the dry blend film achieved 77.8 MP_a when the retention of sodium alginate in the film was 27.9 wt %. The structure analysis indicated that there was a strong interaction between konjac glucomannan and sodium alginate, and this is resulted from the intermolecular hydrogen bonds. Moisture content and degree of water swelling of the blend films were increased due to the introduction of sodium alginate. Results from the film coating preservation experiment to litchi and honey peach showed that this blend film had water‐holding ability. The fruit weight loss rate and rot rate both decreased by various values. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 617–626, 2000     

羧甲基纤维素钠/海藻酸钠共混纤维的制备与性能测试

以H2O为溶剂、CaCl2为凝固剂,采用湿法纺丝技术制得羧甲基纤维素钠(NaCMC)/海藻酸钠(NaAIg)共混纤维。通过对纺丝液的流动性以及纤维的纤度、断裂强度、断裂伸长率和吸湿性能的测试,研究了不同NaCMC添加量对共混纤维的性能的影响。结果表明:当NaCMC的相对百分含量为15%时,可得到各种性能优良的共混纤维;用生物显微镜观察到纤维表面有沟槽,横截面为圆形,边缘为锯齿状。     

Synthesis and characterization of bacterial cellulose/alginate blend membranes

Bacterial cellulose and alginate in an aqueous NaOH/urea solution were used as substrate materials for the fabrication of a novel blend membrane. The blend solution was cast onto a Teflon plate, coagulated in a 5 wt % CaCl₂ aqueous solution, and then treated with a 1% HCl solution. Supercritical carbon dioxide drying was then applied for the formation of a nanoporous structure. The physical properties and morphology of the regenerated bacterial cellulose and blend membranes were characterized. The blend membrane with 80% bacterial cellulose/20 wt % alginate displayed a homogeneous structure and exhibited a better water adsorption capacity and water vapor transmission rate. However, the tensile strength and elongation at break of the film with a thickness of 0.09 mm slightly decreased to 3.38 MPa and 31.60%, respectively. The average pore size of the blend membrane was 10.60 Å with a 19.50 m²/g surface area. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Rheology of Cellulose/Alginic Acid Blends with 1-Allyl-3-Methylimidazolium Chloride as Solvent

In this study, cellulose/alginic acid blend solutions were prepared with 1-allyl-3-methylimidazolium chloride as solvent. The effect of cellulose/alginic acid blend ratios on the rheological properties was studied. It was found that the viscosity and dynamic modulus decreased with the increase of alginic acid ratio. And the calculated viscosity values, which were obtained from the log-additivity rule, are less than the experimental viscosity values. This may be caused by the hydrogen bonding interaction between cellulose and alginic acid, which is beneficial to the miscibility of the blends. In order to prove the rheological result, cellulose/calcium alginate films were prepared from the solution, the hydrogen bonding between cellulose and alginate were investigated, which was related to the good miscibility of the blend solutions. POLYM. ENG. SCI., 60: 243–249, 2019. © 2019 Society of Plastics Engineers     

胶原蛋白/海藻酸/羧甲基纤维素共混膜的结构与性能

利用溶液共混法成功制备了新型生物膜材料—胶原蛋白/海藻酸/羧甲基纤维素共混膜(blend film),通过红外光谱、X-射线衍射、原子吸收光谱、扫描电镜对共混膜的结构进行了表征,同时测定了不同配比共混膜的透光率、拉伸强度(tensile strength)、断裂伸长率(breaking elonga-tion)、吸水率和水蒸汽透过率;对共混膜进行了热重和差示量热扫描分析。结果表明:共混膜中胶原蛋白、海藻酸钠和羧甲基纤维素之间具有较强的相互作用和良好的相容性,Ca2+交联、氢键以及静电引力等强烈相互作用使三元共混膜力学性能等得到了显著改善,其拉伸强度明显高于胶原蛋白膜、海藻酸膜和胶原蛋白/海藻酸二元共混膜、海藻酸钠/羧甲基纤维素二元共混膜,胶原蛋白质量分数为18.1%、海藻酸质量分数为45.5%和羧甲基纤维素为36.4%的三元共混膜中抗张强度最大,达102MPa。三元共混膜具有良好的力学性能,较好的热稳定性,作为一种新型生物材料可望在生物医学和食品材料领域得到应用。     

Electrospinning of heated gelatin‐sodium alginate‐water solutions

Most polymers that are electrospun are dissolved in a solvent and are spun at ambient temperature. Gelatin, a natural polymer, has excellent potential in medical applications as a biodegradable polymer, especially when combined with sodium alginate. Unfortunately, gelatin/water or gelatin/sodium alginate/water solutions cannot be electrospun at ambient temperature without the incorporation of substances that are considered potentially toxic to the human body, such as acetic acid. In this study, gelatin/water solutions with and without sodium alginate were successfully electrospun without the use of additional solvents by using heated water solutions. The effect of electrospinning parameters such as solution concentration and applied voltage on the nanofiber morphology of these solutions was studied. These nanofibers from heated gelatin/water solutions exhibited good morphology with an average size of 291 ± 67 nm at 18% concentration to 414 ± 52 nm at 20% concentration. Similar sizes were observed when sodium alginate was incorporated into the gelatin/water solutions, although the relationship was dependent upon the amount of sodium alginate in the solution as well as the total concentration. Typically, these nanofibers containing sodium alginate were produced at a lower gelatin concentration compared with the gelatin/water nanofibers because of the increase of viscosity and conductivity of the solutions due to the addition of the highly viscous and conductivity sodium alginate. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

海藻酸钙/纳米TiO_2共混纤维的制备与表征

将含固体质量分数为5%的海藻酸钠纺丝原液与纳米二氧化钛(TiO2)水分散液均匀混合,制得海藻酸钠/纳米TiO2混合纺丝原液,采用湿法纺丝,通过氯化钙凝固浴,经拉伸、水洗,制备了海藻酸钙/纳米TiO2共混纤维,研究了纳米TiO2含量对共混纤维结构及性能的影响。结果表明:纳米TiO2的加入,提高了共混纤维的力学性能;加入质量分数为0.5%的纳米TiO2,海藻酸钙大分子链上的红外特征吸收峰峰形明显变宽,共混纤维的力学性能最佳,断裂强度为2.93 cN/dtex,断裂伸长率为7.34%,优于海藻酸钙纤维;添加纳米TiO2质量分数为3%时,纳米TiO2在共混纤维中仍能较好的分散,且纤维表面光滑。加入纳米TiO2后,共混纤维的热稳定性提高。     

Controlled release of insecticide carbaryl from sodium alginate,sodium alginate/gelatin,and sodium alginate/sodium carboxymethyl cellulose blend beads crosslinked with glutaraldehyde

Interpenetrating network polymeric beads of sodium alginate (NaAlg) and its blend with gelatin (gels) or sodium carboxymethyl cellulose (NaCMC) have been prepared by crosslinking with a common crosslinking agent, glutaraldehyde (GA), for the release of insecticide carbaryl (Carb). The prepared beads were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Scanning electron microscopy confirmed the spherical nature and surface morphology of the particles. Bead characteristics, such as carbaryl entrapment efficiency, particle size, equilibrium swelling degree, and carbaryl release kinetics, were determined. The effects of the preparation conditions, such as Carb/NaAlg ratio, time of exposure to GA, blend ratio, and temperature of release medium on the carbaryl release, were investigated for 25 days at 25°C. It was observed that the carbaryl release decreased with increase in crosslinking of network, while it increased with increase in Carb/NaAlg ratio and temperature. The release of carbaryl also increased with increase in Gel or NaCMC content in the blend beads. The highest carbaryl release was found to be 100%, for the beads that were prepared with 1 : 1 NaAlg/Gel at 16 days. The diffusion coefficients have been calculated for the transport of insecticide through the polymeric beads, using initial time approximation method. These values were also consistent with the carbaryl release data. The carbaryl release from most of the bead formulations followed the Fickian trend. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1310–1319, 2006     

Adsorption of direct dye on cellulose in the presence of sodium alginate at various temperatures

Dyeing of cellulose by Chrysophenine G (CI Direct Yellow 12) in aqueous sodium alginate solution at various temperatures has been studied. The effect of temperature change on dye adsorption equilibrium to cellulose in the presence of sodium alginate has been examined based on the previously described multiple equilibrium model. The affinities of the dye, which were calculated with an interpolated ionisation degree of the carboxyl group in the cellulose and by using the ionization degree of sodium alginate measured were nearly constant under the present dyeing conditions. These results confirm the previous conclusion that the dye is concentrated into the internal solution of cellulose due to the presence of sodium alginate in the bulk solution.     

海藻酸/羧甲基纤维素共混膜的结构与性能研究

用溶液共混法制备了海藻酸/羧甲基纤维素共混膜,通过红外光谱、X-射线衍射、原子吸收光谱、扫描电镜、热分析等对共混膜的结构进行了表征,并测定了不同配比共混膜的透光率、拉伸强度、断裂伸长率、水蒸汽透过率和吸水率.结果表明:共混膜中海藻酸和羧甲基纤维素之间具有较强的相互作用和良好的相容性.共混膜具有良好的力学性能,在生物材料...