有机蒙脱土/聚氨酯弹性体复合材料的微观形貌及力学性能

以十八烷基三甲基氯化铵（OTAC）为改性剂,通过离子交换法改性钠基蒙脱土（MMT）制得有机蒙脱土（OMMT）;以聚丙二醇（PPG）和4,4'-二苯基甲烷二异氰酸酯（MDI）为单体,1,4-丁二醇（BDO）为扩链剂,合成聚氨酯弹性体（PUE）基体;并采用预聚体法制备了OMMT/PUE复合材料。FTIR和XRD测试结果表明:OMMT在2 921 cm-1和1 469 cm-1处出现-CH₂吸收峰,表明OTAC分子链成功插入到OMMT片层,由OMMT的耐热性推算OTAC的插层量为24%,且OMMT的层间距较MMT增加了0.7 nm。OMMT/PUE复合材料的SEM和XRD结果显示:适量的OMMT在PUE基体中均匀分散,且以完全剥离的形式存在,其主要原因是:一方面由于OTAC分子与PUE软链间存在较强的作用,另一方面OMMT表面活性基团与基体间也存在一定的界面作用,两种作用均有利于提高OMMT/PUE复合材料的力学性能。力学性能测试结果表明:当OMMT的含量为3wt%时,OMMT/PUE复合材料的拉伸强度、扯断伸长率及断裂拉伸强度比PUE分别提高了37%、28%和34%,力学性能得到明显改善。      

有机蒙脱土插层脲醛（OMMT／UF）树脂的制备与性能研究

实验采用十六烷基三甲基溴化铵(CTAB)和十二烷基三甲基溴化铵(DTAB)为改性剂,对蒙脱土(MMT)进行了有机化处理,得到了有机蒙脱土(OMMT),并采用聚合反应过程中的插层复合法制备了有机蒙脱土插层脲醛树脂(OMMT/UF)胶粘剂。通过XRD和SEM对OMMT的结构变化进行表征,结果表明:有机改性剂已进入OMMT的层间,OMMT具有较MMT优良的层间结构。考察了OMMT的投加量对OMMT/UF胶粘剂的各项性能的影响,结果表明OMMT加入量越大,越有利于增强除固化时间以外的各项性能,与UF胶粘剂相比,当OMMT质量分数为3%~5%时,得到的OMMT/UF胶粘剂的表观粘度提高了2倍,耐水时间增加了100 min左右,甲醛释放量降至了5.6 mg/L以下,但是固化时间则增加了近1倍。将OMMT/UF胶粘剂用于胶合板的压制,发现OMMT/UF胶粘剂能够改善板材的强度,同时减少板材甲醛的释放。     

有机改性蒙脱土的制备及其对聚乙烯-聚苯乙烯相态和力学性能的影响

利用Gemini表面活性剂对蒙脱土进行插层改性制备得到有机改性蒙脱土（OMMT）,采用溶液混合法制备了OMMT/聚苯乙烯（PS）母料,将OMMT/PS母料与聚乙烯（PE）熔融共混制备得到OMMT/PS-PE复合材料。研究了蒙脱土的插层改性对OMMT/PS-PE复合材料相形态和力学性能的影响。对OMMT进行FTIR、XRD、TG表征,结果表明Gemini表面活性剂成功插层进入蒙脱土层间。通过SEM和电子万能试验机研究了OMMT/PS-PE复合材料相结构、分散相粒径的及相态与力学性能之间的关系。结果表明,随着OMMT含量的增加,PS分散相的粒径逐渐减小;当OMMT含量为2.5wt%时,OMMT/PS-PE复合材料的相形态由“海-岛”转变为双连续结构。与未添加OMMT的PE-PS树脂相比,OMMT/PS-PE复合材料弯曲模量和断裂伸长率显著提高,分别提高了约18%和近50倍。      

β-CaSiO_3/丝素蛋白复合支架材料结构与性能的研究

利用冷冻干燥法制备了β-CaSiO_3/丝素蛋白复合支架材料,经XRD和FTIR分析表明复合支架中丝素的结构主要以β-折叠为主;SEM分析显示材料孔隙分布均匀,孔连通性较好,孔径尺寸约为100～300μm.对支架的孔隙率和机械强度等性能进行了表征,研究表明复合支架的孔隙率为83%～87%,机械强度有较大提高.应用模拟体液浸泡实验研究了复合支架的体外生物活性,并用XRD、FESEM和EDS对试样表面进行了表征;结果显示,样品经模拟体液浸泡3天后,表面都能沉积出类骨羟基磷灰石(HA)层,β-CaSiO_3的加入能加快复合支架表面沉积类骨HA的速度.研究结果显示β-CaSiO_3/丝素蛋白复合支架材料有望作为强度较好的生物活性硬组织修复材料.     

Preparation and properties of poly HTBN-based urethane--urea/organo reactive montmorillonite nanocomposites

With ultrasonic assistant mixing way, an intercalated mixture of polyol/organo reactive montmorillonite (ORMMT) was pretreated. The prepolymer composed MMT clay was prepared by reaction of polyol/ORMMT mixture with toluene diisocyanate (TDI). The resultant prepolymer reacted with extender (DMTDA) and then the polyurethane--urea/organo reactive montmorillonite (PUU/ORMMT) nanocomposites were obtained. The structure, morphology and properties of PUU/ORMMT nanocomposites were characterized by FT-IR, TEM, AFM, strain-stress machine, TGA, and dynamic mechanical analysis (DMA). The results showed that when the OMMT content is 3%, the PUU/ORMMT nanocomposities performed super mechanical properties. Because of the presence of ORMMT, both T_g of the soft segment and tanδ of the PUU increased, and the decomposition temperature for the first step and the second step increased respectively. TEM images showed that the organophilic MMT particles in the PUU composite exhibit a high degree of intercalation and exfoliation.     

Flammability,thermal and physical-mechanical properties of cationic polymer/montmorillonite composite on cotton fabric

The flammability, thermal and mechanical properties on cotton fabric were improved by being finished with the composite containing montmorillonite. To this aim, polymer dimethyl diallyl ammonium chloride-allyl glycidyl ether (P_DMDAAC-AGE) was prepared and its structure characterized by Fourier transform infrared (FT-IR) and Nuclear magnetic resonance (¹H NMR). The quaternary ammonium salt copolymer/montmorillonite composite (P_DMDAAC-AGE/MMT) was obtained by polymer intercalation method. The X-ray diffraction (XRD) indicated that the MMT interlayer spacing increased after the polymer intercalation. Composite materials were loaded onto the cotton fabrics by a dip-pad-dry method. The thermo gravimetric analysis (TGA), vertical flame test and limiting oxygen index (LOI) results showed that the thermal and flammability properties of the cotton fabric were improved after it was finished with the composite. Tensile testing revealed an increase on mechanical properties of the finished fabric, but the physical properties hardly changed from the bending length and whiteness results. Scanning electron microscope (SEM) and energy disperse X-ray spectroscope (EDX) results verified the improvement of those properties due to the presence of montmorillonite in the composite.     

有机硅丙烯酸酯/蒙脱土纳米复合乳液的制备及表征

以十二烷基苯磺酸(DBSA)为插层剂改性蒙脱土(MMT),制得了有机蒙脱土(OMMT)。采用原位插层聚合法,以OMMT、八甲基环四硅氧烷、乙烯基三甲氧基硅烷以及甲基丙烯酸酯甲酯、丙烯酸丁酯和丙烯酸为原料,制备了有机硅丙烯酸酯/蒙脱土纳米复合乳液。考察了OMMT用量对乳胶粒径及乳胶膜性能的影响,并对OMMT及乳胶膜的结构进行了表征。结果表明:当OMMT的用量为2.0%时,乳胶粒子尺寸为纳米级,乳胶膜的耐热性以及各项物理机械性能均得到明显改善。XRD分析表明,MMT变为OMMT后,其层间距从1.23nm增大至1.54nm。FT-IR分析表明,有机硅和丙烯酸酯单体在OMMT层间发生接枝聚合反应。     

Synthesis and characterization of gelatin based polyester urethane scaffold

For tissue engineering purpose two gelatin based polyester urethane scaffolds of different compositions were prepared from lactic acid, polyethylene glycol 400 (PEG 400) and characterized by FTIR, XRD for their mechanical and morphological properties using SEM and optical microscopic analyses. Degradation and swelling studies of gelatin based polyester urethane scaffolds in phosphate buffer saline (PBS) were performed. Human keratinocyte cells were cultured within these scaffolds, which showed good cell adherence and proliferation.     

壳聚糖/羟基磷灰石表面修饰聚己内酯多孔骨支架的制备及性能

采用选择性激光烧结技术构建多孔聚己内酯(PCL)骨支架,用原位合成的方法制得壳聚糖/羟基磷灰石(CS/HA)悬浮液,并采用真空浸泡、低速离心和冷冻凝胶的方法使CS/HA黏附在PCL支架的表面,以改善骨支架的生物相容性和细胞增殖活性。通过X射线衍射(XRD)和扫描电子显微镜(SEM)观测复合支架的物相和形貌,测量支架的压缩强度和杨氏模量,测量支架表面的水接触角,并通过体外细胞实验研究复合支架的生物学性能。实验结果表明,原位合成的方法制得了羟基磷灰石(HA);CS/HA凝胶与PCL骨支架表面黏附良好;CS/HA改善了PCL支架表面的亲水性,提升了骨支架的生物相容性和细胞增殖活性。     

蒙脱土有机改性对丁基橡胶复合材料微观结构与性能的影响

采用季铵盐有机改性蒙脱土(OMMT)与丁基橡胶(IIR)机械共混和硫化制备成复合材料。研究了蒙脱土有机改性前后对复合材料的微观结构、力学和芥子气防护性能的影响。透射电镜(TEM)和X射线衍射(XRD)显示IIR/OMMT复合材料为插层型纳米复合材料,而IIR/MMT为未插层的微米复合材料。复合材料的微观结构和填料的界面活性对其力学性能影响重大,IIR/OMMT复合材料的力学性能明显优于IIR/MMT复合材料的力学性能。添加有机或无机蒙脱土都可使芥子气在丁基橡胶中的扩散系数显著降低。而芥子气在IIR/OMMT中的扩散系数更低,这显示出IIR/OMMT复合材料的芥子气防护性能更加优异。     

聚甲基丙烯酰亚胺/有机蒙脱土泡沫的制备与性能

以甲基丙烯酸(MAA)和丙烯腈(AN)为单体,以偶氮二异丁腈(AIBN)为引发剂,以有机改性蒙脱土(OMMT)为填料,通过单体原位插层聚合的方法,制备了聚甲基丙烯酰亚胺/有机蒙脱土(PMI/OMMT)泡沫。通过傅里叶变换红外(FT-IR)和X射线衍射(XRD)对OMMT的结构进行表征,通过热重分析(TGA)、动态力学热分析(DMA)、垂直燃烧、极限氧指数(LOI)和扫描电镜(SEM)对PMI/4OMMT泡沫热性能、燃烧性能和形貌进行表征,同时对PMI/4OMMT泡沫的力学强度进行分析。结果表明,十六烷基三甲基溴化胺(CTMAB)插层进入钠基蒙脱土(Na-MMT)层间,使层间距由1.25nm增加到2.20nm。制备的PMI/4OMMT泡沫具有良好的成炭性能和较高的玻璃化转变温度,OMMT的加入提高了PMI/4OMMT泡沫的LOI,泡沫呈蜂窝状结构,孔径在0.1~0.4mm之间。力学性能分析表明,PMI/4OMMT泡沫具有较高的力学强度,PMI60/4OMMT泡沫的拉伸强度、弯曲强度和压缩强度分别为1.45MPa、2.11MPa和3.15MPa。     

新型人工髓核材料 &mdash|&mdash|&mdash|果胶/聚乙烯醇复合水凝胶的制备及其溶胀性能

利用低频振荡、 冻融法制得果胶/聚乙烯醇复合 (Co PP) 水凝胶 , 采用红外光谱仪、 差示扫描量热仪、X射线衍射仪、 扫描电镜 , 表征其结构; 观察 Co PP水凝胶的溶胀性能 , 并探讨扩散模式及溶胀动力学。结果表明: Co PP水凝胶是一种多孔材料、 有两个结晶区 , 脱水后可再次水合、 溶胀 ; 水分子以菲克扩散模式渗入 Co PP水凝胶 , Co PP水凝胶的溶胀速率常数、 溶胀平衡时的质量溶胀率 (197. 38 %～252. 49 %) 、 体积溶胀率 (241.47 %～308. 93 %) , 均大于聚乙烯醇 ( PVA) 水凝胶。因此 , Co PP水凝胶具有溶胀快和溶胀率大等特点 , 可减小人工髓核假体植入时的尺寸 , 利于微创手术植入。     

聚氨酯弹性体/有机蒙脱土纳米复合材料合成和性能

采用性能优异的有机插层剂对蒙脱土(MMT)进行改性,制备有机化蒙脱土(OMMT)。通过单体插层法合成了聚氨酯弹性体(EPU)/OMMT纳米复合材料;采用红外光谱(FTIR)、X衍射(WAXD)、透射电镜(TEM)等手段分析了材料结构,并比较了该纳米复合材料的物理机械性能。     

气液相聚合制备蒙脱土/聚吡咯的结构特征及其导电性能

以FeCl₃为氧化剂,与钠基蒙脱土(MMT)以不同比例进行离子交换后所得悬浮液与吡咯(Py)单体进行气液相聚合,制备出蒙脱土/聚吡咯(MMT/PPy)复合材料。XRD、FTIR和SEM分析表明,Py单体在MMT的片层间发生了聚合反应,MMT的层间距随PPy含量增加不断变大。MMT/PPy复合材料呈现出 MMT和PPy的红外特征吸收峰,但某些吸收峰出现蓝移。SEM 观察显示MMT/PPy呈片状形态特征。当其中的MMT去除后,PPy仍为片状结构,与纯 PPy的球粒形貌不同。电导率测试表明,MMT/PPy复合材料的电导率随PPy含量增加而提高,至40.9 wt% PPy含量时,MMT/PPy的电导率已达到PPy 的电导率水平(10-1S/cm),含54.3 wt% PPy的MMT/PPy电导率甚至略高于PPy。     

卵磷脂/蒙脱土纳米中间体的制备及血液相容性研究

通过插层技术合成了卵磷脂/蒙脱土(PC/MMT)纳米中间体,利用XRD、FT-IR对合成的卵磷脂/蒙脱土纳米中间体进行了表征,结果表明卵磷脂已进入了蒙脱土层间,其层间距高达6.13nm;通过溶血试验和血浆复钙试验评价了PC/MMT纳米中间体的血液相容性,试验结果表明PC/MMT纳米中间体的溶血率<5%,符合生物医学材料的标准,复钙时间较长,有良好的血液相容性;预示了其在生物医药领域的潜在应用性.     

蒙脱土/聚苯乙烯复合材料的热分解成炭行为

将聚苯乙烯(PS)树脂与不同种类蒙脱土(MMT)进行熔融复合制备MMT/PS复合材料, 通过X射线衍射(XRD)和高分辨透射电镜(HRTEM)对复合材料的微观结构进行了研究。采用SEM、 EDX、 XRD、 氧指数法和锥形量热法研究了复合材料的热分解成炭行为和燃烧性能。结果表明: 用蒙脱土原土(NaMMT)制备的NaMMT/PS复合材料是一种简单物理混合物, 用有机蒙脱土(OMMT)制备的OMMT/PS复合材料是一种插层-部分剥离型纳米复合材料。MMT与PS质量比为6:100时, OMMT/PS复合材料的热释放速率峰值和平均值分别只有NaMMT/PS复合材料相应值的70.7%和67.4%, 火灾性能指数(FPI)是后者的1.2倍, 氧指数比后者增加1.0%, 热分解残余物表面碳元素含量是后者的2.5倍。OMMT/PS复合材料热分解后在材料表面生成一层厚厚的致密、 连续的含碳硅酸盐残余物层, 起到良好的阻燃作用, 而NaMMT/PS复合材料几乎没有成炭能力, 其热分解产物全部来自NaMMT本身的热分解, 阻燃性能很差。     

Preparation and characterization of oxidized alginate covalently cross-linked galactosylated chitosan scaffold for liver tissue engineering

Liver tissue engineering (LTE) requires a perfect extracellular matrix (ECM) for hepatocytes culture to maintain high level of liver-specific functions. Here, we reported a LTE scaffold derived from oxidized alginate covalently cross-linked galactosylated chitosan via Schiff base reaction, without employing any extraneous chemical cross-linking agent. The structure of galactosylated chitosan (GC) and oxidized alginate was confirmed by Fourier transformed infrared (FTIR) spectra, proton nuclear magnetic resonance (¹H-NMR) spectroscopy, X-ray diffraction (XRD) or thermogravimetric (TG) analysis. The structure and properties of a series of the scaffolds were characterized by FTIR, XRD, scanning electron microscopy (SEM), porosity, equilibrium swelling, mechanical properties, thermal stability and in vitro degradation. FTIR spectra confirmed the characteristic peak of Schiff base groups in the scaffolds and XRD indicated the scaffolds could be amorphous. SEM analysis showed that the scaffolds displayed highly porous surfaces with average pore size of 50-150 μm and interconnected pore structure in the internal structure with average pore size of 100-250 μm. Porosity measurement suggested the scaffolds had a porosity of about 70%. The compressive modulus of the scaffolds (hydrated) was in the range of 4.2-6.3 kPa. Further studies showed that, with the increase of the oxidized alginate content, the equilibrium swelling and in vitro degradation rate of the scaffolds decreased and the thermal stability slightly increased, which might mainly attribute to the difference of the degree of cross-linking and the nature properties of the raw materials. Additionally, the biocompatibility of the scaffolds was evaluated in vitro. The results showed that the hepatocytes cultured on the scaffolds had a typical spheroidal morphology, formed multi-cellular aggregates and presented perfect integration with the scaffolds, which suggested that the scaffolds may be potential candidates for LTE strategies.     

PBS-SF核-壳结构复合超细纤维膜的制备及性能

利用同轴静电纺丝方法, 制备聚丁二酸丁二酯(PBS)-丝素蛋白(SF)核-壳结构复合超细纤维膜, 并对复合超细纤维膜进行FE-SEM、 TEM形态表征, 分析了内层纺丝流率对纤维形貌的影响; 通过FTIR和XRD测试, 比较了甲醇处理前后复合超细纤维膜分子结构和结晶性能的变化, 并进行力学性能测试。结果表明: 通过对纤维核层PBS、 壳层SF和横截面的观察, 复合超细纤维有明显的核-壳结构, 可以清晰看出纤维的核层PBS和壳层SF; 随着核层纺丝流率的增大, 超细纤维的平均直径增大; 甲醇处理后, 复合超细纤维膜中壳层SF分子结构由无规构象转变为β-折叠构象, 复合超细纤维膜核层衍射吸收强度减小, 但整个核-壳结构复合超细纤维膜结晶性能无明显变化; 甲醇处理后拉伸破坏应力从14.9 MPa增大到17.2 MPa, 但拉伸破坏应变从96.8%减小到81.8%。      

Preparation, characterization and in vitro biological study of biomimetic three-dimensional gelatin–montmorillonite/cellulose scaffold for tissue engineering

This work focused on studying the effect of blending gelatin (Gel) with Cellulose (Cel), in the presence of montmorillonite (MMT), on the swelling behavior, in vitro degradation and surface morphology. Additionally, the effect of the prepared biocomposites on the characteristics of the human osteosarcoma cells (Saos-2), including proliferation, scaffold/cells interactions, apoptosis and their potential of the cells to induce osteogenesis and differentiation was evaluated. The crosslinked biocomposites with glutaraldehyde (GA) or N,N-methylene-bisacrylamide (MBA) was prepared via an intercalation process and freeze-drying technique. Properties including SEM morphology, X-ray diffraction characterization and in vitro biodegradation were investigated. The successful generation of 3-D biomimetic porous scaffolds incorporating Saos-2 cells indicated their potential for de novo bone formation that exploits cell–matrix interactions. In vitro studies revealed that the scaffolds containing 12 and 6% MMT crosslinked by 5 and 0.5% GA seem to be the two most efficient and effective biodegradable scaffolds, which promoted Saos-2 cells proliferation, migration, expansion, adhesion, penetration, spreading, and differentiation, respectively. MMT improved cytocompatibility between the osteoblasts and the biocomposite. In vitro analysis indicated good biocompatibility of the scaffold and presents the scaffold as a new potential candidate as suitable biohybrid material for tissue engineering.     

淀粉/PVA复合膜的制备及血液相容性

在无化学处理的条件下制备出淀粉/聚乙烯醇(PVA)复合膜, 进行了力学性能、 溶胀度及红外光谱测试, 并通过溶血试验、 动态凝血试验、 血小板消耗试验对复合膜的血液相容性进行了表征。研究结果表明, 通过共混改性把淀粉引入到PVA中, 改善了力学性能和血液相容性。当PVA与淀粉的质量比为4∶1时, 复合膜的抗拉强度为13.73 MPa, 抗拉应变率为43.07%, 性能最佳。