壳聚糖/PHBH复合生物降解膜的性能研究

目的研究壳聚糖(CS)与聚3-羟基丁酸酯/3-羟基己酸酯(PHBH)复合成膜后的各项性能。方法以冰乙酸为共溶剂,将CS与PHBH采用共混流延法制备成CS/PHBH生物降解复合膜。利用红外光谱仪、扫描电镜及差热分析仪等研究不同质量比CS/PHBH对复合膜力学性能、结构、热稳定性,以及生物降解性能的影响。结果壳聚糖和PHBH之间存在分子间氢键,两者间产生了一定的相互作用,同时,CS/PHBH复合膜显示出较好的热稳定性和生物可降解性。当CS和PHBH质量比为3∶1时,CS/PHBH生物降解复合膜的拉伸强度与断裂伸长率优于其他质量比的复合膜。结论当CS和PHBH质量比为3∶1时,可得到综合性能优良的复合膜。     

植物纤维在全生物降解复合材料中的应用研究进展

评述了植物纤维/聚乳酸(PLA)复合材料、植物纤维/聚-3-羟基丁酸酯(PHB)复合材料、植物纤维/3-羟基丁酸酯和3-羟基戊酸酯的共聚物(PHBV)复合材料,植物纤维/聚己内酯(PCL)复合材料、植物纤维/壳聚糖复合材料、植物纤维/淀粉复合材料、植物纤维/纤维素衍生物复合材料、全植物纤维复合材料的制备和成型方法,分析比较了材料的各种力学性能,以及为了增强材料的力学性能而进行的纤维改性.结果表明,这些复合材料具有性能优良、环境友好、可完全生物降解的特点.展望了植物纤维全生物降解复合材料未来的研究趋势.     

壳聚糖-聚羟基丁酸酯共混膜的体外血液相容性评价

制备了壳聚糖(CTS)/聚(R)-3-羟基丁酸酯(PHB)二元系列膜,扫描电镜(SEM)分析检测其表面形貌.体外评价了不同比例共混复合物的溶血率、动态凝血、复钙化时间及血小板粘附.结果表明,二元共混膜较之原料壳聚糖相比,溶血率下降,复钙化时间延长,动态凝血曲线变化缓慢.SEM显示共混膜材料表面的血小板粘附现象明显少于壳聚糖.组成为C1B1的共混材料表现突出.通过与PHB简单共混的方法可以有效改善壳聚糖的血液相容性能.     

PLGA/PCL复合材料的制备及其性能研究

在聚乳酸-羟基乙酸(PLGA)中加入聚ε-己内酯(PCL)、柠檬酸三丁酯(TBC),通过溶液共混制备了PLGA/PCL共混聚合物,通过静电纺膜及涂膜法制备了不同比表面积的降解膜,并对共混材料力学性能和膜的降解性能进行了研究。结果表明:柠檬酸三丁酯作为增容剂对整个共混聚合物的韧性和强度有明显的影响;当聚乳酸-羟基乙酸和聚ε-己内酯的质量比为80/20、增容剂柠檬酸三丁酯的用量为6%时,所得共混聚合物的断裂伸长率达到130%、冲击强度达到9.55kJ·m-2。相同条件下加入聚ε-己内酯(PCL)的膜的降解性能优于单一的聚乳酸-羟基乙酸(PLGA)膜,静电纺丝膜降解性能优于流延法膜。     

PHA/PLA生物降解共混膜的制备

采用共混改性方法,将聚乳酸添加到聚羟基脂肪酸酯中,以提高材料的力学性能和成膜性能,制备了生物降解膜。通过对原材料进行黏度测试,确定共混加工工艺的加工温度为200℃,转速为20 r/min时,共混效果较好。对共混膜进行了力学性能测试和断面结构分析,得到当PHA与PLA质量比为100∶50时,膜的拉伸强度为30 MPa,断裂伸长率为100%,共混膜的整体性能较佳。土埋降解实验显示共混膜具有一定的降解性能。     

硬脂酸对可食性膜材料性能的影响研究

为改善壳聚糖-明胶膜材料的性能,将硬脂酸加入到壳聚糖-明胶铸膜液中,制备一系列不同硬脂酸含量的三元共混膜。对其力学性能、阻氧性、阻油性、水蒸汽透过系数和透光率进行深入研究,并将其性能与壳聚糖单一膜、壳聚糖-明胶二元膜进行对比。结果表明:硬脂酸的加入对共混膜的各方面性能均产生了影响,且当壳聚糖∶硬脂酸=4∶1时,膜的各方面性能均处于最佳状态。其力学性能、阻氧性、透油系数及透光性较壳聚糖-明胶膜、壳聚糖膜差异并不显著,而其水蒸汽透过系数却得到显著的改善,为3.25E-8g·cm/(cm2·s·Pa)。     

明胶微/纳米纤维静电纺丝成型研究进展

明胶作为一种天然的可生物降解材料,因其良好的生物亲和性,广泛应用于生物医用领域.主要综述了纯明胶、明胶/聚己内酯、明胶/透明质酸、明胶/聚乙烯醇、明胶/羟基磷灰石复合体系、明胶/羟基丁酸-戊酸共聚物以及采用明胶进行材料表面改性的静电纺丝成型.     

响应面优化明胶-壳聚糖可食性复合膜的制备

目的制备明胶-壳聚糖可食性复合膜,以期为不同的实际应用提供实验数据和理论依据。方法利用明胶和壳聚糖的分子结构特点以及聚乙二醇400(PEG-400)等添加物质的性能构效关系,采用溶液浇注法制得明胶-壳聚糖复合膜,研究明胶-壳聚糖的质量分数、明胶与壳聚糖的质量比、PEG-400质量分数对复合膜性能的影响,并根据Box-Benhnke中心组合设计原理设计响应面分析试验,探讨各因素之间的交互作用,探索出明胶-壳聚糖膜的最佳工艺配方。结果膜的物理性能受明胶-壳聚糖质量分数、明胶与壳聚糖的质量比、PEG-400质量分数以及两两交互之间的影响较大。当明胶-壳聚糖的质量分数为8.5%,明胶与壳聚糖的质量比为7∶3,PEG-400质量分数为10%时,膜的拉伸强度为19.53 MPa,断裂伸长率为39.82%。结论所制作膜的透明度、光泽度、表面光滑度、气味及物理性能等各项表征均为良好。     

降解壳聚糖/明胶复合微球的制备及其对活性染料吸附性能研究

以降解壳聚糖、明胶为原料,戊二醛等试剂为交联剂,采用反相悬浮交联法制备出一系列具有高效吸附解吸功能的球形复合吸附材料降解壳聚糖/明胶复合微球,通过扫描电子显微镜,研究了原料种类以及搅拌速度对微球粒径与形貌的影响,将其用于活性染料印染废水处理中,研究了吸附温度、吸附时间、降解壳聚糖的用量及吸附液pH的大小对活性染料吸附性能的影响。结果表明:制得的降解壳聚糖/明胶复合微球的球粒径小,形态圆整,在温度为30℃、吸附时间为40min、溶液pH=4、微球制备时降解壳聚糖用量为0.4g、降解壳聚糖∶明胶质量配合比为1∶1条件下,降解壳聚糖/明胶复合微球球对活性黑WM的吸附容量达到137.25mg/g,并具有较好的循环使用价值。     

壳聚糖/明胶/苹果多酚复合膜的制备及性能研究

目的 以壳聚糖、明胶、苹果多酚为基材,制备一种具有优良性能的绿色环保复合材料。方法 用溶液共混法制备壳聚糖/明胶/苹果多酚共混膜,用土埋法测试其降解性,用红外光谱(FT–IR)、X射线衍射仪(XRD)、扫描电镜(SEM)等对其进行表征,并对其力学性能等进行测试。结果 壳聚糖/明胶/苹果多酚复合膜的机械强度随苹果多酚的添加量的增加先变大后减小,当苹果多酚添加量为1%时有较好的拉伸强度;壳聚糖、明胶、苹果多酚三者具有良好的相容性;复合膜生物降解性良好。结论 引入合适比例的苹果多酚可有效提升复合膜的力学性能,制得的可降解复合膜在绿色食品包装领域有广泛的应用前景。     

PAN/CA共混复合膜的气体分离与力学性能

聚丙烯腈（PAN）具有较高的气体渗透性,但拉伸强度低,不适宜直接制膜。为达到气体分离膜在力学强度方面的使用要求,利用PAN与乙酸纤维素（CA）共混改善其拉伸性能。结果表明,采用相转化法制备的PAN/CA共混基膜,随着CA与PAN共混比的增加,拉伸强度有明显的上升趋势,由1.74MPa增加到2.08MPa。当共混比为0....     

GAP/PET聚氨酯粘合剂胶片的制备及其性能研究

为改善聚叠氮缩水甘油醚(GAP)推进剂的力学性能,选用链段柔软的环氧乙烷/四氢呋喃共聚醚(PET),采用三羟甲基丙烷(TMP)为交联剂,异佛尔酮二异氰酸酯(IPDI)为固化剂,与GAP制备聚氨酯粘合剂胶片.实验结果表明:在R为1.9,GAP:PET:TMP羟基比为1:1:3条件下,粘合剂胶片拉伸强度为3.29MPa,延伸率为625.07%.粘合剂胶片经硝化甘油/一缩二乙二醇二硝酸酯增塑后,其力学性能变化较大.在增塑比为0.5～2.1范围内,增塑胶片的Tg符合方程:Y=-77.60233+36.45135exp(-x/0.055019).     

燃料电池用QCS键和层析硅胶膜的制备及其性能表征

以季铵化壳聚糖(QCS)和层析硅胶为原料,制备了不同硅胶含量的多孔膜。用傅里叶变换红外(FTIR)和扫描电镜(SEM)对多孔膜的结构和形貌进行表征。同时,考察了层析硅胶的用量对多孔膜的含水率(WU)、溶胀度(SR)、机械性能和电导率的影响。结果表明,随着层析硅胶含量的增加,多孔膜的含水率、溶胀度和电导率均升高,但机械性能下降。当层析硅胶的用量为40%时,多孔膜的含水率高达816%,但是膜的溶胀度仅为189%,拉伸强度为5.6MPa,断裂伸长率为4.2%;在测试温度为70℃时,不同层析硅胶含量多孔膜的电导率数值分布在2.4~3.9×10~(-2)S/cm的范围内,且随硅胶含量的增加而增加。     

The effect of cross-linking on the microstructure,mechanical properties and biocompatibility of electrospun polycaprolactone–gelatin/PLGA–gelatin/PLGA–chitosan hybrid composite

Abstract

In this study, multilayered scaffolds composed of polycaprolactone (PCL)–gelatin/poly(lactic-co-glycolic acid) (PLGA)–gelatin/PLGA–chitosan artificial blood vessels were fabricated using a double-ejection electrospinning system. The mixed fibers from individual materials were observed by scanning electron microscopy. The effects of the cross-linking process on the microstructure, mechanical properties and biocompatibility of the fibers were examined. The tensile stress and liquid strength of the cross-linked artificial blood vessels were 2.3 MPa and 340 mmHg, respectively, and were significantly higher than for the non-cross-linked vessel (2.0 MPa and 120 mmHg). The biocompatibility of the cross-linked artificial blood vessel scaffold was examined using the MTT assay and by evaluating cell attachment and cell proliferation. The cross-linked PCL–gelatin/PLGA–gelatin/PLGA–chitosan artificial blood vessel scaffold displayed excellent flexibility, was able to withstand high pressures and promoted cell growth; thus, this novel material holds great promise for eventual use in artificial blood vessels.     

Starch–chitosan hydrogels prepared by reductive alkylation cross-linking

Starch-chitosan hydrogels were produced by oxidation of soluble starch to produce polyaldehyde and subsequently cross-linked with chitosan via reductive alkylation. The swelling ratio of starch-chitosan membranes was increased gradually with increasing starch ratio, but it was always lower than the native chitosan. In dry state, starch-chitosan membranes with low starch ratio (0.16, 0.38) showed similar tensile strength values to those of native chitosan while these values decreased with increasing starch ratios (0.73-1.36). Membranes in physiological buffer solution (PBS) gave a tensile modulus between 2.8 and 1.0 MPa, decreasing with increasing starch ratio (0.16-1.36 (Wstarch/Wchitosan)). When the membranes were incubated in PBS only, a moderate weight loss was observed for the first two weeks. Original weights of low starch weight ratio membranes (0-0.38) were at near 85%, while high ratio samples (0.73-1.55) were kept around 70% after three months. However, for the membranes incubated in alpha-amylase solution, very fast weight loss was observed. For low starch ratio membranes (0.16, 0.38, 0.73), the residual original weights were measured to be 11%, 6%, 20%, while for high ratio membranes (1.04 and 1.36) these were 45% and 30%, respectively, after two months of enzyme incubation. Scanning electron microscopy analysis of alpha-amylase degraded membranes exhibited rough surface morphology.     

Microstructure and characteristic properties of gelatin/chitosan scaffold prepared by a combined freeze-drying/leaching method

A combined freeze-drying and particulate leaching method for scaffold synthesis showed an improvement in the horizontal microstructure of the gelatin/chitosan scaffolds. Type and concentration of the cross-linking agent, freezing temperature, concentration of the polymeric solution and gelatin/chitosan weight ratio were the variables affecting the scaffold properties. Assessment of the tensile properties of the scaffolds revealed that for a scaffold with 50% chitosan, glutaraldehyde, as a cross-linking agent, created much tighter polymeric network compared to N,N-(3-dimethylaminopropyl)-N′-ethyl carbodiimide (EDC). However, in the case of gelatin scaffolds, EDC was identified as the stronger cross-linker. Compressive behavior of the scaffolds satisfied formulations obtained from the theoretical modeling of the low-density, elastomeric foams. The investigation of the scaffold degradation indicated that the increase in the mechanical strength of the scaffolds would not always reduce their degradation rate.     

Preparation and bioactivity evaluation of hydroxyapatite-titania/chitosan-gelatin polymeric biocomposites

Biocomposites consisting of hydroxyapatite (HA) and natural polymers such as collagen, chitosan, chitin,and gelatin have been extensively investigated. However, studies on the combination of HA and titania with chitosan and gelatin have not been conducted yet. Novel biodegradable hydroxyapatite-titania/chitosan-gelatin polymeric composites were fabricated. In this work, our results are concerning with the preparation and characterization of HA powder and HA filler containing titania powder (10 and 30%) with a chitosan and gelatin copolymer matrix. The present research focuses on characterizing the structure of this novel class of biocomposites. Thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier Transformed Infrared Spectroscopy (FT-IR), Scanning electron microscopy (SEM-EDAX) were employed to assess the produced composites. The mechanical properties in terms of compressive strength and hardness test were also investigated. The in vitro study in simulated body fluid (SBF) was performed to assess the bioactivity of composites. The results proved that apatite resembling natural bone are formed faster and greater in the case the composite of HA containing 10% titania into chitosan-gelatin polymeric matrix when they are soaked in a simulated body fluid (SBF) than the composite containing 30% titania. The biocomposites containing HA with 10% titania are expected to be attractive for bioapplications as bone substitutes and scaffolds for tissue engineering in future.     

Properties and in vitro biological evaluation of nano-hydroxyapatite/chitosan membranes for bone guided regeneration

Nano-hydroxyapatite(n-HA)/chitosan(CS) composite membranes were prepared by solvent casting and evaporation methods for the function of guided bone regeneration (GBR). The effect of n-HA content and solvent evaporation temperature on the properties of the composite membranes was studied. The n-HA/CS membranes were analyzed by scanning electron microscopy, Fourier transformed infrared spectroscopy, X-ray diffraction, swelling measurement, mechanical test, cell culture and MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenylte-2H-tetrazolium bromide) assay. The results show that the surface roughness and micropores of the composite membranes increase with the rise of n-HA content, suitable for adhesion, crawl and growth of cells. The hydroxyapatite holds nano size and distributes uniformly in the composite membranes. Chemical bond interaction exists between Ca ions and –OH groups of n-HA and –NH₂ or –OH groups of CS. The n-HA content and solvent evaporation temperature have obvious influence on the swelling ratio, tensile strength and elongation rate of the composite membranes. Cell culture and MTT assays show that n-HA and its content can affect the proliferation of cells. The n-HA/CS composite membranes have no negative effect on the cell morphology, viability and proliferation and possess good biocompatibility. This study makes the n-HA/CS composite membrane be a prospective biodegradable GBR membrane for future applications.     

二次通用旋转组合设计法优化水溶性壳聚糖 / 纤维素复合膜的制备工艺

采用二次通用旋转试验设计,对水溶性壳聚糖/纤维素复合膜的制备工艺进行了优化,建立了复合膜的拉伸强度与水溶性壳聚糖质量分数、纤维素质量分数、甘油浓度的二次回归数学模型,并利用该模型探讨了各因素对复合膜的拉伸强度的影响。结果表明,各因素对复合膜的拉伸强度作用大小依次为纤维素质量分数>甘油质量分数>水溶性壳聚糖质量分数;水溶性壳聚糖质量分数为3.6%,纤维素质量分数为2.5%,甘油质量分数为10%时,复合膜的性能最优,在该条件下,复合膜的拉伸强度为0.801 MPa,伸长率为15.2%,且柔软度为288 mN。