聚乳酸荧光防伪纤维的耐酸碱性分析

选用L16(54)正交试验表,探讨了p H值、温度及处理时间三因素对聚乳酸荧光防伪纤维性能的影响。利用荧光光谱仪、荧光显微镜、纤维强度仪等测试仪器,分析了经酸碱处理的聚乳酸荧光防伪纤维的荧光性能和力学性能。方差分析结果表明:p H值、温度及处理时间对聚乳酸荧光防伪纤维的荧光强度的影响均不显著,纤维在荧光性能方面表现出良好的耐酸碱性和耐热性;聚乳酸荧光防伪纤维的力学性能受温度的影响显著,但p H值和处理时间对其影响不显著,随着温度的升高,聚乳酸荧光防伪纤维的断裂强度呈下降趋势。     

聚乳酸纤维的染色性能研究

本文选用不同种类的分散染料,设定不同温度、时间、p H、浴比、助剂等工艺条件,研究了聚乳酸纤维的染色性能。通过对染后纤维的表面色深值、染色牢度及断裂强力等项目的测试,优选出适宜的染料种类及工艺条件。此外,就染料结构对聚乳酸纤维染色性能的影响,及其常压染色的可行性问题进行了探讨。     

聚乳酸/丽赛/竹纤维混纺织物深色染色工艺研究

在聚乳酸纤维混纺织物的二浴法染色中,以表观色深K/S值作为衡量染色效果的依据,研究了第一浴染色工艺曲线、温度、pH值、时间对织物染色性能的影响;以染料的上染率K/S值为依据,研究了第二浴活性染料染色工艺曲线、温度、时间对织物染色性能的影响。提出了较佳的聚乳酸混纺织物深色染色配方及工艺流程。     

预处理结合纤维素酶处理对醋酯纤维降解的研究

采用纤维素酶降解经氢氧化钠预处理过的醋酯纤维,考察了pH值、温度、酶用量、处理时间以及助剂对酶解效果的影响,并初步探索了超声波对氢氧化钠预处理效果的影响。结果表明,氢氧化钠预处理后,使用纤维素酶降解醋酯纤维的工艺条件为:pH值4.5,温度55℃,酶用量3 mL/L,反应时间4 h;使用超声波辅助氢氧化钠预处理后,醋酯纤维的取代度较单一碱处理略有降低,酶解活性提高;在纤维素酶催化水解反应中,加入非离子表面活性剂可以提高醋酯纤维的酶解效果。     

熔体微分静电纺聚乳酸超细纤维膜热压增强工艺及性能研究

可降解材料高强透气纤维膜在食品、药品包装等领域需求迫切。为了解决这一问题，提出了一种聚乳酸包装膜制备技术。采用单因素实验探究了热压温度、压力和时间对熔体微分电纺聚乳酸微纳米纤维膜拉伸强度和断裂伸长率的影响；使用Design-Expert 11软件设计实验并对实验结果进行分析，利用响应面法优化纤维膜热压工艺参数，并对得到的最佳值进行了实验验证。结果表明：经响应面法优化后的最佳热压工艺参数为热压温度40℃、热压压力4 MPa、热压时间6 s，此条件处理后的聚乳酸纤维热压膜单向平均拉伸强度为27.613 MPa，相较未处理纤维膜拉伸强度提升149.89%，与预测值的相对误差为0.684%，证明拟合效果良好。热压处理可有效增强熔体微分电纺聚乳酸纤维膜的拉伸强度，提高聚乳酸纤维膜产品在包装领域的应用潜力。     

风化煤腐植酸盐缓冲性能的研究

讨论了在不同pH值和温度条件下风化煤腐植酸盐对酸碱溶液的缓冲性能。结果表明:腐植酸盐在酸碱溶液pH>6时,离解出氢离子;pH<6时则具有絮凝作用吸纳氢离子。当腐植酸盐溶液浓度为1g/L及5g/L时,对pH值在3～9范围内的酸碱溶液,腐植酸钾可以通过缓冲作用使之保持在6～7之间,而腐植酸钠可使其保持在5～6.5之间。温度相同的条件下,腐植酸盐浓度大时缓冲能力较强,达pH值稳定平衡点所需要的时间较短。腐植酸盐浓度相同时,温度高达到pH值稳定平衡点所需要的时间较短。     

风化煤黄腐酸离解平衡特性的研究

文章讨论黄腐酸分子的离解受酸度、温度、浓度的影响特性。选定温度下,在某一pH值的酸碱溶液中,加入精确称重的黄腐酸细粉,连续搅拌下测定pH值随时间变化规律,直至平衡。结果表明:1.在酸碱溶液pH>6时黄腐酸能释放氢离子、pH<5时则吸纳氢离子;对pH=4～9范围内的酸碱溶液,黄腐酸可通过缓冲作用使之保持在pH=5～6之间。2.黄腐酸浓度大时缓冲能力较强、达平衡的时间较短、且平衡时pH值较低。3.温度高时达平衡的时间较短。     

纺织用竹浆纤维在酸碱试剂下的抗菌性能研究

为探究酸碱试剂对竹浆纤维抗菌性的影响,分别选择不同质量浓度的氢氧化钠和硫酸试剂,分析其在不同处理时间与温度下对竹浆纤维抗菌性能的影响。结果显示,温度、处理时间以及试剂质量浓度不同时,竹浆纤维的抗菌性能均存在一定差异;在硫酸或氢氧化钠处理后,竹浆纤维的抑菌率大多在70%以上,且试剂处理时间对竹浆纤维抗菌能力的影响最为显著。     

豆渣中可溶性膳食纤维酶法制备工艺优化

本试验采用机械粉碎法-酶法从豆渣中提取可溶性膳食纤维,采用单因素试验和正交试验研究了豆渣粉碎目数、料水比、纤维素酶的添加量、提取时间、提取温度和溶液pH值等因素对可溶性膳食纤维得率的影响。结果表明,酶法制备豆渣可溶性膳食纤维的最佳工艺条件为:粉碎目数60、料水比1∶15、纤维素酶添加量0.7%、提取时间1.5 h、提取温度50℃和pH值5,在该工艺条件下,可溶性膳食纤维的得率为8.05%。     

秸秆纤维自生胶合纤维板性能的研究——漆酶、半纤维素酶处理对纤维板性能的影响

研究酶处理工艺对秸秆纤维自生胶合性能的影响和酶处理秸秆纤维的优化条件,为制备无甲醛自生胶粘纤维板提供实验依据。选择漆酶、半纤维素酶为处理剂,以温度、pH值、酶处理时间和酶用量为主要因素进行正交试验。结果表明,漆酶处理最佳条件为:温度45~50℃,反应时间2h,pH值为7,用量45U/g。半纤维素酶处理秸秆纤维的最佳条件:温度50℃,反应时间2~2.5h,pH值为5~6,用量15U/g。该实验为制备力学性能优良的秸秆纤维自生胶合纤维板提供了理论依据。     

聚乳酸纤维的脂肪酶表面改性处理

采用脂肪酶Lipex100L和L3126对聚乳酸(PLA)纤维进行表面处理。研究了PLA纤维处理液的pH值及紫外吸光度的变化,以及处理后PLA纤维染色性能和表面形态的变化。结果表明:脂肪酶Lipex100L和L3126均能对PLA纤维产生水解作用,L3126的水解效果优于Lipex100L;脂肪酶处理后PLA纤维经活性染料和阳离子染料染色,其表观深度较处理前明显提高;扫描电镜观察分析表明脂肪酶对PLA纤维表面产生了刻蚀作用。     

The production and characterization of poly(lactic acid) fibers dyeable with anionic dyes using octaammonium polyhedral oligomeric silsesquioxane nanoparticle

In this study, acid dyeable poly(lactic acid) (PLA) fiber was produced with the addition of octaammonium polyhedral oligomeric silsesquioxane (OA-POSS) nanoparticle during the melt spinning. The tensile, thermal and morphological properties of the fiber samples were characterized by tensile testing, differential scanning calorimetry, scanning electron microscopy and transmission electron microscopy. Two different anionic dyes, a disulphonated 1:2 premetallised acid dye and monosulphonated non-metallised, were used. The effects of dyeing conditions including dyeing temperature and time, OA-POSS concentration, anionic dye types and concentrations were investigated on the dyeability properties of the PLA fiber samples. It was concluded that the percent crystallinity and the tensile strength of pure PLA fiber decreased as the added amount of OA-POSS increased. According to the dyeing results, the addition of OA-POSS greatly improved the dyeability of the PLA fiber with anionic dyes by introducing ion–ion interaction between the terminal ammonium groups of POSS nanoparticle and the sulphonyl groups of dye molecules.     

聚乳酸/玄武岩纤维复合材料的制备及性能研究

利用混杂原理,先将玄武岩纤维与聚乳酸纤维混合制成针刺毡,再与聚乳酸树脂复合,以提高树脂基体对增强体结构的渗透和结合性能。采用正交试验法,以混杂针刺毡中聚乳酸纤维含量、复合层压压力、复合层压温度为影响因素,讨论了混杂复合层压工艺对复合材料力学性能的影响。结果表明,采用混杂复合工艺有利于复合材料力学性能的改善,且混杂纤维含量在一定范围内时,复合材料的力学性能会随着混杂纤维含量的增加而线性增强,同时复合层压压力的增加也有利于复合材料力学性能的改善;采用混杂复合工艺时,复合层压温度对复合材料力学性能的影响规律不同于传统层压复合时复合层压温度对复合材料力学性能的影响,复合层压温度过高不利于复合材料力学性能的提高。     

静电纺PLA/丝素-明胶复合纤维膜的性能研究

通过静电纺丝先制备聚乳酸(PLA)纤维膜,在PLA纤维膜上分别喷射不同比例的丝素-明胶纺丝液制得PLA/丝素-明胶复合纤维膜,对复合纤维膜的溶解性能、尺寸稳定性、力学性能及生物性能进行表征。结果表明:与丝素-明胶纤维膜相比,PLA/丝素-明胶复合纤维膜的溶失率明显下降,尺寸稳定性及柔软性得到改善,且经甲醇处理后,复合纤维膜的力学性能提高。将制备的复合纤维膜进行小鼠胚胎细胞(3T3)培养实验,3T3在PLA/丝素-明胶复合纤维膜上能更好地粘附、伸展和繁殖。     

Effects of ammonium polyphosphate and triphenyl phosphate on the flame retardancy,thermal, and mechanical properties of glass fiber–reinforced PLA/PC composites

The purpose of this study is to increase of the flammability properties of the glass fiber (GF)–reinforced poly (lactic acid)/polycarbonate (PLA/PC) composites. Ammonium polyphosphate (APP) and triphenyl phosphate (TPP) were used as flame retardants that are including the organic phosphor to increase flame retardancy of GF‐reinforced composites. APP, TPP, and APP‐TPP mixture flame retardant including composites were prepared by using extrusion and injection molding methods. The properties of the composites were determined by the tensile test, limiting oxygen index (LOI), differential scanning calorimetry (DSC), and heat release rate (HRR) test. The minimum T_g value was observed for the TPP including PLA/PC composites in DSC analysis. The highest tensile strength was observed in GF‐reinforced PLA/PC composites. In the LOI test, GF including composite was burned with the lowest concentration of oxygen, and burning time was the longest of this composite. However, the shortest burning time was obtained by using the mixture flame retardant system. The flame retardancy properties of GF‐reinforced PLA/PC composite was improved by using mixture flame retardant. When analyzed the results of HRR, time to ignition (TTI), and mass loss rate together, the best value was obtained for the composite including APP.     

乙肝表面抗原在微球表面的吸附行为、活性和结构变化

采用快速膜乳化技术结合溶剂挥发法制备了尺寸均一的聚乳酸(PLA)微球,平均粒径为800 nm左右,并采用PLA微球对乙肝表面抗原(HBsAg)进行了吸附研究,考察了pH值、盐浓度、微球用量、HBsAg浓度及吸附温度对HBsAg吸附率、活性和结构的影响. 结果表明,在pH 6.0的磷酸缓冲溶液中,NaCl浓度为20 g/L、微球用量为20 mg/mL、HBsAg浓度为10 mg/mL、吸附温度为37℃的条件下,HBsAg吸附率可达60%左右. 4℃下,pH值为8.0及NaCl浓度为1 g/L、微球用量为2 mg/mL及HBsAg浓度为300 mg/mL时,HBsAg活性保留可达98%以上.     

PLA/PCL纤维及其支架的制备与力学性能研究

将一定质量比聚乳酸(PLA)与聚己内酯(PCL)进行共混,通过熔融纺丝得到PLA/PCL初生纤维,再经过热拉伸后得到PLA/PCL纤维;利用自制模具采用手工编织的方法制备了PLA/PCL管道支架;对PLA/PCL纤维及其支架的结构与性能进行了表征。结果表明:当PLA/PCL质量比为40:60时,PLA/PCL初生纤维的综合力学性能较好;拉伸温度和拉伸倍数对PLA/PCL初生纤维的力学性能影响较大,当拉伸温度为85℃、拉伸倍数为7时,所得的PLA/PCL纤维力学性能最好;在一定温度区间内,PLA/PCL支架的支撑力随着定型温度的升高而升高,合适的定型温度应为其玻璃化转变温度至130℃之间,制备的PLA/PCL支架具有良好的弯曲性、压缩性和支撑性能,能满足支架应用的需求。     

Electrospun polylactic acid nanofiber membranes containing Capparis spinosa L. extracts for potential wound dressing applications

Capparis spinosa L. (CSL) is a medicinal plant with high antibacterial activity against a variety of pathogens and antioxidation properties. In this paper, for the first time, nanofiber membranes of polylactic acid (PLA) containing 0, 4, 7,and 10 wt% CSL ethyl acetate extract were fabricated by electrospinning. Scanning electron microscopy showed that the fiber diameter decreased after adding CSL to the PLA nanofibers. Fourier transform infrared spectroscopy confirmed that CSL was successfully incorporated in the matrix. The water contact angle test proved that the addition of CSL improved the hydrophilic properties of the material. Moreover, the addition of CSL improved the oxidation resistance of the composite fiber membrane. A burst drug release from the composite nanofibers occurred within the first 12 hr, followed by slow release over a prolonged period of time. As the concentration of CSL increased, the inhibition ability of nanofibers against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) gradually increased. In summary, due to their good mechanical, antioxidant, and antibacterial properties, CSL/PLA nanofiber membranes may possess potential applications as wound dressing materials.     

Comparison of Properties of Poly(Lactic Acid) Composites Prepared from Different Components of Corn Straw Fiber

In recent years, under the pressure of resource shortage and white pollution, the development and utilization of biodegradable wood-plastic composites (WPC) has become one of the hot spots for scholars’ research. Here, corn straw fiber (CSF) was chosen to reinforce a poly(lactic acid) (PLA) matrix with a mass ratio of 3:7, and the CSF/PLA composites were obtained by melt mixing. The results showed that the mechanical properties of the corn straw fiber core (CSFC) and corn straw fiber skin (CSFS) loaded PLA composites were stronger than those of the CSFS/PLA composites when the particle size of CSF was low. The tensile strength and bending strength of CSFS/CSFC/PLA are 54.08 MPa and 87.24 MPa, respectively, and the elongation at break is 4.60%. After soaking for 8 hours, the water absorption of CSF/PLA composite reached saturation. When the particle size of CSF is above 80 mesh, the saturated water absorption of the material is kept below 7%, and CSF/PLA composite has good hydrophobicity, which is mainly related to the interfacial compatibility between PLA and CSF. By observing the microstructure of the cross section of the CSF/PLA composite, the research found that the smaller the particle size of CSF, the smoother the cross section of the composite and the more unified the dispersion of CSF in PLA. Therefore, exploring the composites formed by different components of CSF and PLA can not only expand the application range of PLA, but also enhance the application value of CSF in the field of composites.