聚苯硫醚纳米纤维的制备及其结构性能研究

以聚苯硫醚(PPS)、聚酰胺6(PA6)为原料,采用共混熔融纺丝法制备出PPS/PA6共混海岛纤维,用甲酸溶解剥离基体相PA6,制得纳米PPS纤维;研究了PPS/PA6共混体系的流变性能以及PPS含量、螺杆转速对共混物及PPS纳米纤维的结构、性能的影响。结果表明:PPS/PA6共混物的纺丝温度为290℃;随着PPS含量增加,共混物中PPS岛相直径增加,分布变宽,PPS质量分数应小于60%;当共混物中PPS质量分数由20%增至55%时,PPS纳米纤维平均直径由104 nm升至150 nm;加工过程中,适当提高螺杆转速有利于PPS纳米纤维直径细化和均匀化,当螺杆转速由20 r/min增至60 r/min时,其平均直径由180 nm降至122nm;PPS与PA6共混后,两种聚合物结晶速率均提高,且得到的PPS纳米纤维结晶度约22%,高于纯PPS纤维的结晶度。     

LDPE/PA6海岛复合超细纤维的可纺性及性能研究

采用熔融复合纺丝法制备了低密度聚乙烯(LDPE)/聚己内酰胺(PA6)海岛复合超细纤维,讨论了纺丝温度、海岛比例和纺丝速度对纤维的可纺性、结构和性能的影响。结果表明:在纺丝温度为278℃,LDPE/PA6质量比为50/50,45/55,40/60,35/65,30/70,冷却长度为140 mm,纺丝速度为1 000 m/min时,海岛复合纤维具有良好的可纺性和海岛结构,其超细纤维线密度为0.077~0.110 dtex;在PA6质量分数为55%条件下,提高纺丝速度,PA6超细纤维的直径进一步降低,力学性能增加,但不匀率上升。     

溶剂对静电纺PA6纤维可纺性的影响

分别用甲酸、六氟异丙醇(HFIP)或甲酸与醋酸(HAc)、N,N-二甲基甲酰胺(DMF)、HFIP的混合溶剂溶解聚己内酰胺(PA6),通过静电纺丝法制备了纳米级的PA6纤维。结果表明:甲酸作为溶剂时,PA6可纺丝溶液质量分数为8%～22%,所纺出的PA6纤维直径为50～300 nm;HFIP作为溶剂时PA6可纺丝溶液质量分数为8%～18%,纤维直径为50～500 nm;甲酸与HFIP,HAc,DMF的混合溶剂对纺丝状态及纤维直径分布的影响均表现为随第2种溶剂的加入,纤维直径的分布变广,平均直径增加;HAc的加入能提高PA6溶液的可纺性。     

LDPE熔体粘度对PA6/LDPE超细纤维形貌的影响

以PA6/LDPE非相容体系进行共混纺丝,得到以PA6为分散相,LDPE为连续相的基体微纤型结构,用有机溶剂甲苯溶除LDPE制得PA6的超细纤维,并用扫描电镜(SEM)研究了其形貌。结果表明,在PA6/LDPE共混物中,PA6均匀分散在连续相LDPE形成海岛结构,且分散相尺寸较小,所制得的PA6超细纤维直径也较小;熔体粘度较低的LDPE更易溶于甲苯溶剂,且更易得到含PA6更高组成比的超细纤维。     

电极丝静电纺制备聚酰胺纳米纤维膜

利用无针头电极丝式静电纺丝机制备聚酰胺(PA6)纳米纤维膜材料。研究了静电纺工艺条件对PA6纳米纤维膜形貌及直径的影响,探讨了纤维膜力学性能与直径的关系。结果表明,电极丝静电纺丝装置能高效制备光滑、连续、均匀的纳米纤维膜;纤维直径与纺丝液质量分数呈正比关系,质量分数在12%左右时静电纺丝效果最好;当电压为70 k V时,纤维直径最小且分布较集中;接收距离的增加改善纤维直径的均匀性;直径的减小提高膜断裂强度的同时也降低伸长率。     

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。     

PET-PA/PA6共混纤维的酸性染料染色性能

为开发酸性染料可染改性聚酯(PET)纤维,将不同共聚比例的PET-聚酰胺(PA)共聚物与聚己内酰胺(PA6)以不同共混比例共混纺丝,制备PET-PA/PA6共混纤维,研究了PET-PA/PA6共混物的热性能、可纺性及共混纤维的酸性染料染色性能。结果表明:PET-PA/PA6共混物中,PET-PA与PA6在无定形区是部分相容的;PET-PA/PA6共混物具有良好的可纺性,其中PA嵌段和PA6共混质量分数均为20%(PET-PA-20/PA6-20)的共混纤维的断裂强度2.54 c N/dtex、断裂伸长率31.0%,满足后续加工的要求;PA嵌段和PA6共混质量分数均为10%(PET-PA-10/PA6-10)共混纤维采用酸性染料染色时,染浴p H值应控制在4.5~5.5;升高温度和延长染色时间都能提高PET-PA-10/PA6-10共混纤维的染料上染率;随PET-PA/PA6着共聚物中PA嵌段比例的增加,共混纤维染料上染率迅速增大,PET-PA-20/PA6-20共混纤维在100℃时,酸性染料上染率可达到99.03%。     

PVP/FF复合纳米纤维的制备与表征

采用静电纺丝技术制备了聚乙烯吡咯烷酮/二苯基丙氨酸(PVP/FF)复合纳米纤维;考察了FF含量、纺丝液流速对电纺纤维形貌及其平均直径的影响;利用扫描电镜对纤维表面形态进行了观察,通过X射线衍射和热重分析考察了纳米纤维中FF的存在状态及纳米纤维的热稳定性;通过全反射红外光谱分析了FF与PVP之间的相互作用。结果表明:当复合纤维中FF质量分数小于2%时,共混溶液的可纺性较好;复合纳米纤维直径随着FF含量的增大而先减小后增加,当FF的质量分数增加到5%时,复合纳米纤维的直径也相应增大;随着纺丝液流速的增大,复合纳米纤维的直径有逐渐增大的趋势,当纺丝液流速在0.2～0.6mL/h时,复合纳米纤维形貌较佳,纤维直径分布均匀,表面光滑无颗粒;PVP/FF复合纳米纤维中FF与PVP发生复合作用处于分散的无定形状态,分解温度范围变宽;FF与PVP之间具有良好的相容性。     

高流动性PA 6超细纤维的制备及其性能研究

采用自制的高流动性聚己内酰胺(HPA 6)、普通聚己内酰胺(PA 6)、低密度聚乙烯(LDPE)为原料,通过共混纺丝法分别制备HPA 6/LDPE定岛纤维和HPA 6/PA 6/LDPE不定岛纤维,溶解去除LDPE,得到一系列HPA 6超细纤维;研究了HPA 6的可纺性及其超细纤维的线密度、力学性能、染色性能等。结果表明:由于HPA 6在纺丝温度下较好的流动性和高支化结构及大量末端基团,HPA 6可纺性良好;HPA 6/LDPE质量比为70/30时,157.4 dtex/36 fHPA 6超细纤维断裂强度为3.85 c N/dtex,断裂伸长率为14%,染色深度为1.809,色牢度达5级;HPA 6超细纤维的力学性能和染色性能优异,与PA 6超细纤维性能相当,可拓展其在纤维领域的应用。     

芳香族支链聚酰胺6的制备及共混纺丝研究

通过添加均苯四甲酸二酐水解聚合工艺制备芳香族支链聚酰胺6(PA6),采用熔融共混制备芳香族支链PA6/Ti O2母粒,然后与线型PA6共混纺丝,经拉伸后得到含芳香族支链PA6的共混纤维;研究了均苯四甲酸二酐含量对芳香族支链PA6流动性及热学性能的影响,以及芳香族支链PA6对芳香族支链PA6/Ti O2共混物结晶行为、可纺性及纤维力学性能等的影响。结果表明:随着均苯四甲酸二酐含量的添加,芳香族支链PA6的相对黏度逐渐降低,熔体流动指数增大,流动性增加,而结晶熔融温度逐渐降低;含芳香族支链PA6的共混体系纺丝温度较纯PA6降低4℃,芳香族支链PA6有助于提高PA6的可纺性,且纤维力学性能较好,含质量分数8%芳香族支链PA6的共混纤维的断裂强度为2.8 c N/dtex,断裂伸长率为45.4%。     

Fabrication and properties of poly(l‐lactide) nanofibers via blend sea‐island melt spinning

Poly(l ‐lactide) (PLLA) nanofibers were prepared by melt extrusion of immiscible blends of PLLA/low density polyethylene (LDPE) and subsequent removal of the LDPE matrix from the blend fibers. The effect of blends composition and draw ratio on the phase structure of the blend fibers, crystallization, mechanical properties, and the diameter of the PLLA nanofibers was investigated. It is found that the diameter of the PLLA phase gradually increases with the increase of PLLA content. With the variation of PLLA content from 50 to 60 wt %, the average diameter of acquired PLLA nanofibers changes from 119 to 153 nm under the draw ratio of 1.5. When further increasing the content of PLLA to 65%, it is difficult to acquire PLLA nanofibers due to the poor dissolving properties between PLLA and LDPE components. Oriented PLLA nanofibers with the average diameter of 92 nm can be fabricated from PLLA/LDPE (50/50, wt %) blends under the draw ratio of 2. The present results suggest that it is possible to acquire polymer nanofibers with high output using blend sea‐island melt spinning. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41228.     

PES/PA6的共混纺丝及其性能研究

将不同质量比的聚醚砜(PES)与聚酰胺6(PA6)共混进行熔融纺丝制得PES/PA6共混纤维;研究了共混物的流动性及其纺丝工艺,以及PES/PA6共混纤维的热稳定性和力学性能。结果表明:PA6的加入显著提高了PES的流动性,降低了纺丝温度,改善了PES的可纺性;与纯PES纤维相比,PES/PA6共混纤维的起始热分解温度有所降低,PES/PA6质量比为70/30～30/70的PES/PA6共混物的纺丝温度为320～340℃,卷绕速度为100～400 m/min,纤维的断裂强度为0.71～2.25 cN/dtex。     

Effects of varying melt flow rates on laser melt-electrospinning of low-density polyethylene nanofibers

The ultimate functionality and applicability of polymeric nanofibers are mainly to subject on its diameter. This study explores the influence of melt flow rates (MFRs) of low-density polyethylene (LDPE) on the diameter of laser melt electrospun nanofibers. Ethylene-vinyl alcohol (EVOH) copolymer was added to the nonpolar LDPE as a spinning aid. After electrospinning, the EVOH was removed from LDPE/EVOH blend fiber by treating with isopropanol/water solution and LDPE nanofiber was obtained with a diameter of only 190 ± 85 nm for the highest MFR. A linear diameter reduction was observed for pure LDPE and EVOH removed LDPE fiber with the increase of MFR. However, a slight diameter increment was reported for the LDPE/EVOH blend fiber with higher MFR due to the improved melt viscosity of the component. A massive diameter decrement was found after EVOH removal from the blended fiber, resulting in the renovation of microfiber to a stable nanoscale dimension.     

静电纺丝制备蛋清蛋白/聚氧化乙烯纳米纤维

本研究采用去离子水为溶剂,以蛋清蛋白与聚氧化乙烯（PEO）混合进行静电纺丝制备纳米纤维,采用扫描电镜表征了蛋清蛋白/PEO纳米纤维的形貌特征,探究了溶液质量分数以及纺丝工艺参数对蛋清蛋白/PEO纤维形貌的影响,并采用元素分析测试表征了纤维的元素组成成分。实验结果表明,蛋清在质量分数20%~80%之间表现出可纺性,蛋清质量分数50%的纺丝溶液进行纺丝,在纺丝电压25kV、纺丝距离16cm、挤出速度0.2mL/h的条件下,可纺性最好,制备的纤维无珠串平均直径为389nm,且纳米纤维中11.02%为氮元素,说明蛋清中的蛋白质成功转化为了纳米纤维。蛋清蛋白具有生物友好、可降解、来源广泛等优点,本研究成功实现了蛋清蛋白纳米纤维绿色制造,为其在生物医药、电池催化等领域的应用提供了基础。     

Rheological behavior of ultrahigh molecular weight polyethylene/low‐density polyethylene blending gels with high solid content

For developing polyethylene (PE) fibers with relatively high mechanical properties but low cost, the rheological behaviors of ultrahigh molecular weight polyethylene (UPE) and low density polyethylene (LDPE) blending gels (UL blending gels) were investigated in terms of the shear‐induced chain interactions and the sol–gel transitions. UL blending gels with a fixed blend ratio 1/1 of UPE and LDPE but different solid contents (SCs) ranging from 2 wt% (UL‐2) to 10 wt% (UL‐10) were prepared using paraffin oil as solvent. The UL‐10 showed a more significant shear thinning behavior than others, and exhibited a little bit lower apparent viscosity than UPE gel with 5% SC (UPE‐5) at elevated temperature even though the SC of UL‐10 is double of that of UPE‐5. UL blending gel with low apparent viscosity and high SC could ensure smoothly and high‐efficient spinning. Rheological measurements confirmed no significant solid‐liquid phase separation of the system of UPE and LDPE in paraffin oil. At the same time, the macromolecular orientation under shear and structural viscosity also assured the blending gel UL‐10 an excellent spinning performance. UL blending fibers were prepared. The tensile strength of UL‐10 fiber reached 1.2 GPa which would satisfy industrial applications demanding relative high mechanical properties. POLYM. ENG. SCI., 58:22–27, 2018. © 2017 Society of Plastics Engineers     

改性多壁碳纳米管／PA6纤维的制备及力学性能

将多壁碳纳米管(MWNT)氧化后,酰氯化处理,在氨基封端的PA6聚合时加入,制备PA6／MWNT母粒,将母粒同PA6切片熔融共混纺丝,制备PA6／MWNT纤维。用INSTRON 1122型万能材料试验机测定纤维的力学性能。结果表明,改性MWNT的加入提高了PA6纤维的断裂强度,纤维中MWNT质量分数仅为0．05％时,纤维的断裂强度和初始模量最大,分别增加了60％和86％。用扫描电镜观察复合纤维的结构,发现MWNT均匀地分布在PA6中,并与PA6基体间有相互作用,沿纤维轴向取向。     

Investigation of radiation-crosslinked foam of LDPE/EVA blends

Low-density polyethylene/ethylene–vinyl acetate copolymer (LDPE/EVA) blend was irradiated by γ-ray and then expanded by heat as a foamed material. The EVA content in the LDPE/EVA blend was benefited to form a gel. The gel fraction values of LDPE/EVA blend with 30% EVA content were higher than those of other blends in a same given dose; its gel fraction value was 1.7 times as those values of the LDPE without EVA. The gel fractions of the LDPE/EVA blend were increased with radiation dose in oxygen, in air, and in nitrogen, and the formation of gel was limited by oxygen. The oxidation products of the foam of the LDPE/EVA blend were observed in nitrogen, in oxygen by Fourier transform IR spectra. The LDPE/EVA blend system has no protection effect from oxidation in comparison with the LDPE system without EVA, which has less oxidation product than those without EVA in a same given gel fraction. The gel fraction of the LDPE/EVA blend around 25–35%, radiation dose 25±5 kGy, irradiated by γ-ray in air or in nitrogen, with higher expansion ratio (19), smaller cell diameter (0.175 mm), lower apparent density (0.042 g/cm³), higher tensile strength (0.40 MPa), and longer elongation at break (290–360%) foam of the LDPE/EVA blend were selected. These were optimum condition for application in this system. The relations among gel fraction of the LDPE/EVA blend, expansion ratio, apparent density, average cell diameter, and mechanical properties of the foam were discussed. © 1996 John Wiley & Sons, Inc.