碳纳米管-炭黑协同改性PTT/PET复合纤维的制备及导电性能

聚对苯二甲酸丙二醇酯/聚对苯二甲酸乙二醇酯(PTT/PET)复合纤维具有稳定且高度螺旋的卷曲结构,为改善其抗静电性能,采用碳纳米管(CNT)/炭黑(CB)复合填料对PTT进行共混改性。将不同质量比的CNT,CB及PTT共混挤出,制备出用于纺丝的CNT/CB/PTT共混切片,CNT/CB/PTT共混切片与PET切片复合纺丝制备CNT-CB协同改性PTT/PET复合纤维,并对复合纤维的导电性能进行表征。结果表明:采用质量分数1%的CNT和质量分数10%的CB作为导电填料对PTT改性,导电粒子在PTT基体中未出现明显的团聚,且CNT和CB可以形成较为完善的复合导电通路,制备的CNT/CB/PTT共混切片可用于纺丝;将CNT/CB/PTT共混切片与PET切片按质量比50∶50进行复合纺丝,制得的复合纤维具有良好的导电性能;随拉伸倍数的提高,复合纤维的体积电阻率呈下降趋势,但拉伸倍数过高,会损坏CB与CNT在PTT基体中形成的导电网络,当拉伸倍数为3. 3时,未改性的PTT/PET复合纤维体积电阻率为3. 58×10~9Ω·cm,而改性复合纤维的体积电阻率下降至5. 44×10~6Ω·cm。     

聚酯/碳纳米管导电纤维结构与性能的研究

通过双螺杆挤出机制备聚酯／碳纳米管(PET／CNTs)导电复合材料,为保证CNTs在PET中分散均匀,同时加入了矿物偶联剂,经扫描电镜分析,加入相对CNTs质量分数为50％矿物偶联剂能帮助CNTs在PET基体中均匀分散。PET复合材料中加入质量分数约为2％的CNTs可以使其体积电阻率从1014下降到102数量级。采用复合纺丝获得了导电纤维,分别在PET织物和羊毛织物中,添加相对织物质量分数为25％,3％的PET／CNTs导电纤维,可使相应织物具有优良的抗静电效果。     

拉伸工艺对PET/PTT复合纤维性能的影响

以310 dtex/48 f聚对苯二甲酸乙二醇酯(PET)/聚对苯二甲酸丙二醇酯(PTT)复合预向丝为原料,经拉伸后得到PET/PTT复合纤维,探讨了拉伸工艺对PET/PTT复合纤维力学性能和卷曲性能的影响。结果表明:在卷绕速度为500 m/min,拉伸温度160℃,热定型温度150℃的条件下,随着拉伸倍数的增加,PET/PTT复合纤维的断裂强度、沸水收缩率、卷曲收缩率明显提高,断裂伸长率呈下降趋势,卷曲稳定度变化不明显;拉伸温度和热定型温度对PET/PTT复合纤维力学性能和卷曲性能的影响相对较小;拉伸过程中,控制拉伸倍数为1.95～2.00,拉伸温度为140～160℃,热定型温度为130～170℃,PET/PTT复合纤维性能较好。     

多壁碳纳米管增强PET纤维的初步研究

选择体积含量为70%的三氟乙酸(TFA)与30%二氯甲烷(DCM)作为混合溶剂,采用溶液法可制得用于增强聚对苯二甲酸乙二酯(PET)纤维的PET/多壁碳纳米管(MWCT)混合母粒。扫描电镜(SEM)观察发现MWCT在母粒内分散良好。将PET/MWCT母粒与纯PET切片熔融纺丝,制备出了力学性能明显增强的纤维。在实验的最佳纺丝条件下,MWCT质量含量为0.04%时,纤维断裂强度可达到5.25cN/dtex、初始模量达到119.7cN/dtex,分别比相同条件下的纯PET纤维提高21.0%和37.6%。     

大直径PTT/PET皮芯型复合纤维的性能研究

采用一定比例的聚对苯二甲酸乙二醇酯(PET)和聚对苯二甲酸丙二醇酯(PTT)进行复合纺丝纺制以PTT为皮,PET为芯的大直径PTT/PET皮芯型复合纤维,研究了熔体温度、冷却水温度、复合比对PTT/PET复合纤维力学性能和弹性回复性能的影响。结果表明:较佳的PTT和PET的熔体温度分别为265℃和285℃,冷却水温度为50～60℃,PTT/PET质量比为50/50;随着PTT含量增加,PTT/PET复合纤维的断裂强度降低,断裂伸长率增加,弹性回复率增大。     

PET/碳纳米管复合材料的结晶性能和力学性能研究

采用熔融共混法制备了聚对苯二甲酸乙二醇酯/碳纳米管(PET/CNT)复合材料。研究了CNT用量对PET/CNT复合材料结晶性能和力学性能的影响。结果表明:CNT对PET基体具有明显的异相成核作用,显著提高了PET的熔融温度和相对结晶度;PET/CNT复合材料的断裂强度和屈服强度随着CNT用量的增加先提高后降低,在CNT用量为1%时达到最大值;PET/CNT复合材料的断裂伸长率随着CNT用量的增加呈先降低后提高的趋势;随着CNT用量的增加,PET/CNT复合材料的弯曲强度和弯曲模量呈先增大后减小的趋势;而复合材料的冲击强度随着CNT用量的增加先减小后增大。     

PET/PTT复合纤维卷缩性能的研究

通过对不同线密度的聚对苯二甲酸乙二醇酯/聚对苯二甲酸丙二醇酯(PET/PTT)复合纤维的热收缩率、卷曲收缩率、卷曲模量及卷曲稳定度的测试,研究了干热和沸水处理条件下的PET/PTT复合纤维的卷缩性能。结果表明:干热处理时,PET/PTT复合纤维的热收缩率随温度的升高而升高,随线密度的提高而减小;与干热处理比较,沸水加压处理后的纤维具有较好的热收缩率和卷曲性能。PET/PTT复合纤维线密度越低,其卷曲收缩能力越强,线密度为172 dtex时,纤维表现出较好的卷曲收缩率和卷曲稳定性。     

纺丝工艺对PET/PTT复合纤维性能的影响

将不同黏度的聚对苯二甲酸乙二醇酯(PET)与聚对苯二甲酸丙二醇酯(PTT)按质量比40∶60进行混合,通过熔融复合纺丝、拉伸制得PET/PTT复合纤维,研究了纺丝工艺对纤维力学性能以及卷曲弹性的影响。结果表明:随着PET与PTT的特性黏数差由0.12 d L/g增加至0.54 d L/g,PET/PTT复合纤维的断裂强度和初始模量下降,断裂伸长率增加;随着拉伸比由2.5增加至4.5以及拉伸辊温度由120℃升高至150℃,PET/PTT复合纤维的断裂强度增加,断裂伸长率降低,卷曲性能增加,弹性增大。     

热处理对PET/PTT复合纤维力学性能的影响

对不同线密度的聚对苯二甲酸乙二醇酯/聚对苯二甲酸丙二醇酯(PET/PTT)复合纤维分别进行干热处理,常压沸水处理,120℃及0.2MPa的高压沸水处理,研究了其热处理前后的力学性能。结果表明:PET/PTT复合纤维经常压沸水处理后,初始模量下降,断裂伸长率及断裂功增大,断裂强度略有减小;复合纤维经高压沸水处理后,其力学性能明显提高,常压沸水处理其次,干热处理则变化不大;复合纤维经干热处理后,其初始模量、断裂强度、断裂伸长率及断裂功随温度的升高均先升高后降低,150℃时达到最大。     

PET/PTT共混纤维的制备及结构性能研究

将聚对苯二甲酸乙二酯(PET)与聚对苯二甲酸丙二醇酯(PTT)共混纺丝制备PET/PTT共混纤维,研究了共混纤维的结构与性能。结果表明,随着PTT含量的增加,PET/PTT共混纤维的晶粒尺寸逐渐增大;PET/PTT共混纤维的断裂强度较PTT纤维大,回弹性较PET纤维好,沸水收缩率较PET纤维大;当PTT质量分数为50%时,共混纤维的结晶度出现最小值,沸水收缩率出现最大值。     

Preparation and properties of multi-walled carbon nanotube/carbon/polystyrene composites

Multi-walled carbon nanotube (MWCNT)/C/polystyrene (PS) composite materials were prepared by in situ polymerization of monomer in preformed MWCNT/C foams. MWCNT/C foams were preformed using polyurethane foam as template. The preformed MWCNT/C foams had a more continuous conductive structure than the carbon nanotube networks formed by free assembly in composites. The structure of the MWCNT/C foam network was characterized with scanning electron microscopy. The MWCNT/C/PS composites have an electric conductivity higher than 0.01 S/cm for a filler loading of 1 wt.%. Enhancement of thermal conductivity and mechanical properties by the preformed MWCNT/C foam were also observed.     

聚乙烯醇/磺酸化碳纳米管复合纤维的制备与性能研究

采用湿法纺丝法制备了聚乙烯醇/磺酸化多壁碳纳米管(PVA/s-MWCNTs)复合纤维,并对复合纤维的结构与性能进行了表征。结果表明:当纤维中s-MWCNTs质量分数为5%时,s-MWCNTs均匀地分散在PVA基体中,当s-MWCNTs质量分数增加到8%时,纤维中出现少许s-MWCNTs团聚体;随着s-MWCNTs含量的增加,复合纤维的结晶度逐渐降低,PVA微晶取向度先增大后减小,纤维的模量和断裂强度均先增大后减小,电导率逐渐增加;当s-MWCNTs质量分数为5%时,纤维力学性能较好,其断裂强度和模量分别为0.83GPa和15 GPa,而s-MWCNTs质量分数为8%时,纤维电学性能较好,其电导率为0.65 S/m。     

Preparation and properties of biodegradable PBS/multi-walled carbon nanotube nanocomposites

In this study, poly(butylene succinate)/multi-walled carbon nanotube (PBS/MWNT) hybrids were prepared by a melt-blending process. The carbon nanotubes (CNTs) were successfully modified using N,N′-dicyclohexylcarbodiimide (DCC) dehydrating agents. As a result, excellent dispersion of the modified carbon nanotubes (CNT-C18) in organic solvents was achieved. Subsequently, the PBS/CNT nanocomposites were prepared through facile melt blending. Mechanical properties, thermal behavior, conductivity of these resultant polymer/CNT composites were investigated. The results obtained show that the PBS/CNT-C18 nanocomposites consisting of well-dispersed nanotubes exhibited enhanced thermal and mechanical properties. With the addition of 3 wt% CNT-C18, T_d of the nanocomposite increased 12.3 °C as compared to that of the pristine PBS sample. Moreover, the increments of E′ and E″ of the nanocomposite at 25 °C were 120 and 55%, respectively. In the aspect of conductivity, the surface resistivity of the PBS/CNT-C18 composite was found to be 7.30 × 10⁶ Ω, which is a decrease of 10⁹ fold in value as compared to that of the pristine PBS sample. Such PBS/CNT-C18 sample exhibits high anti-static efficiency, which would be potentially useful in electronic packaging materials.     

碳纳米管/聚丙烯腈复合纤维的制备及结构研究

通过原位聚合的方法制备了碳纳米管/聚丙烯腈(CNTs/PAN)聚合液,用湿法纺丝工艺制备了CNTs/PAN复合纤维,分析了复合纤维流变性能、热性能及截面形貌。结果表明:CNTs的加入使得聚合物溶液出现了假凝胶化,粘度和弹性均有所上升,纺丝时溶液细流的表层遇水迅速凝固成致密的皮层,影响了纤维芯部的二甲基亚砜(DMSO)和水的双扩散作用,凝固丝出现了很明显的皮芯结构,CNTs的加入还使得纤维预氧化放热过程得到了缓和。     

Preparation and properties of graphene/multi-walled carbon nanotube/thermoplastic vulcanizate composites

通过熔融接枝共混制备了石墨烯（Ge）/多壁碳纳米管（MWCNTs）/聚丙烯（PP）母粒,然后与丁基橡胶动态硫化制备了Ge/MWCNTs/热塑性硫化胶（TPV）复合材料,考察了Ge/MWCNTs/TPV复合材料的相态结构、热电性能和力学性能。结果表明,Ge/MWCNTs作为异相成核剂能够提高PP的结晶温度;Ge/MWCNTs/TPV复合材料呈现“海-岛”结构,Ge和MWCNTs在PP相和橡塑两相界面分散均匀、与基体结合能力强。加入质量分数均为3%的Ge和MWCNTs时,Ge/MWCNTs/TPV复合材料的直流电导率提高5个数量级,热导率提高了36.7%,拉伸强度达17.3 MPa,扯断伸长率达260%。     

The thermal and mechanical properties of a polyurethane/multi-walled carbon nanotube composite

A polyurethane/multi-walled carbon nanotube elastomer composite was synthesized. The microstructure of the composite was examined by field-emission scanning electron microscopy and transmission electron microscopy. The thermal and mechanical properties of the composite were characterized by dynamic mechanical thermal analysis, thermogravimetric analysis and tensile testing. The chemical linkage of carbon nanotubes with polyurethane matrix was confirmed by Fourier transform infrared spectra. The study on the structure of the composite showed that carbon nanotubes could be dispersed in the polymer matrix well apart from a few of clusters. The results from thermal analysis indicated that the glass transition temperature of the composite was increased by about 10 °C and its thermal stability was obviously improved, in comparison with pure polyurethane. The investigation on the mechanical properties showed that the modulus and tensile strength could be obviously increased by adding 2 wt% (by weight) CNT to the matrix.     

聚苯胺及其导电阻燃涤纶的制备

采用氧化聚合的方法合成聚苯胺,并考察了不同温度下聚苯胺的产率和电导率,探讨了阻燃涤纶碱减量处理条件,用原位聚合的方法制备聚苯胺/阻燃涤纶导电纤维。结果表明,在-20℃下合成的聚苯胺产率较高为84%,电导率为124 S/cm。阻燃涤纶碱减量处理的适宜条件为:温度80℃,碱浓度为5%,处理时间15-20 min,低温下制备的聚苯胺/阻燃涤纶失重为2.50%-5.25%时,纤维的电导率提高得较快,为0.07-0.13 S/cm。     

Mechanical properties of carbon nanotube/carbon fiber reinforced thermoplastic polymer composite

Carbon nanotube (CNT)/carbon fiber (CF) hybrid fiber was fabricated by sizing unsized CF tow with a sizing agent containing CNT. The hybrid fiber was used to reinforce a thermoplastic polymer to prepare multiscale composite. The mechanical properties of the multiscale composite were characterized. Compared with the base composite (traditional commercial CF), the multiscale composite reinforced by the CNT/CF hybrid fiber shows increases in interlaminar shear strength (ILSS) and impact toughness. Laminate containing CNTs showed a 115.4% increase in ILSS and 27.0% increase in impact toughness. The reinforcing mechanism was also discussed by observing the impact fracture morphology. POLYM. COMPOS., 38:2001–2008, 2017. © 2015 Society of Plastics Engineers