A kind of preparation method of carbon nano tube reinforced polyvinyl alcohol composite fibre
Technical field
The present invention relates to a kind of preparation method of carbon nano tube reinforced polyvinyl alcohol composite fibre, particularly a kind of method that adopts dry-wet spinning prepared carbon nano tube reinforced polyvinyl alcohol composite fibre belongs to the reinforcing fiber materials preparing technical field.
Background technology
Polyvinyl alcohol (PVA) is a kind of water-soluble polymer that is formed by the polyvinyl acetate hydrolysis, and good chemical stability and biocompatibility are arranged, avirulence, and good spinnability.CNT has performances such as high-strength and high-modulus, high draw ratio, electrical property excellence, is widely used in reinforcing material at polymeric material field at present.
The emphasis of the polymer-base carbon nanotube composite that processability is good is that CNT is uniformly dispersed in polymeric matrix, can be by modified carbon nano-tubes such as the whole bag of tricks such as chloroazotic acid, DBSA, DNA, to improve its dispersiveness in polymer.Chinese invention patent " in a kind of method of dispersing nanometer pipe (CN101049926), disclose a kind of method that adopts the freeze-drying dispersing Nano carbon tubes, but this dispersion process complexity is difficult for suitability for industrialized production.After CNT disperses to obtain preliminary effect, the researcher will join the good composite of processability in the polymer again after its modification, Chinese invention patent " a kind of carbon nano-tube/nylon fibre modification epoxy resin composite material " (CN201210092656) in, it is strong to have prepared pliability, the composite that heat resistance and thermal conductivity are all good.In the Chinese invention patent " carbon nano tube/polyamide 6 amine 6 composite nano fiber filament yarns and preparation method thereof ", nano fiber filament yarn has excellent mechanical property.Chinese invention patent " a kind of carbon nano tube reinforced polyvinyl alcohol composite material and preparation method thereof " (CN1900155) in, with the polyvinyl alcohol is matrix, with the aqueous solution as dispersant, the CNT that cholate is modified is dispersed in the polyvinyl alcohol, with the mechanical property of raising polyvinyl alcohol composite material, but CNT is dispersed undesirable.
Summary of the invention
The objective of the invention is to overcome the deficiency that prior art exists, provide a kind of and can effectively improve the dispersiveness of CNT in polyvinyl alcohol, preparation has the good mechanical performance, and the method for the simple carbon nano tube reinforced polyvinyl alcohol composite fibre of production technology.
To achieve the above object of the invention, the technical solution adopted in the present invention provides a kind of preparation method of carbon nano tube reinforced polyvinyl alcohol composite fibre, comprises the steps:
(1) the dispersant Tea Polyphenols is dissolved in the solvent of methyl-sulfoxide and deionized water, adds multi-walled carbon nano-tubes again and carry out ultrasonic dispersion treatment, obtain multi-walled carbon nano-tubes/Tea Polyphenols system; Press mass ratio, Tea Polyphenols: multi-walled carbon nano-tubes is 2~5:1; By volume, methyl-sulfoxide: deionized water is 1~5:1;
(2) polyvinyl alcohol is dissolved in the solvent of methyl-sulfoxide and deionized water, adds multi-walled carbon nano-tubes/Tea Polyphenols system that step (1) prepares again, obtain polyvinyl alcohol spin dope after fully stirring; The concentration of described spinning solution is 12~16wt%, and wherein, the concentration of CNT is 0.4 * 10
-3~1 * 10
-3G/ml;
(3) adopt dry-wet spinning technology, controlling former liquid temp is 55~95 ℃, distance between spinning head and the coagulating bath is 0.5~1cm, coagulation bath temperature is-20~-30 ℃, winding speed is 20~40m/min, obtain a kind of carbon nano tube reinforced polyvinyl alcohol as-spun fibre, after solidifying again, cleaning, at room temperature leave standstill;
(4) obtain a kind of carbon nano tube reinforced polyvinyl alcohol composite fibre after the drawn PROCESS FOR TREATMENT.
The preparation method of carbon nano tube reinforced polyvinyl alcohol composite fibre provided by the invention, described coagulating bath, by volume, ethanol or methyl alcohol: water is 3~5:1.Described drawing process is a step drawing, and its process conditions are: phase I, 140~160 ℃ of draft temperatures, 2~4 times of draw ratios; Second stage, 180~200 ℃ of draft temperatures, 3~5 times of draw ratios.
Compared with prior art, the present invention has following tangible advantage:
1, the present invention adopts the interpolation CNT/method of Tea Polyphenols dispersion in poly-vinyl alcohol solution, adopt dry-wet spinning technology, polyvinyl alcohol/CNT system is made the enhancing composite fibre, the matrix polyvinyl alcohol has good fibre forming property, chemical stability and biocompatibility, avirulence etc., the good mechanical performance of its fiber;
2, to select Tea Polyphenols for use be surface dispersant in the present invention, this dispersant cost is low, obtain easily, environmentally friendly, nontoxic, nonirritant have excellent medical value, and dispersion process is simple, the time short, dispersion effect is good, and the fiber of preparation not only has industrial application value and also has potential medical value;
3, CNT has high TENSILE STRENGTH and modulus, big draw ratio, technical solution of the present invention employing CNT/tea polyphenols complex lies in the method in the poly-vinyl alcohol solution, can reach the purpose of the mechanical property height that changes fiber by the addition of controlling carbon nanotube, simple to operate, the composite fibre stable performance of preparing has excellent mechanical property;
4, technical scheme provided by the invention need not the process conditions of dangerous very complicateds such as strong acid backflow in the process of dispersing Nano carbon tubes, dispersion process is simple, can shorten the production time, reduces cost.
Description of drawings
Fig. 1 is the deployment conditions contrast photo of CNT in different solutions that the embodiment of the invention 1 provides;
Fig. 2 is the transmission electron microscope comparison diagram of the different system spinning solutions that provide of the embodiment of the invention 1;
Fig. 3 is the ESEM comparison diagram of the different fibers that provide of the embodiment of the invention 1.
The specific embodiment
Below in conjunction with drawings and Examples the present invention is further described.
Embodiment 1:
Methyl-sulfoxide/the aqueous solution that with the volume ratio is 3:1 is solvent.
The 44.5mg Tea Polyphenols is joined in the above-mentioned solvent of 10ml, magnetic agitation 10 minutes adds the 14.8mg multi-walled carbon nano-tubes again, and ultrasonic 30 minutes, place after one day, obtain finely disseminated CNT/Tea Polyphenols solution.
Take by weighing the 15.24g polyvinyl alcohol in two mouthfuls of flasks of drying, add the 80ml solvent, and add above-mentioned finely disseminated CNT/Tea Polyphenols solution, stirred 4 hours down for 90 ℃ at no magnetic field condition, polyvinyl alcohol/CNT/Tea Polyphenols the solution that makes solid content 16wt% is spinning solution, and wherein the content of CNT is 4 * 10
-3G/mL.
Preparation carbon nano-tube solution Comparative Examples: the 14.8mg multi-walled carbon nano-tubes is joined in the 10ml solvent, under the 45kHz frequency condition ultrasonic 30 minutes, leave standstill after one day and obtain a kind of carbon nano-tube solution.Press the same terms, polyvinyl alcohol is joined in the carbon nano-tube solution, make the Comparative Examples spinning solution.
Referring to accompanying drawing 1, it is the deployment conditions contrast photo of CNT in different solutions that present embodiment provides, (a) figure is the Comparative Examples carbon nano-tube solution, (b) figure is CNT/Tea Polyphenols solution, (c) figure is polyvinyl alcohol/CNT/Tea Polyphenols solution, by the contrast photo as can be seen, CNT reaches good dispersion in the mixed solution of polyvinyl alcohol and Tea Polyphenols at Tea Polyphenols solution.
Referring to accompanying drawing 2, it is the transmission electron microscope comparison diagram of the different system spinning solutions that provide of present embodiment; (a) figure is Comparative Examples polyvinyl alcohol/CNT system spinning solution, and (b) figure is polyvinyl alcohol/CNT/Tea Polyphenols system spinning solution; Can prove further that by transmission electron micrograph CNT is uniformly dispersed in Tea Polyphenols solution, not reunite.
Finely disseminated polyvinyl alcohol/CNT/Tea Polyphenols the solution that obtains is joined in the spin duct, the control temperature is 80 ℃, coagulation bath temperature is-30 ℃, coagulation bath composition is for by volume, methyl alcohol: water is 4:1, distance between spinneret orifice and coagulating bath is 1cm, and winding speed is 30m/min, obtains the carbon nano tube reinforced polyvinyl alcohol as-spun fibre.The fiber that will solidify and clean is placed at normal temperatures after one day and is stretched on xeothermic stretching-machine, and first section draft temperature is controlled at 150 ℃, stretches 2 times, and 200 ℃ of second section temperature stretch 4.5 times.Drawn strength test, gained fibre strength are 643MPa,
Adopt the same process condition to carry out spinning and stretching present embodiment Comparative Examples polyvinyl alcohol/CNT system spinning solution, obtain pure PVA fiber Comparative Examples, its intensity is 247MPa.,
Referring to accompanying drawing 3, it is the ESEM comparison diagram of the different fibers that provide of present embodiment; (a) figure is the pure vinal of Comparative Examples, (b) figure is the carbon nano tube reinforced polyvinyl alcohol composite fibre, can see by Fig. 3, the surface of polyvinyl alcohol/carbon nano tube composite fibre is the same very smooth with Comparative Examples vinal surface, not because the adding of CNT has destroyed the pattern of composite fibre.
Embodiment 2:
Take by weighing the 15.24g polyvinyl alcohol in two mouthfuls of flasks of drying, add the 80ml solvent, and the finely disseminated CNT/Tea Polyphenols solution of preparation among the adding embodiment 1, stirred 4 hours down for 90 ℃ at no magnetic field condition, make CNT and the poly-vinyl alcohol solution of solid content 14wt%, wherein the content of CNT is 2 * 10
-3G/mL.
Finely disseminated polyvinyl alcohol/CNT/Tea Polyphenols solution is added in the spin duct, the control temperature is 60 ℃, coagulation bath temperature is-20 ℃, coagulation bath composition is for by volume, methyl alcohol: water is 5:1, between spinneret orifice and coagulating bath apart from 0.6cm, winding speed 40m/min obtains the carbon nano tube reinforced polyvinyl alcohol as-spun fibre.
The fiber that will solidify and clean is placed at normal temperatures after one day and is stretched on the xeothermic again stretching-machine, and first section draft temperature is controlled at 140 ℃, stretches 2 times, and 190 ℃ of second section temperature stretch 3.5 times.The drawn strength test, the gained fibre strength is 480MPa, pure PVA fibre strength is 252MPa under the same terms.