基于水浴静电纺的芳纶/PA6纳米纤维包芯纱制备与表征

Preparation and characterization of PPTA/PA6 nanofiber core-spun yarn basedon water bath electrospinning

针对单一纳米纤维纱力学性能较差、进一步后加工困难、应用受限等问题,本文采用静电纺丝法在水浴表面收集纳米纤维,制备以芳纶1414(PPTA)长丝为芯层、聚酰胺6(PA6)纳米纤维为皮层的PPTA/PA6纳米纤维包芯纱,并分析了纳米纤维包芯纱和外层纳米纤维包覆层的结构与性能。结果表明:纳米纤维均匀地包覆在芯纱外层,纳米纤维的直径范围主要分布在90~110 nm,平均直径为98.81 nm;纳米纤维包覆层的熔点为223.16℃,结晶度为18.55%,与常规PA6纤维接近;纳米纤维包芯纱的力学性能与芯纱接近,且纳米纤维包覆层也具备一定的力学性能,平均强度为0.57 cN/dtex,平均伸长率为33.30%;纳米纤维包覆层具有一定的耐摩性,经棉织物摩擦600次后其形态结构基本未发生变化。

With the in-depth studies on nanofiber technology,nanomaterials play an important role in more and more fields.Electrospinning technology,as one of the main methods of nanofiber preparation,can produce nanofibers through electrification and drawing by applying high voltage to the polymer melt or solution.It has the advantages of simple process,convenient operation and fast manufacturing speed.However,in the process of electrospinning,due to the extremely fast speed of the medium polymer jet and the unstable whip in the high-voltage electric field,the morphology and movement state of the nanofiber receiving device will affect the structure of nanofiber aggregates.Although conventional static receivers can collect random and disorderly arranged nanofiber films,the films with low strength can hardly be used for further textile processing,limiting its application and development.By preparing one-dimensional nanofiber tows or nanofiber yarns through the improvement of the receiving device,the strength of nanofiber aggregates can be effectively enhanced.However,due to the low crystallinity of nanofibers and low orientation along the length of the yarn,compared with traditionalyarns,there is still a certain gap in the mechanical properties of such yarns entirely composed of nanofibers.Therefore,the preparation of nanofiber aggregates which have surface properties of nanofibers and maintain excellent mechanical properties of traditional fibers is beneficial to expand the application field of nanofibers and improve the application value.Preparing nanofiber core-spun yarns with traditional yarn as the core and nanofibers coating on the surface of the core yarn is a simple and feasible method to achieve the above goals,which has been extensively studied.At present,mechanical bundling method,water bath method and air-assisted method are common preparation methods of nanofiber core-spun yarns.Among them,in the process of preparing nanofiber core-spun yarns by the mechanical bundling method and the air-assisted method,due to the unstable jet of nanofibers,they cannot be completely coated on the surface of the core yarn,resulting in low utilization rate of nanofibers and affecting the yield.By using water bath method,all the nanofibers deposited on the surface of water can be coated on the core yarn,greatly enhancing the utilization rate of nanofibers.On this basis,PPTA/PA6 nanofiber core-spun yarn was prepared via a self-developed water bath electrospinning method in this article,with aramide 1414(PPTA)filament as the core layer and polyamide 6(PA6)nanofiber as the cortex.The structure and properties of the nanofiber core-spun yarn were studied.The results indicated that the nanofibers were evenly coated in the outer layer of the core yarn without exposing the core and hairiness.The diameter of the nanofibers mainly ranged from 90 nm to 110 nm,with an average diameter of 98.81 nm.The thickness of nanofiber coating was about 25μm,and the structure was complete and uniform.The melting point of the nanofiber coating was 223.16℃,and the crystallinity was 18.55%,similar with those of conventionally prepared PA6 fibers.The strength of nanofiber coating was 0.57 cN/dtex,lower than the conventional PA6 fiber,but the elongation of 33.30%and the modulus of 2.15 cN/dtex were both within the range of conventional PA6 fibers,indicating that the nanofiber core-spun yarn has the characteristics of nanofibers and mechanical properties of core yarn.The nanofiber coating has certain wear resistance without changes in its surface morphology and structure after being rubbed by cotton fabric for 600 times.The nanofiber core-spun yarn prepared by the water bath electrospinning technology not only enables traditional yarns to obtain a larger specific surface area but also enhances the mechanical properties of nanofibers,thus expanding nanofiber application to the biological scaffold,flexible sensor,electronic devices,fuel cell and other fields.Especially,with the continuous development of smart textiles,nanofiber core-spun yarn as a flexible sensor can effectively and quickly transmit external information and respond,thereby obtaining more wide application.