软硬链段添加碳纳米管/炭黑对聚氨酯纳米纤维性能的影响

Effects of carbon nanotubes/carbon black dispersed in soft and hard chain segments on properties of polyurethane nanofibers

摘要:

以聚丙二醇(PPG 2000)和二苯基甲烷二异氰酸酯(MDI-50)为原料，利用预聚法合成聚氨酯(PU)。在预聚过程中加入碳纳米管(CNT)，合成碳纳米管/聚氨酯(CNT/PU)；在扩链过程中加入炭黑(CB)，合成炭黑/聚氨酯(CB/PU)。结合静电纺丝，制备CNT/PU、CB/PU纳米纤维。采用SEM、TEM、FTIR、DSC、XRD、电性能、力学性能以及传感性能测试对两种纳米纤维的结构和性能进行了表征。结果表明，由于碳纳米管/炭黑在PU软硬链段的选择性嵌入，PU纳米纤维的微相分离程度增大/减小；CNT/PU纤维的断裂伸长率降低，CB/PU纤维的断裂强度提高。导电填料的含量以聚氨酯的质量（实验所用PPG 2000、MDI-50和无水乙二胺的总质量）为基准，当CNT的含量为6%时，CNT/PU纤维的电阻率为1.22 Ω•m，应变传感系数(GF)为45.64；当CB含量为12.5%时，CB/PU纤维的电阻率为0.14Ω•m，GF为167.43。

Abstract:

Polyurethane (PU) was synthesized from polypropylene glycol (PPG 2000) and diphenylmethane diisocyanate (MDI-50) by a prepolymerization method.The carbon nanotubes(CNT) were added in the prepolymerization process to synthesize carbon nanotubes / polyurethane (CNT / PU),while carbon black(CB) was added in the process of chain extension to synthesize carbon black / polyurethane (CB / PU).CNT/PU nanofibers and CB/PU nanofibers were obtained by eletrospinning technique.The structure and properties of the two kinds of nanofibers were characterized by SEM,TEM,FTIR,DSC,XRD , electrical,mechanical and sensing properties tests.The results showed that, because of the selective embedding of carbon nanotubes / carbon black in the soft and hard segments of PU,the degree of microphase separation of PU nanofibers increases / decreases;the elongation at break of CNT / PU fibers decreases, and the breaking strength of CB / PU fibers increases.The content of conductive filler is based on the mass of polyurethane (the total mass of PPG 2000, MDI-50 and anhydrous ethylenediamine used in the experiment)，when the CNT content is 6%, the resistivity of CNT / PU fibers was 1.22Ώ•m and the strain sensing coefficient (GF) was 45.64; when the CB content is 12.5%, the resistivity of CB / PU fibers was 0.14Ώ•m, GF was 167.43.