三维网状结构增强磁流变弹性体的研究

发布时间：2018-01-02 09:52

本文关键词：三维网状结构增强磁流变弹性体的研究　出处：《中国科学技术大学》2016年博士论文　论文类型：学位论文

【摘要】：磁流变弹性体(MRE)是将微米级的软磁性颗粒分散到具有黏弹性的高分子聚合物中复合而成的一种智能材料,对MRE施加可变磁场时,其力学性能随磁场强度变化发生连续、可逆的变化,因此可以被应用于减震、降噪、隔振等领域。通过对基体改性或对软磁性微米级颗粒进行修饰可以改善MRE的力学性能,改变模量及阻尼性能,因此目前MRE的主要研究对象是基体和颗粒分散相。作为一种新型智能复合材料,MRE结构设计没能引起足够的重视。MRE的经典结构是软磁性颗粒在基体内部定向排列成链状结构。这种结构虽然在MRE中广泛应用,但由于其链状结构在基体中缺乏支撑物,受到剪切作用的时候,容易被破坏。因此,为了使MRE具有理想的储能模量和磁流变效应,对MRE进行结构设计是十分必要和有意义的。本文以设计MRE的复合材料结构为目的,选择了三维网络骨架结构增强MRE,系统地研究了骨架结构对MRE性能的影响。利用松香甘油酯增强天然橡胶基体研究基体润湿性对磁流变性能的影响,选用聚氨酯海绵骨架,研究骨架对MRE内羰基铁粉的链状结构的限制作用,首次将碳纳米管和银纳米线覆载到聚氨酯海绵骨架上,研究了MRE电阻对应变和磁场的响应。该研究工作改善了MRE的力学性能,将MRE的应用范围拓展到传感器领域。具体内容如下：1、将松香甘油酯添加到天然橡胶基体中来增加基体对菝基铁粉的润湿性和羧基铁粉的分散性,增强了天然橡胶基体MRE的力学性能。在不同磁场、应变和频率条件下,研究了基体和羰基铁粉之间润湿程度对MRE力学性能的影响。与纯天然橡胶基体MRE相比,松香甘油酯/天然橡胶互穿网状结构对羰基铁粉有更好的润湿性能,因此能降低MRE的阻尼。松香甘油酯的添加还能增加MRE的磁致模量。本文研究了基体对羰基铁粉的润湿性和羰基铁粉的分散性对MRE力学性能的影响,对提高MRE力学性能有一定指导作用。2、将多孔海绵结构植入到磁流变塑性体中,制备出磁流变复合材料。重点研究三维骨架对磁流变复合材料内部铁粉的限制作用,发现三维骨架的植入能极大地提升磁致模量和磁流变效应。将具有弹性的多孔聚氨酯海绵骨架植入到磁流变塑性体中,制备出的MRE可以反复被拉伸和弯曲。研究发现,MRE内部的多孔骨架结构可以有效的分散对MRE施加的剪切力,能同时增大MRE的零场储能模量和磁致模量。而多孔骨架的植入对MRE的阻尼性能几乎没有影响。该方法为增加MRE的磁致模量、提高MRE的力学性能提供了可行性方案,对MRE在工程上的应用方面意义重大。3、对MRE内部三维网状结构展开了一系拓展研究。将多孔海绵骨架上分别覆载导电碳纳米管及银纳米线,系统研究了交联度、应变和磁场对MRE电阻性能的影响,发现MRE的电阻随应变和磁场变化均能产生相应变化。研究表明：柔性的碳纳米管对MRE的储能模量和磁致模量都有增强作用。覆载碳纳米管后MRE的导电性有极大提升,其电阻随应变变化而连续有规律的变化。该特殊性能可以将MRE的应用范围拓展到应变传感器领域。而银纳米线对MRE的储能模量和磁致模量都有降低作用,应综合考虑其力学性能和电学性能。但由于银纳米线导电性好,MRE的电阻变化随应变变化更加灵敏,且电阻能随磁场变化而变化。因此研究银纳米线对MRE导电性影响意义重大,可以将MRE用作磁场传感器。此外,本文还细致的研究了基体交联度对MRE电阻性能的影响。上述研究拓展了MRE在传感器领域的应用,具有十分重要的意义。
[Abstract]:Magnetorheological elastomer (MRE) is the dispersion of soft magnetic particles of micron to a kind of smart material compounded with viscoelastic polymer in a variable magnetic field on MRE, the mechanical properties change with the magnetic field strength of continuous, reversible changes, so it can be applied to vibration, noise, vibration etc. through modification of the matrix or modification can improve the mechanical properties of MRE soft magnetic particles, changing the modulus and damping properties, so the main research object is MRE matrix and dispersed phase particles. As a new type of intelligent composite materials, the structural design of MRE did not cause enough attention to the classic structure of.MRE the soft magnetic particles in the matrix of aligned chain structure. This structure is widely used in the MRE, but because of its lack of support chain structure in the matrix, when subjected to shear for the That is easy to be destroyed. Therefore, in order to make MRE with ideal storage modulus and magnetorheological effect, the structure design of MRE is very necessary and meaningful. This paper aims at the structure design of the composite material MRE, the three-dimensional network skeleton structure enhanced MRE, systematic study of the influence of skeleton structure on the performance of MRE the enhancement effect of matrix. The study of natural rubber matrix wettability on magnetic rheological properties of the rosin glyceride, using polyurethane sponge skeleton, limiting chain structure of MRE in the study of carbonyl iron skeleton, the carbon nanotubes and silver nanowires coated to the polyurethane foam skeleton, the response of the strain and resistance of MRE the magnetic field. The research work to improve the mechanical properties of MRE, extending the application of MRE to the sensor field. The specific contents are as follows: 1, the rosin glyceride is added to the natural rubber matrix to increase The dispersion matrix on the basis of iron and Smilax wettability and carboxyl iron powder, to enhance the mechanical properties of natural rubber matrix MRE. Under different magnetic field, strain and frequency conditions, studied the effect of wetting degree between matrix and carbonyl iron powder on the mechanical properties of MRE. Compared with the pure natural rubber matrix MRE, rosin glycerol ester natural rubber / interpenetrating network structure has better wetting properties of carbonyl iron powder, it can reduce MRE damping. Adding rosin glycerol ester can increase the magnetic modulus of MRE. This paper studies the influence of dispersion matrix on the wettability of carbonyl iron and carbonyl iron powder on the mechanical properties of MRE,.2 has a certain guiding role to improve the mechanical properties of MRE, the porous sponge structure into magnetorheological plastic body, preparation of magnetorheological composite materials. Focusing on the function of 3D limit skeleton on Magnetorheological composite materials of iron powder, three Dimensional skeleton implantation can greatly enhance the magnetic modulus and magnetorheological effect. The elastic porous polyurethane foam skeleton into magnetorheological plastic body, the prepared MRE can be repeated stretching and bending. The study found that porous structure of MRE can effectively disperse the internal shear force applied on MRE, modulus and magnetic modulus to zero field storage while increasing MRE. And the damping properties of porous implant of MRE has almost no effect. The method to increase the magnetic modulus of MRE, provides a feasible solution to improve the mechanical properties of MRE, the application of MRE to engineering significance in.3, launched a research and development a series of MRE internal three-dimensional network structure. The porous sponge skeleton respectively with carrying conductive carbon nanotubes and silver nanowires, studied crosslinking degree and the effect of strain and magnetic field on MRE resistance performance, with resistance MRE The strain and magnetic field changes can produce corresponding changes. The study shows that the flexibility of carbon nanotubes on the storage modulus of MRE and magnetic modulus are enhancement. The load of carbon nanotubes after the conductivity of MRE has greatly improved, and the resistance strain changes with continuous rule change. The special properties can be applied the MRE is extended to the strain sensor field. And the silver nanowires on the storage modulus of MRE and magnetic modulus decreased, should be considered for the mechanical and electrical properties. But because the silver nanowires with good conductivity and resistance change of MRE strain is more sensitive, and the resistance can change with the change of magnetic field. So the study of silver nanowires is significant influence on the conductivity of MRE, MRE can be used as a magnetic field sensor. In addition, this paper also studied effect of matrix crosslinking degree on MRE resistance performance. The study extends the MRE in sensing The application of the device field is of great significance.

【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：O37;TB381

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