發(fā)布時間：2018-04-01 04:21

  本文選題：導電橡膠　切入點：力敏效應　出處：《昆明理工大學》2015年碩士論文

【摘要】：導電橡膠屬于導電高分子復合材料,是將導電填料均勻分散在高分子彈性體基體內(nèi),使其同時具有彈性和導電性的一種新型半導體功能材料。導電橡膠具有較好的力敏和溫敏等性能,因此適合用于制備柔性觸覺傳感器的力敏器件和溫敏器件。影響導電橡膠的力敏效應和溫敏效應的因素很多,力敏機理與溫敏機理雖然都是基于導電橡膠的導電機理,但其實質(zhì)卻不一樣。本文闡述了導電高分子復合材料的導電機理；分析了基于導電通路理論和量子隧道效應理論的力敏機理和溫敏機理；總結(jié)歸納了具有代表性的力敏和溫敏數(shù)學計算模型；提出了新的導電硅橡膠制備工藝,為后續(xù)的實驗研究打好基礎；分別研究了橡膠基體材料的粘度以及組分、硫化劑、炭黑填充量以及改性材料添加劑等因素對導電硅橡膠的力敏效應和溫敏效應的影響。本文分別從導電橡膠力敏效應和溫敏效應兩個方面進行了研究。提出了可以消除填料團聚結(jié)塊并提高填料分散性的處理方法和利用硅烷偶聯(lián)劑對填料粉末進行改性的新方式。確定了導電硅橡膠脫模后固化成型所需要的時間為12小時左右。提出了新的導電硅橡膠制備工藝,細化并且量化了制備導電硅橡膠原材料添加順序、攪拌速度以及攪拌時間等制備參數(shù),提高了導電填料的分散性,降低了滲流閾值(從6%下降到4%)。研究了基體材料的粘度以及組分、硫化劑、改性材料添加劑對導電硅橡膠的壓阻特性、弛豫特性以及遲滯特性等力敏性能的影響。發(fā)現(xiàn)：(1)硅橡膠基體的粘度(在1500-10000 mPa.s范圍內(nèi))越高,壓阻特性越好,電阻弛豫時間越短,電阻遲滯特性系數(shù)越��；(2)雙組分基體比單組分基體壓阻特性曲線的光滑度好,電阻弛豫時間短,電阻遲滯特性系數(shù)��；(3)硅烷偶聯(lián)劑可以作為硫化劑單獨使用；(4)硅烷偶聯(lián)劑Si-69與正硅酸乙酯并用作為硫化劑時,硫化時間短,壓力敏感區(qū)間較大,壓阻范圍較大,電阻弛豫時間較短,且壓阻曲線的規(guī)律性較好,導電硅橡膠的力敏效應較好；(5)提高硫化溫度,能加快硫化速率,但對導電硅橡膠的內(nèi)部結(jié)構產(chǎn)生不良影響,影響復合材料體系的穩(wěn)定性；(6)添加多壁碳納米管改性材料能顯著增大導電硅橡膠的壓阻范圍,減小電阻弛豫時間,具有良好的力敏效應,在0-50N壓力范圍內(nèi)可以作為柔性力敏傳感器的力敏元件使用。研究了不同乙炔炭黑填充量對室溫硫化導電橡膠溫敏效應的影響。發(fā)現(xiàn)在滲流區(qū)間4%-12%范圍內(nèi),當導電填料填充量較少,靠近4%滲流閾值時,導電橡膠呈現(xiàn)正溫度系數(shù)效應；當導電填料填充量進一步增大,達到8%,處于高電阻區(qū)與導電區(qū)之間時,導電橡膠先呈現(xiàn)正溫度系數(shù)效應,后呈現(xiàn)負溫度系數(shù)效應,存在溫度臨界點80℃；當導電填料填充量較大,靠近導電區(qū)時,導電橡膠呈現(xiàn)負溫度系數(shù)效應。導電乙炔炭黑填充量為4%的導電硅橡膠在20℃-120℃范圍內(nèi)具有良好的溫敏效應,適合作為柔性溫敏傳感器的敏感器件。對于同一種室溫硫化硅橡膠基體(粘度在1500-10000 mPa.s范圍內(nèi)),其粘度越小,導電橡膠表現(xiàn)出負溫度系數(shù)效應越明顯。在炭黑填充量為10%時,單組分制備得到的導電硅橡膠先呈現(xiàn)負溫度系數(shù)效應,后呈現(xiàn)正溫度系數(shù)效應；而雙組分制備得到的導電硅橡膠的表現(xiàn)出一致性的負溫度系數(shù)效應。
[Abstract]:The conductive rubber belongs to a conductive polymer composite material , which is a novel semiconductor functional material which uniformly disperses the conductive filler in the polymer elastomer matrix so as to simultaneously have elasticity and electrical conductivity .
The mechanism of force - sensitive mechanism and temperature - sensitive mechanism based on the theory of conductive path and quantum tunneling effect are analyzed .
In this paper , a representative force - sensitive and temperature - sensitive mathematical model is summarized .
The preparation technology of new conductive silicone rubber is proposed , which provides a good basis for the subsequent experimental research .
The effects of the viscosity and the components , vulcanizing agent , carbon black filling amount and the additive of modified materials on the force - sensitive and temperature - sensitive properties of the conductive silicone rubber were studied .
( 2 ) the two - component matrix is better than the single - component substrate pressure resistance characteristic curve , the resistance relaxation time is short , and the resistance hysteresis characteristic coefficient is small ;
( 3 ) the silane coupling agent can be used as a vulcanizing agent alone ;
( 4 ) When the silane coupling agent Si - 69 and ethyl orthosilicate are used as the vulcanizing agent , the vulcanizing time is short , the pressure sensitive interval is large , the pressure resistance range is large , the resistance relaxation time is short , and the regularity of the piezoresistive curve is good , and the force sensitivity effect of the conductive silicone rubber is good ;
( 5 ) the vulcanization temperature can be increased , the vulcanization rate can be accelerated , the internal structure of the conductive silicon rubber is adversely affected , and the stability of the composite material system is influenced ;
( 6 ) Adding multi - wall carbon nanotube modified material can significantly increase the piezoresistive range of conductive silicone rubber , reduce the relaxation time of resistance , and can be used as a force sensitive element of flexible force sensitive sensor in the range of 0 - 50N . It is found that the conductive rubber exhibits positive temperature coefficient effect in the range of 4 % -12 % of percolation range , when the filling amount of conductive filler is less , and near 4 % percolation threshold .
when the filling quantity of the conductive filler is further increased to reach 8 percent , the conductive rubber firstly presents a positive temperature coefficient effect when the conductive filler is positioned between the high resistance region and the conductive region , and then the negative temperature coefficient effect is presented , and the temperature critical point is 80 DEG C ;
The conductive rubber exhibits a negative temperature coefficient effect in the range of 20 鈩，

本文編號：1693916