- 學位論文
EPDM 橡膠彈性體導電複合材料電氣與機械性質之研究
A Study on Electrical and Mechanical Properties of Conductive EPDM Rubber Elastomer
摘要
光電製造業為了改善輸送玻璃基板的滾輪與基板之間的接觸表面摩擦力過小問題，所以在傳輸滾輪上方加裝了使用 EPDM 橡膠製成的 O-Ring，以增加滾輪與玻璃基板表面摩擦力，並改善玻璃基板在輸送過程中與傳輸滾輪之間，因表面接觸摩擦力不足而發生滑動的問題。但伴隨產生的問題為玻璃基板與橡膠間的表面摩擦力增加，所產生的靜電會殘留於玻璃基板上方的金屬導線，且當靜電累積到一定量後，所釋放出的電量會造成金屬導線受到破壞。 因此本篇研究的目的主要是將絕緣之三元乙丙橡膠(EPDM)與具有導電性質的碳黑塑料摻混後，製成具有導電性的 EPDM 橡膠彈性體複合材料，以導除產品在輸送過程中因與橡膠摩擦所產生的靜電，並達到改善靜電滯留於產品金屬線上方所產生的靜電破壞問題。 在填充導電塑料中，一般最被廣泛應用便為碳黑(Carbon black)，因為碳黑具有加工性好、成本低廉、以及導電性佳等特殊性質，因此在本篇研究中添加於三元乙丙橡膠(EPDM Rubber)所使用之導電塑料便為奈米級的碳黑(EC-300J 與 EC-600J)，並探討其電阻係數與機械性質變化。實驗測量方法包括以下:1.使用阻抗分析儀分析各組成摻合橡膠之電阻係數的變化；2.在機械性質之測定則以抗拉強力試驗予以分析；3.在導電橡膠彈性回復率的變化則以濳變分析儀予以分析。 實驗結果包括兩部分: 1.根據阻抗分析儀分析的結果顯示,在三元乙丙橡膠(EPDM rubber)中，隨著 EC-300J 與 EC-600J碳黑用量增加達到 13.79 wt% 與 9.64 wt% 時，導電橡膠的表面電阻係數可降到104Ω 與 103Ω；根據濳變分析儀分析的結果顯示，隨著 EC-300J 與 EC-600J碳黑用量到達13.79 wt% 與 9.64 wt%，導電橡膠的表面電阻係數雖可降至104Ω 與 103Ω，但其彈性回復率卻會因碳黑含量的增加而下降至64% 與 61%。 2.實驗將硫的用量由 1.16 wt%提升至 4.49 wt% 時，可將添加 13.79 wt% EC-300J 碳黑的導電橡膠彈性回復率由64% 提升至 74%，且電阻係數可維持在 104Ω，當硫的添加量持續增加至 8.60 wt% ，雖可提升添加13.79 wt% EC-300J 碳黑的導電橡膠彈性回復率至76%，但卻會導致導電橡膠的電阻係數由 104Ω 增加至106Ω，此乃因過量未與橡膠交聯的硫析出於橡膠表面，而導致橡膠的表面電阻係數上升。而在加入 13.79 wt% EC-600J 導電橡膠要使其電阻係數維持在 103Ω，且要使彈性回復率維持在 75%，除了需增加硫的用量至 4.49 wt% ，還需將熱壓壓力由 40kgf 提升至 150kgf，方可使橡膠在相同的交聯時間(10分鐘)下，迅速增加橡膠與硫的交聯程度，以達到維持導電橡膠彈性體的彈性回復率為 75%之水準。
並列摘要
To improve the problem of insufficient surface contact friction during the delivery course between the wheel and the substrate, the optical manufacturers install O-Ring made by EPDM rubber on the top of the transmission rollers to increase the surface friction between the wheel and the substrate and improve the sliding occurrences due to the insufficient surface contact friction. However, when the surface contact friction between the glass substrate and the rubber increases, the generation of static electricity deposit on glass substrate at the top of the metal wire. After the static electricity accumulates to a certain amount, the release of the electricity would cause metal wires damaged. Therefore, the purpose of the study is mainly to mix the insulative the EPDM rubber (EPDM) with the conductive carbon black to produce a conductive EPDM rubber elastomer which can not only remove the static electricity due to the surface friction during the delivery course but also improve the damage of static electricity deposited on glass substrate at the top of the metal wire. In general, the most widely used of materials filled in the conductive plastics is carbon black, because of the special properties of good process ability, low cost, and good electrical conductivity etc. According to these properties, the nano-carbon black (EC-300J and EC-600J) is chosen as the conductive plastics adding to EPDM rubber in the study. Furthermore, we try to explore the changes in electrical and mechanical properties. Experimental methods include as follow:(1)Using the resistive analyzer to measure the changes of the coefficient of surface resistance among the different compositions of blending rubber.(2) Using the tensile strength tests to measure the mechanical properties among the different compositions of blending rubber.(3)Using the creep analyzer to measure the changes of the elastic recovery rate among the different compositions of blending rubber. Experimental results include as follow: (1)The resistive analyzer shows that in EPDM rubber, when the EC-300J and EC-600J increases the amount of carbon black to 13.79 wt% and 9.64 wt%, the coefficient of surface resistance of the conductive rubber elastomer could be reduced to 104Ω and 103Ω.The creep analyzer shows that when the EC-300J and EC-600J increased the amount of the carbon black to 13.79 wt% and 9.64 wt%, the coefficient of surface resistance of the conductive rubber elastomer could be reduced to 104Ω and 103Ω,but at the same time the elastic recovery rate would be decreased to 64% and 61% as a result of the increase amount of the carbon black. (2)When the amount of sulfur raises from 1.16 wt% wt to 4.49 wt%, the elastic recovery rate of the 13.79 wt% EC-300J is promoted from 64% to 74%, and coefficient of surface resistance could be maintained at 104Ω.When the added amount of sulfur continues to raise to 8.60 wt%, the elastic recovery rate of the 13.79 wt% EC-300J is promoted to 76%, but the coefficient of surface resistance would be increased from 104Ω to 106Ω. It is because excessive sulfur couldn’t cross-link with the rubber but precipitated the rubber surface. It caused the coefficient of surface resistance increased. Moreover, to maintain the coefficient of surface resistance at 103Ω and the elastic recovery rate at 75% of the 13.79 wt% EC-600J, it is necessary to increase the amount of sulfur to 4.49 wt%, and to upgrade the hot-pressing pressure from 40kgf to 150kgf. So that the cross-linking level between the rubber and sulfur would increase rapidly within the same cross-linking time(10 minutes) to maintain the better the elastic recovery rate of the conductive rubber elastomer at 75%.