The Effect of Rubber Compounding on Rubber Properties

The Effect of Rubber Compounding on Rubber Properties
We have just discussed the various compounding ingredients and have indicated their prinecipal affects, new we shall look at rubber compounding from a different angle. We shall describe how the properties of the vulcanizate can be modified and how the rubber compound can adapt to manufacturing operations by the addition of suitable ingredients.
Tensile Strength This property, which is seldom encountered in the service conditions of rubber, is often used as a measure of their quality.
We have noted the effect of reinforcing and inert fillers on the tensile strength. We have also mentioned that addition of reclaimed rubber, factice, crumb rubber and plasticizers would adversely affect the tensile strength, Besides these factors the tensile strength to a certain degree.
Modulus A high value of the modulus indicators that the vulcanizate is hard and stiff and a low value points to a soft, flexible product. The modulus can be controlled best by proper choice of accelerator and fillers.
Hardness Rubber article seldom call for a lower hardness than that of a pure gum stock. If necessary, the hardness can be reduced by addition of large quantities (up to 80 PHR) or factices or softeners but this also causes reduction in the mechanical product will be.
Tear And Abrasion Resistance These two properties vary in substantially the same manner within certain limits. If the highest possible values are sought, carbon black should be used. Additional improvement in these properties can be achieved by proper choice of the accelerator MBT and its derivatives being especially recommended. Reclaimed rubber, factices, and curmb rubber cause a pronounced decrease in these properties.
Aging And Fatigue Resistance For resistance to repeated deformations, overfilled, or highly pigmented compounds should be avoided; also, it is imperative to use optimum vulcanization conditions.
For heat resistance, large quantities of fillers of plasticizers and sulfur should be used, The EV and SEV systems have been employed recently in many heatresistant compounds and prove successfully due to higher bond energy of mono and disulfur linkages.

New Words and Expressions
1. modify 改良,改性
2. adapt 适应,改编
3. adapt to 适应于
4. factice 油膏
5. crumb 颗粒,点滴,面包屑
6. crumb rubber 颗料胶
7. adversely 相反地
8. influence 影响
9. stiff 僵硬的
10. gum 纯胶,树胶,涂树胶
11. stock 胶料
12. manner 方式,态度
13. seek 寻求,企图
14. derivative 衍生物
15. pronounce 发音,宣告,表示
16. pronounced 显著地,断然地
17. fatigue 疲劳,使疲劳
18. deformation 变形
19. overfill 过量填充
20. overfilled 过量填充的
21. pigment 着色剂
22. imperative 强制的,不得不的
23. optimum 最佳的,最适宜的
24. employ 使用,雇用
25. due 应付,适当,应到的
26. due to 由于,起因于
27. bond 键,联络,契约
28. mono- 单，一
29. di- 双，二
30. mono and dissulfur 单硫和双硫
31. linkage 键