Rubber Oxidation and Aging Studies Safe Limits of Sample Thickness
Rubber Oxidation and Aging Studies Safe Limits of Sample Thickness
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橡胶氧化和老化研究样品厚度的安全极限
DOI：
10.5254/1.3543127
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发表时间：
1951
影响因子：
1.5
通讯作者：
H. Winn
中科院分区：
文献类型：
--
作者：
G. Blum;J. Shelton;H. Winn
橡胶氧化和老化研究的样品厚度的安全限度，这样的化学反应，而不是扩散速率将是速率控制已被调查的天然橡胶硫化胶和四种合成橡胶类型。对于涉及整个氧化范围的研究，包括快速吸氧的自催化阶段，如果希望避免扩散的限制，则常规的0.075英寸厚度对于加速老化和氧化研究常常是不令人满意的。只有在GR-S黑料中，发现该厚度在高达100° C的温度下是令人满意的。其他原料，包括天然橡胶、丁腈橡胶-NXM和氯丁橡胶炭黑和树胶原料，都需要更薄的样品，以确保观察到的氧气吸收速率不受扩散的限制。一种计算样品厚度的可能极限值的方法，在该值以上，自催化阶段的氧化速率受到扩散的限制。
Abstract Safe limits of sample thickness for rubber oxidation and aging studies, such that the chemical reaction rather than the rate of diffusion will be rate-controlling have been investigated for natural-rubber vulcanizates and for four synthetic-rubber types. For studies involving the entire range of oxidation, including the autocatalytic stage of rapid oxygen absorption, the conventional 0.075-inch thickness is frequently not satisfactory for accelerated aging and oxidation studies if it is desired to avoid limitation by diffusion. Only in the GR-S black stock was this thickness found to be satisfactory up to a temperature of 100° C. The other stocks, including natural rubber, Butaprene-NXM, and Neoprene black and gum stocks all require thinner samples to ensure that the observed rate of oxygen absorption is free of limitation by diffusion. A method of calculating the probable limiting value of sample thickness, above which the rate of oxidation in the autocatalytic stage is limited by diffusion, has...