首页>
外文期刊>journal of applied polymer science
>Effects of substitution of triphenylmethyl groups into cellulose on the fine structure and thermal properties of the products
【24h】
Effects of substitution of triphenylmethyl groups into cellulose on the fine structure and thermal properties of the products
展开▼
机译：Effects of substitution of triphenylmethyl groups into cellulose on the fine structure and thermal properties of the products
AbstractMercerized cellulose in the form of 7/2 yarn was reactivated with 17.5 sodium hydroxide and then heated at 100°C. with 5 moles of trityl chloride, in pyridine, per anhydroglucose unit. The time of reaction was varied, giving ether derivatives of the cellulose containing 0.31–0.79 triphenylmethyl groups (DS) per anhydroglucose unit. Controls consisted of (1) the untreated cellulose yarn and (2) a portion subjected to all the reaction conditions except the reactant. The density of the product decreased hyperbolically with increasing substitution. The mixed x‐ray pattern of the untreated control cellulose (35 cellulose I, 43 cellulose II) was largely converted by the activation treatment (10 cellulose I, 53 cellulose II). As reaction proceeded the crystal structure largely disappeared. The assumption is that substitution was confined almost exclusively to the primary hydroxyl position. The behavior of tensile stiffness, elastic recovery, and work recovery was explored at temperatures from about 25 to 225°C. Considerable improvement, which generally increased with increasing substitution, was observed in both elastic and work recovery at all temperatures st
展开▼
