The kinetics of cellulose fiber degradation and correlation with some tensile properties

Abstract

Cellulosic degradation of cotton and flax yarns caused by light, heat and heterogeneous acid-catalyzed hydrolysis was studied. These processes were followed by measuring changes in intrinsic fluidity (l/DP,,): two principal stages, characterized by different zero-order kinetics, take place. A relation between changes in intrinsic fluidity with some mechanical properties of the same yarns during the degradation process was found.

Preservation treatments of aged papers by supercritical carbon dioxide

“…1, the percent amount of the initial b-glucosidic bonds of cellulose which have been broken at any degradation time linearly increases with time, according to two consecutive constant-rate stages, the second one being in any case slower than the first one. This is in agreement with previous results obtained with different types of cellulosic materials: [13,[15][16][17] the rate of glucosidic bonds break, occurring according to a first order kinetic law, depends on the polymeric environment in which they are located, i. e. on whether they are in the amorphous or in the crystalline region of the cellulose polymer.…”

Kinetic studies on the accelerated aging of cellulosic materials

“…Previous studies [1][2][3] evidenced that in general the degradation of cellulosic materials actually occurs according to an apparent zero-order kinetics, though with rate coefficients which only seldom remain constant within the whole process. Indeed, a relatively high number of particularly sensitive bonds may initially be broken in a rather short lapse of time 4) .…”

“…It is well known that cellulosic fibers, as other polymeric fibers, undergo degradation under the action of external environmental agents [1][2][3] , such as light, heat, microorganisms (i.e. bacteria, fungi, molds), insects and chemicals.…”

Flexural Properties of Long Bamboo Fiber/ PLA Composites

“…The flexural strength leveled off at molding temperature of 120˚C -160˚C, but decrease after 180˚C. The strength of the mold product decreased because strength of fiber in itself decreased [13]- [15]. Therefore, it can be said that 160˚C is the most suitable molding temperature.…”