Carbonization of Polyacrylonitrile Composites with Nitrogen-containing Cellulose Derivatives

Carbonization of some cellulose ethers and their graft copolymers with polyacrylonitrile

“…Depending on the concentration and mutual orientation of the cyclic products of the reaction of PAN and AOEC, intermediate polycyclic compounds with a crystalline structure can form, and their melting is detected by DTA. Similar effects have also been observed with PAN3ACMC copolymers, with the only difference that the endothermic effect was the most pronounced in the range 440 3 460oC [1].…”

“…As noted previously, carbonization of cellulose ethers and some other cellulose derivatives occurs mainly in three steps; their kinetic features were considered in [1,539]. The most interesting for us, in the context of this study, were the quantitative and specific qualitative characteristics directly related to the carbonization step occurring, as a rule, above 400 3500oC.…”

“…Graft copolymers of cellulose and polyacrylonitrile (PAN) simulate the structure of precarbonizates obtained by joint thermolysis of cellulose and its nitrogen-containing derivatives with PAN [1].…”

Prospects for Using Polyacrylonitrile for Preparing Carbonized Polymeric Composites

“…As for the related reactions with r-PAN samples, the prevalence of heterostructures, presence of low-molecular-weight PROSPECTS FOR USING POLYACRYLONITRILE 797 fractions, broad MWD, significant branching, and presence of various functional (mainly oxygen-containing) groups make possible a wide spectrum of low-energy reactions yielding diverse reactive byproducts. These factors, along with the fact that the temperature ranges of the highest reactivity of both components coincide (200 3300oC), are necessary conditions for efficient cocarbonization with cellulose derivatives (ethers, esters, chitin, chitosan) releasing a number of reactive compounds in thermal degradation [22,23]. It was also shown in [22,23] that cyano derivatives of these carbohydrates are characterized by a high yield of the coke residue.…”

“…Thus, the conditions of PAN activation can correspond to the conditions of thermochemical reactions with other polymers. The most suitable for this purpose are cellulose derivatives; their thermal degradation occurs most actively in the same temperature range (200 3300oC) as the cyclization of PAN [22,23].…”