Graft copolymerization to cellulose by sodium periodate

Abstract

It has been shown that acrylic monomer is easily grafted to cellulose by sodium periodate. The apparent activation energy of graft copolymerization is found to be 10.5 Kcal./mole, which indicates that polymer radicals formed by the attack of sodium periodate on cellulose initiate the graft copolymerization. The rate of the reaction increases with increasing reagent concentration of the reagent up to a certain concentration. At higher concentrations, sodium periodate produces more aldehyde groups in the graft copolymer and the grafted chains become shorter. The apparent number of graft‐initiating points is almost constant and independent of the sodium periodate concentration. Studies of homogeneous polymerization indicate that sodium periodate seems not to terminate the reaction of growing polymer radicals. On the other hand, when dialdehyde cellulose prepared previously by sodium periodate oxidation is grafted with methyl methacrylate, the grafted chain is shorter in the range of high content of aldehyde. The above observation indicates that the aldehyde groups formed in cellulose during the grafting reaction are likely to terminate the growing graft chains. The chain transfer constants for several sugars and alcohols with acrylonitrile as monomer were measured. The constants for sugars were found to be always higher than those for alcohols. The x‐ray diffraction patterns of the grafted cellulose with acrylonitrile give, in addition to the typical patterns of crystalline cellulose, lattice distances of 5.2 and about 3 A. which are attributed to the grafted polyacrylonitrile. The intensity distribution curve along the Debye‐Scherrer ring at the lattice distance of 5.2 A. leads to the conclusion that the crystallites of grafted polyacrylonitrile might be oriented along the direction of the fiber axis of the preexisting stock polymer. Studies on samples of cellulose of different fine structure would support the inference that, in the range of relatively low per cent grating the growing grafted chains on the surface of cellulose crystallites are oriented with the formation of crystallites along the lamellar plane of cellulose crystallites.

The preparation, characterization, and application of cellulose–MMA graft copolymers. I. The aqueous‐based preparation of cellulose–MMA graft copolymers

“…Trends observed in the effect of tR on the periodate-initiated, cellulose-MMA graft copolymerization reaction, were similar to those obtained by Toda et al 4 An induction period of between 2 and 4 h exists, during which no grafting occurs (Fig. 3 ) .…”

“…These values were calculated from weight loss/temperature data using the Broido method of analy~is.~' Immediately evident is the fact that, irrespective of the initiation route used, there is a decrease in EA for the decomposition of copolymers which have been grafted with MMA. Even at low grafting levels 4 1 Figure 6 shows the electron micrographs of a CWP sample (6.1) and three cellulose-MMA graft copolymer samples produced by Ce (IV) (6.2), periodate (6.3), and photochemical-initiation (6.4). For comparison purposes the samples depicted in Figures 6.2-6.4 were chosen so as to be of approximately the same weight percent level of MMA grafting (ranging between 69 and 79% ) .…”

A novel method for graft polymerization onto poly(ethylene terephthalate) film surface by UV irradiation without degassing

“…Photo-polymerization with NaIO, has already been studied by several research groups, but always included the procedure of degassing. [11][12][13]…”

Methacrylic Ester Polymers

“…Grafting methods used have included chemical (81,82), photochemical (83), radiation (83,84), and mastication (85). Methyl methacrylate has been grafted onto such diverse polymer backbones as cellulose (86), poly(vinyl alcohol) (87), polyester (88), polyethylene (89), poly(styrene) (90), poly(vinyl chloride) (91), and other alkyl methacrylates (92).…”