Radiation-Indoced Interaction of Styrene with Cotton

Abstract

The efficiency of activation and interaction of styrene with fibrous cotton cellulose was increased by the indirect effects of radiation-excited cotton and of methanol and N,N-dimethylformamide. The high radiochemical yields indicated that a chain reaction was initiated. The polystyrene was located within the growth layers of the fibers. The elongation-at-break and resistance to wetting of polystyrene-cotton were greater than that of cotton, and the average stiffness, less. The polystyrene-cotton was thermoplastic.THE basis for these studies was the hypothesis that the interaction of polystyrene with cotton could yield products having desirable thermoplastic properties and increased water repellency. Radiationinduced interaction of styrene monomer with cotton would offer the possibility of more than a surface interaction in that monomer could he allowed to diffuse into the fiber prior to polymerization. It has lweii reported that about 63 electron volts of energy are required to produce a free radical of styrene ( 21 J . The aromatic ring in styrene probably tends to stahilize the molecule, resulting in a low efhciency of free radical yield. It can be calculated from data previously published that at f dosage of about 1 megaroentgen, in an oxygetl atmosphere, about 14 electron volts of energy are required per scission of the cotton cellulose molecule )6. 11, 12 [ . It t is s generally assumed that radiochemical reactions of organic molecules ia a solid state are due entirely to free radicals [13{. Obviously, then, if 5ignificant interaction of styrene with cotton is to be initiated hy high-energy radiation and at, the same time the fibrous structure of the cotton is to be retained, the efhciency of the radiochemical yield for activated styrene must 1e increased.A number of reports on the interaction, upon high-energy irradiation, of styrene with cellulose --~--~--films [ 14, 16 j, filter paper ( 1-1, 23 [, cellulose esters ( 25, 26, 27], cotton [18, 19, 20, 23 ] , and regenerated cellulosic fibers , [ 5, 20, 24 ~ have been pullished. The swelling of the cellulose with water [241 J and the immersion of cellulose in solutions of hydrogen peroxide [18, 19] and of formamide and methanol ( 5, 20, 24 during irradiation have been claimed to increase the interaction of styrene and cellulose. Radiation dosage levels used to induce interaction of styrene with cellulose would, in most cases, result in the depolymerization and loss of the fibrous structure of cotton.The indirect effects of radiation-excited cotton, in the presence of methanol and :~',:~'-dimethylforntaiiiide, on the efficiency of activation and interaction of styrene with fihrotts cotton cellulose are discussed in this report. The effects of the interaction of styrene with cottoa on its textile properties are also reported., . , Experimental Alaterials Deltapine cotton, spun into 7s/3 yarn and wound into 18-yd skeins, each weighing 4 g, was purified by extraction with hot ethanol followed hy boiling in 1 ~/~ ~ aOH solution, with proper precautions to prevent...

Radiation induced graft copolymerization of vinyl monomers and their binary mixture onto rayon fibre

“…A simple way of overcoming this obstacle is to carry out mutual irradiation grafting of cellulose in the presence of a swelling agent, which penetrates the cellulose and allows the monomer to enter inside the polymer matrix. The use of solvent‐monomer mixtures rather than pure monomer was found by various investigators16, 17 to give substantially increased grafting. It is believed that the success of this method is due to the combination of two effects.…”

Electron Microscopy

“…Styrene monomer that was reacted with cotton by exposure to a cobalt-60 source was examined electron microscopically by Demint ei al. (118). The polystyrene was found within the growth rings of cotton.…”

“…Synthetic fibers, once thought to be homogeneous, have been recognized as being composed of primary and secondary structures (31,98,229,400). There are also wide varieties of chemically modified physically treated, delicately coated and intimately coordinated fibers (55,56,57,118,390,391,433,515). When chese complexities are added to those of integration and fabrication, it becomes evident that an investigator must analyze his problem and plan his microscopical research with due regard to the number and relationship of molecular associations present, using a classification scheme such as that proposed by Rochow (387,388,389).…”

Vinyl Cellulose Copolymers

“…It has been suggested that the vinyl-cellulose copolymer would have some of the properties of both the cellulosic fiber and the grafted polyvinyl polymer [23 . We have previously reported changes in properties of cotton fibers, yarns, and fabrics on radiation-initiated graft copolymerization reactions with several vinyl monomers [3-5, 7-13, 15, 17-19, 21, 22). We have shown that these types of reactions significantly changed the elastic recovery properties of fibers [13], the thermal stress properties of yarns [ 15 ] , the flex and flat abrasion resistances of fabrics [ 19 ] , the distribution of the grafted copolymer within the fibrous structure [4,8,13,18,19,21,33,34], and other properties, such as, rot resistance of cotton [19].…”