Polyvinyl chloride (PVC) fibers (woolly, unstretched and streched) which have imbibed solutions of α, α′-azo-bisisobutyronitrile (AIBN) or benzoyl perozide (BPO) were heated mainly with aqueous solutions of acrylonitrile (AN) for the graft polymerization. The heating was carried out at 40° to 75°C in the presence of air in sealed tubes. Concentrations of catalyst solutions were 0.2 to 3%, and a benzene-petroleum benzine mixture (1:1 by volume) or benzene-methanol mixtures was used as solvent for catalysts. When PVC fibers which have imbibed catalyst solutions were heated with an AN-ligroin mixture (1:2 by volume), the grafting did not proceed smoothly, but high graft efficiencies could be obtained by heating in a 10 vol% aqueous solution of AN. A catalytic effect of BPO was similar to that of AIBN. In general, the grafting rates onto PVC fibers were in the order of woolly>stretched>unstretched one. When ca. 3.0g of AN was used per 1.0g of fibers, ca. 2.5 g of AN could be grafted to give easily openable fibers under favorable conditions. Heat shrinkages of PVC fibers were remarkably decreased by the grafting. The shrinkage was dependent not only on the degrees of grafting, but also on the conditions of the grafting and heat-treatments of the fibers after the grafting.
Various fibers (cotton, rayon, polyvinyl alcohol, nylon, polyvinyl chloride and polyseter fibers) which have imbibed solutions of radical initiators (ammonium persulphate, hydrogen peroxide, α, α′-azo-bisisobutyronitrile [AIBN] and benzoyl peroxide [BPO]) were heated with methyl methacrylate or methyl acrylate for graft polymerization. Water, aqueous methanol, benzene and a benzene-petroleum benzine mixture were used as solvents of catatyst, and the monomers were applied without solvent or as solutions whereby methanol, ethyl acetate and benzene being used as solvents. The polymerization was carried out at 60 to 90°C in the presence of air in sealed tubes. The graft polymerization proceeded smoothly onto cellulose, polyvinyl alcohol and nylon fibers, but with difficulty onto polyvinyl chloride and polyester fibers. In general, ammonium persulphate and hydrogen peroxide were more effective than AIBN and BPO as initiators of the grafting. The grafting tendencies of various monomers were in order of styrene>methyl methacrylate>methyl acrylate>acrylonitrile>vinyl acetate. The result may be interpreted from the viewpoint of reactivites of monomers and resulted polymeric radicals.
Two acetate (acetic acid value: 52.55 and 54.23%) and a triacetate fibers were reacted with tolylene diisocynate (TDI) vapour at different temperatures under normal or reduced pressures. It is deduced that the hydroxyl groups of the acetate or the triacetate are reacted with isocyanate group and crosslinked together. This research was undertaken to modify the mechanical properties of acetate and triacetate fibers mainly by the vapour phase method. The reaction rates and the apparent activation energies of the reactions between acetate fibers and TDI were determined. The mechanical properties and the solubilities of the modified acetate and triacetate fibers were also measured. Results obtained are as follows: (1) The reaction rate increases with rise of reaction temperature and at 150°C for 1.5hr, the percentages of combined TDI become more than 40% and 10% for the acetate and for the triacetate respectively. (2) The apparent activation energies of the TDI-acetate reactions in a vapour phase are 12.8Kcal/mol for the acetate and 7.8Kcal/mol for the triacetate. This is probably due to higher affinity of the triacetate toward TDI than the acetate. (3) With an increase of the percentage of TDI combined, breaking load of the fiber remains almost constant, elongation decreases and initial modulus, yield value and elastic recovery increase. (4) Elastic recovery of the acetate fiber rises by grafting of poly (butyl acrylate) and increases further by successive TDI treatment. (5) The acetate and the triacetate combined with more than 7_??_8% of TDI become practically insoluble in acetone and methylene chloride.
The reaction of cellulose with milk casein and epichlorohydrin was studied in order to prepare a viscose fiber grafted with milk casein. 15% of milk casein in an aqueous solution of 1% sodium hydroxide was reacted with 1_??_3% of epichlorohydrin to the weight of casein and then the product was added to viscose, which contained 15_??_20% of casein to the weight of cellulose. The spinning was carried out by the usual viscose spinning method and a new type of chemical fiber conbining cellulose with milk casein was prepared. This method of fiber-making is not that of merely spinning the mixture of cellulose and milk casein. Thus the properties of fiber obtained extensively varies in its properties depending on the amount of grafting agent (epichlorohydrin) used as well as on the relative amounts of the two polymers. In addition to the usual properties of viscose fiber, this fiber grafted with milk casein has such good properties as the the affinity to dyestuff for wool, fastness to light, burning resistance, heatretaining property and resistance against wool-attacking insects, moulds and mildews.
Reaction and spinning condition were studied in order to obtain 6, 10 nylon fiber by interfacial polycondensation between hexamethylendiamine and sebacoyl chloride by using a J-tube of Magat and Strachan. The polycondensation condition for maximum intrinsic viscosity was clarified. The effects of stretching and heat treatment on the mechanical properties of the fiber were also investigated.