No abstract

No abstract

A permanent-type flame retardant based on a bromoform adduct polymer of allyl phosphonitrilate in combination with THPC resin has been developed for use with cot ton fabrics. The combination flame retardant is applied to fabrics from aqueous emul sion using conventional textile finishing equipment. The flame retardant is very effi cient; 8-oz. twill and sateen are made highly flame-resistant with as little as 13% resin add-on.

Linters and cotton sewing thread have been acetylated with ketene. Treatment involves preswelling with water, removal of excess water by extraction, suspension of the cotton in an inert solvent (preferably ether) containing a catalyst (preferably perchloric acid), and treatment with ketene as prepared by pyrolysis of acetone.Samples containing up to 17% acetyl retained their fibrous structure with only slight degradation. The ketene acetylation was accompanied by an objectionable polymerization of ketene which produced a yellow to dark brown coloration of the sample. The color could be removed by hot alcohol. Although the emphasis was on the reaction of water-activated, solvent-dehydrated cellulose with ketene, some experiments were tried in which the cotton was swollen with acetic acid before introduction of ketene. Acetylation was probably due to the acetic anhydride formed.

Bromine-containing derivatives of phosphonitrilic chloride were investigated as pos sible durable flame retardants for cotton fabrics. These, including brominated allyl phosphonitrilate, 2, 3-dibromopropyl phosphonitrilate, and the bromoform adduct polymer of allyl phosphonitrilate, were applied to cotton fabrics as polymeric products from or ganic solvent or from aqueous emulsions. Evaluation tests on tear strength and the durability of the flame resistance to laundering were made.