Determination And Elimination Of Interference Factorsin PVA Fast Identification

With people gradually paid more and more attention to the environment protection problems of polyvinyl alcohol (PVA), more and more countries adopt the textile environmental standard. PVA, defined as a kind of impurity finishing mixture, is gradually taking out of service for its defect of biodegradability.This research is concentrated in the fast PVA testing method, especially the disturbing factors in the PVA detection and the elimination of this disturbing factor. So that it will provide an available fast PVA testing method for practical textile manufacture.In experiment we adopted a way of mixing PVA with several kinds of usual finishing mixture, such as starch, CMC, sodium alginate, polyacrylate, polyvinyl acetate etc. By this way, we can detect PVE in the mixture efficiently and analyse the disturbing factor of the other composition in the mixture, in addition, we can find an effective way to eliminate the disturbing factors. Conclusion:1) polyvinyl alcohol has a sensitive and fast color development with iodum. By this iodum-boracic acid method, we can detect the existence of PVA qualitatively and effectively.2) By the way of check the singleness PVA and the mixture with other finishing mixture, we can justify that the minimum detectible thickness of PVA, which is not affected by the component of finishing mixture, is 0.10%.3) Both starch and PVA is polyhydroxylated compound. Meeting with iodum, they have the same color development. Experiment confirmed that: Starch has disturbance to the qualitative detection of PVA, but we can eliminate it by using the character of they have different reaction with acid (starch will hydrolyze into glucose in acid).4) CMC, whose well solubility makes it suitable to mix with other mixture, has no disturbance to the detection of PVA.5) Polyacrylic acid has no disturbance to the detection of PVA.6) sodium alginate, which also has the blue color development with iodine, has disturbance to the PVA detection and this disturbance can't be eliminated.7) Because of the action of acid and alkali in textile finishing process, polyvinyl acetate could transform into polyvinyl alcohol (PVA). It can be confirmed that polyvinyl acetate do have disturbance in PVA detection and this disturbance can't be eliminated.