EFFECTS OF SOLUBILITY PARAMETER RELATIONSHIP BETWEEN ORGANIC LIQUID AND POLYESTER ON THE DYEABILITY OF THE POLYMER

Abstract

The effect of solvents with known solubility parameters on polyester filament yarn was investigated. The extent to which the solvents affected the morphological structure using scanning electron microscope, the degree of crystalline development using XRD, the tensile properties using Instron machine and the dyeability (dye exhaustion) were determined as a relationship based on time of solvent pretreatment. The ten solvents used [chloroform, acetone, benzaldehyde, nitrobenzene, dimethyl – o – phthalate, cyclohexanone, dimethyl formamide, benzyl alcohol, mcrezol and n-hexane] affected the fibre structurally with respect to time of pre – treatment and the temperature of solvent application. The degree of crack and voids obtained after pre – treatment increased relative to time and temperature for all the solvents pre – treated samples. These cracks and voids were more developed at 50oC pretreatment when compared with those treated at 30oC. Benzyl alcohol gave more cracks and voids development. Similarly the degree of crystalline development was highest for samples treated with benzyl alcohol. The degree of liquid retention was least in chloroform, acetone, and n-hexane treated samples, while the highest was recorded in m-crezol and dimethyl – phthalate. The tensile properties investigated after pre – treatment showed that similar patterns were obtained for all the samples. The degree of shrinkage was highest in benzaldehyde treated samples and was least in acetone samples with solubility parameters of 9.71and had very close shrinkage values of about 25%. Similar effects were observed for elongation and force at break (tenacity). The dyeing kinetics for all the solvent pre – treated samples showed similar pattern, the maximum dye exhaustion for the untreated (control) was 25%. Improvement in dye exhaustion was noted in the pre – treated samples and was found to be most in benzyl alcohol samples at 94%. Samples pre – treated in benzyl alcohol and dimethyl formamide gave best result.