Influence of Wax Content on Control and DMEU Crosslinked Cotton Fabrics

61-67<span style="font-size:12.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">amples of a cotton poplin fabric .at two stages of processing, viz. mercerize-scour (MS) and mercerize-acour-peroxide bleach (MBBS) having nearly the same wax contents were extracted with solvents to varying levels of comparable wax contents. These were further treated with 150g/litre DMEU. Both control and DMEU crosslinked fabrics were evaluated for various textile properties. From these evaluations it is found that with decrease in wax content, absorbency improves, but conditioned WRA, elongation at break, tear strength and flex abrasion of the controls decreases. However, on crosslinking with DMEU no decrease in these properties is observed. The overall performance profile shows that whereas resilience scores of control and  DMEU crosslinked MS and MSB are almost unaffected with decrease in wax content, the strength-abrasion scores show a decreasing trend more so in the case of controls then for DMEU crosslinked MS and MSB samples. </span

Studies on Chemically Modified Cotton Fabrics: Part IV-Physical Properties of DMEU Stripped Hydrocellulose and Hypochlorite Oxycellulose

7-13<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";color:black;mso-ansi-language:="" en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Reduction in the degree of polymerization (DPn) of a poplin fabric from 2300 to 350 was carried out by two techniques, viz. (i) alkaline hypochlorite bleaching of mercerized-scoured fabric (MS) to give hypochlorite Oxycelluloses, and (ii) acid hydrolysis of mercerized-scoured-peroxide bleached fabric (MSB) to give hydrocellulose. These were crosslinked with DMEU by the pad-dry-cure technique using MgCl2<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";color:#0e0e0e;mso-ansi-language:="" en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">.6H2O as catalyst and further DMEU stripped through urea-phosphoric acid (UPac) hydrolysis. From the study of the strength-abrasion properties of these treated fabrics it was found that (i) the MSB sample undergoes less "total" loss as compared to the MS sample on DMEU crosslinking<span style="font-size:11.0pt; line-height:115%;font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;="" mso-fareast-font-family:"times="" new="" roman";mso-fareast-theme-font:minor-fareast;="" mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"times="" roman";="" color:#0e0e0e;mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:="" ar-sa"="">. <span style="font-size:11.0pt;line-height:115%;font-family: " calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";color:black;mso-ansi-language:="" en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">However, the MSB sample suffers greater <span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";color:#0e0e0e;mso-ansi-language:="" en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">"permanent" loss compared to the MS sample and (ii) hydrocellulose undergo less "total" and "permanent<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";color:#0e0e0e;mso-ansi-language:="" en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">" losses compared to hypochlorite Oxycelluloses at all DPn levels<span style="font-size:11.0pt; line-height:115%;font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;="" mso-fareast-font-family:"times="" new="" roman";mso-fareast-theme-font:minor-fareast;="" mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"times="" roman";="" color:#0e0e0e;mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:="" ar-sa"="">. <span style="font-size:11.0pt;line-height:115%;font-family: " calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";color:black;mso-ansi-language:="" en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">However, the Oxycelluloses possess better strength-abrasion properties after DMEU crosslinking due to their higher values at the unfinished stage as compared to the hydrocellulose.</span

Studies on Chemically Modified Cotton Fabrics: Part III-Chemical Properties of DMEU Stripped Hydrocellulose and Hypochlorite Oxycellulose

1-6<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";color:black;mso-ansi-language:="" en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Two chemically modified cotton fabrics, viz. (1) hydrocellulose and (2) hypochlorite oxycellulose of degrees of polymerization (DPn) varying from 2300 to 350 were subjected to (i) catalyst treatment using 20 g<span style="font-size: 11.0pt;line-height:115%;font-family:" calibri","sans-serif";mso-ascii-theme-font:="" minor-latin;mso-fareast-font-family:"times="" new="" roman";mso-fareast-theme-font:="" minor-fareast;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"times="" roman";="" color:#0f0f0f;mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:="" ar-sa"="">/litre MgCl26H2O, (ii) DMEU finishing, (iii) urea-phosphoric acid (UPac) hydrolysis, and (iv) DMEU stripping. Evaluation of changes in functional groups and DPn has shown that catalyst treatment and UPac hydrolysis do not alter either the DPn or the contents of various functional groups of the two chemically modified fabrics. DMEU finishing introduces DMEU crosslinks. DMEU stripping by UPac hydrolysis causes a slight increase in DPn values<span style="font-size:11.0pt;line-height:115%;font-family: " calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";color:#0f0f0f;mso-ansi-language:="" en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">, but there is no change in the contents of functional groups of hydrocellulose. Similar treatment of hypochlorite oxycellulose causes reduction in DPn values and significant increase in aldehyde and carboxyl group contents.</span

Studies on Chemically Modified Cotton Fabrics : Part I-Chemical and Physical Properties of Hydrocellulose and Peroxide and Hypochlorite Oxycelluloses

37-44<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Three chemically modified cotton fabrics, viz. hydrocellulose, peroxide oxycellulose and hypochlorite oxycellulose having comparable DPn values in the range 1800-600 were prepared and their chemical and physical characteristics were studied. From the assessment of chemical properties, it is found that (i) hydrocellulose possesses high contents of aldehyde groups, predominantly of the reducing type, with low carboxyI and moderately high carbonyl groups, (ii) peroxide oxycellulose possesses moderate contents of reducing aldehyde groups and moderately high caboxyl and carbonyl groups, (iii) hypochlorite oxycellulose possesses very high contents of carboxyl groups along with the high non-reducing type of aldehyde groups and slightly low contents of carbonyl groups. The resilience properties of these chemically modified cotton fabrics are comparable and are also not affected by decrease in DPn value. Evaluation of strength-abrasion properties at different DPn levels shows that cotton fabric modified with sodium hypochlorite gives best performance at all DPn values, while the other two are comparable, The rate of fall in the strength-abrasion properties with decreasing DPn values is minimum for peroxide oxycellulose followed by hypochlorite oxycellulose and maximum for hydro cellulose.</span