Preparation Of Gel-C₄H₄O₃ Size Agent And Application In Wool Yarn Sizing

In order to adapt to the production characteristics of multiple varieties and small batches of wool fabrics,single yarn sizing machines are generally used for wool sizing.But the size of the sizing tank is small,and the solid content of the high-temperature sizing slurry is easy to change.Therefore,room temperature sizing has become the main sizing technology for textile enterprises in recent years due to its advantages such as non-volatile size agent and stable size agent viscosity.This topic is mainly in view of the problems of gelatin gel at room temperature and poor toughness of size film when gelatin is used to sizing wool yarn,the modified gelatin protein(Gel-C₄H₄O₃)for sizing at room temperature was prepared by acylation of gelatin with succinic anhydride(C₄H₄O₃).Secondly,The reaction mechanism was scientifically researched,and the microstructure of Gel-C₄H₄O₃size agent was analysised by measures of infrared spectroscopy,proton nuclear magnetic resonance spectroscopy,X-ray photoelectron spectroscopy,scanning electron microscope and so on.Then,the relationship between the degree of acylation and the properties of Gel-C₄H₄O₃size liquid and size membrane was studied.Finally,sizing practice was carried out.The specific research contents are as follows:(1)Using gelatin as raw material and C₄H₄O₃as modifier,Gel-C₄H₄O₃size agent was synthesized by acylation method.The structure of gelatin and Gel-C₄H₄O₃sizes was characterized by FTIR,¹HNMR and XPS.The results show that the reaction between C₄H₄O₃and gelatin mainly occurs on the gelatin protein in the form of-CO-NH-bonds,and mainly occurs on the amino and imino structures of gelatin lysine through C=O bonds.(2)The acylation degree of Gel-C₄H₄O₃size agent was determined by formaldehyde titration.And the synthesis process of Gel-C₄H₄O₃sizes was optimized,and the most excellent organic process was gained:the quality ratio of C₄H₄O₃to gelatin was 1:16,the quality ratio of Na OH to gelatin was 1:50,reaction temperature was 50 degree centigrade and reaction time was 2 hours.(3)Through X-ray diffraction,differential scanning calorimeter,scanning electron microscope and other means,the relationship between the degree of acylation and the properties of Gel-C₄H₄O₃size liquid and size membrane was studied,including the viscosity of the sizes,relative molecular weight,mechanical properties of serous membrane,hydrophilicity and other related properties.The results show that compared with the existing acrylic,acrylamide or acrylate monomers-grafted gelatin,Gel-C₄H₄O₃had no gel at room temperature and Gel-C₄H₄O₃size membrane toughness increased significantly compared with gelatin.When the degree of acylation was 0.96,Gel-C₄H₄O₃showed a lower viscosity than gelatin at room temperature and strong adhesion on wool yarn,the breaking strength and elongation of its membrane are significantly increased,and the water solubility is excellent.(4)The Gel-C₄H₄O₃sizing agent with different acylation degree was used to sizing16.7tex JW,and the influence of acylation degree on the appearance,mechanical properties,wear resistance and hydrophilicity of Gel-C₄H₄O₃sizing was studied.The results show that when the acylation degree of Gel-C₄H₄O₃sizing reaches the maximum(0.96),the size liquid has completely penetrated into the yarn,the wool fibers are tightly bonded,the sizing surface is hairy,meeting the requirements of sizing.(5)Desizing experiments were performed on sizing of different acylation degrees in water at 70?,80?and 90?.The results show that when desizing at the same temperature,the desizing rate of sizing increases gradually with the increase of the acylation degree of the size.When the degree of acylation reaches 0.96,the sizing can be completely dessized in water at 70?(wool fabric washing temperature).(6)The ratio of BOD₅to COD_cris 0.8,so Gel-C₄H₄O₃is considered to be an easily degradable textile size agent.Figure 34,table23,reference 93.