Study On The Synthesis And Properties Of Quaternized And Dodecenylsuccinated Corn Starch

To solve the problem that sizing performance of starch cannot meet its demand in warp sizing due to its bad adhesion and poor tensile properties of its films.Firstly,a series of quaternized and do-decenylsuccinated corn starch(QDS)with different degrees of substitution of hydrophilic quaternary ammonium groups(DS1)and the substitution of hydrophobic dodecenyl succinate groups(DS2)were prepared by reacting cornstarch with N-(3-chloro-2-hydroxypropyl)trimethylammonium chloride(CHPTMA)used as etherifying agent for the preparation of quaternary ammonium cationic starch(QS),and further react with dodecenly succinic anhydride(DDSA).QDS is characterized by the analysis of infrared spectroscopy and electron microscopy.The analysis of infrared spectroscopy demonstrates that quaternary ammonium groups and dodecenylsuccinate groups are successfully grafted onto the backbones of starch.And the analysis of electron microscopy shows that the modification of starch with the CHPTMA and DDSA mainly occurs on the surfaces of starch granules.Secondly,the properties of cooked QDS paste such as apparent viscosity,light transmittance,retrogradation,adhesion,and film properties were studied.The results showed that the viscosity and viscosity stability of the QDS paste increased compared to the ATS,and the light transmittance and anti-condensation of the paste were significantly improved.Compared with QS,QDS had a good compatibility with anionic PAA,and had not occurred an obvious retrogradation.Compared with dodecenyl succinic acid esterified starch(SSAS),QDS had the excellent adhesion to polyester and cotton fibers.With the increase in the DS1/DS2 ratio,adhesion of QDS to cotton roving increased and its adhesion to polyester roving increased and then decreased.When DS1/DS2 value approached 2,the adhesion to polyester roving reached the maximum.The crystallinity of the QDS film decreased compared to the ATS film.Tensile strength of QDS film decreased and then increased as the ratio of DS1/DS2 increased and reached its minimum as the ratio of DS1/DS2 was 1.Thirdly,blending properties of QDS and PVA was also investigated.The results showed that QDS had good compatibility with PVA.Blending of QDS and PVA could improve the adhesion of QDS to polyester and cotton fibers and increase the tensile properties of QDS films.When the blending ratio was 50/50,adhesive strength of the blends to polyester and cotton fibers increased and tensile strength of the blended films increased with the increase in the degree of polymerization and that of alcoholysis of PVA,When QDS is blended with PVA 1799 The tensile fracture strength of the 50/50 blend film is the smallest,with the increase in the blending ratio,the strength of the blended film increased and then decreased,and the strength reached the maximum value as the ratio was 70/30.When the ration of QDS/PVA1799 was 50/50,the minimum value in the adhesionwas showed.With the increase in the ratio,adhesion of the blends pastes to cotton and polyester roving increased and then decreased and reached the maximum value at 70/30.Finally,QDS was used to sizing blending warps of polyester and cotton fibers,the experimental results showed that QDS with the DS1=0.031 and DS2= 0.016 exhibited the best properties such as the reduction of the hairiness of sized yarns,strong tensile strength and abrasion resistance.The analysis of the microscope showed the hairiness has an obvious decrease.The sizing performance of the QDS to the polyester-cotton blended yarn is better than that of the QS and SSAS.