Studies On The Formation Of PBST Fibers And Its Dyeing Properties

As one of aliphatic/aromatic copolymer,Poly(butylene succinate-co-butylene terephthalate)(PBST) is an important category for the balance of its biodegradability and physical properties.PBST copolyesters were efficiently synthesized from the starting materials of dimethyl succinate,dimethyl terephthalate and 1,4-butanediol.Now,the researches on PBST not only focused on film samples,but also on biodegradable fibers.When the molar fraction of BT comonomers of the prepared products are 70%,melting peak temperatures at 180℃and decomposion temperatures at 377℃,the PBST copolyesters appeared the good spinnability.In the above cases,this investigation raise the speed of spinning on the basis of 1000 m/min,and fiber processing,resultant fiber properties and fabric dyeing properties were studied.Firstly,the melt-spinning process of PBST copolymer was investigated as the key point.Based on the studies,the molecular weight plays a dominant role in spinnability of PBST.When the molecular weight exceeded 1.2×10~5,the PBST copolyesters appeared the good spinnability.Moreover,there was a wide range of melt-spinning temperature for PBST copolyesters and the optimum was 240～260℃. The mechanical properties of PBST fiber was improved by increasing take-up velocity,the optimum spinning speed was 3000 m/min.From the experiments,the suitable drawn processing temperatures were selected for 50℃and heat-setting for 140℃.In the above parameters,the strength of last drawn PBST fibers can get maximum of 3.3 cN/dtex.Furthermore,elastic recovery and viscoelasticity of PBST fibers were studied.The result showed that PBST fiber has good extensibility, softness and fatigue resistance.PBST fiber has also superiority on elastic recovery,especially for lowelongation.When PBST fribers were elongated to 15%,the elastic recovery rate up to over 97.56 percent; when set the elongation of 20%,the elastic recovery rate of PBST fibers still up to 88.3%.And PBST fibers were not breaken when elongate repeatedly at 20%.In addition,a dyeing process of the biodegradable PBST fabric with disperse dyes was studyed.The result showed that PBST fabric could be dyed in nearly natural condition;it has a certain dye adsorption at 10℃, and at 70℃it achieved deep color.PBST fabric has high rate of dye-uptake,good level dyeing property and color fastness.Its wet and dry color fastness to crocking are up to level 5,and color fastness to washing reached more than level 3.The shrinkage of PBST fiber in the water of 100℃reached 22.3%,and the longitudinal and latitudinal shrinkage of PBST fabric reached 20%and 16%respectively.However,in the water of 70℃,the fibers shrinkage and fabric shrinkage of PBST were 12.7% 12%and 8%respectively.From the experiments,PBST fabric shows good dyeability and primary fabric handle at 70℃.