废旧棉再生浆粕聚合度对其Lyocell纺丝及纤维力学性能的影响

Effects of the Polymerization Degree of Recycled Cotton Pulp on Its Lyocell Spinning and Fiber Mechanical Properties

为探索废旧棉再生浆粕聚合度对其Lyocell纺丝可纺性及纤维力学性能的影响,通过调整浆粕制备工艺,制备了不同聚合度(DP300~DP1172)的废旧棉再生浆粕,并考察了聚合度对再生浆粕的溶解性能、纺丝液的可纺性能以及所制备再生Lyocell纤维力学性能的影响.结果表明:废旧棉再生浆粕的聚合度显著偏低(DP300)时,纺丝稳定性相对较差;严重偏高(DP1172)时,无法连续稳定纺丝;在居中的聚合度范围内可连续稳定纺丝.随着浆粕聚合度的增高(DP300~DP725),所制备再生Lyocell纤维的干态断裂强度(3.35~4.72 cN/dtex)和模量(70.9~146.19 cN/dtex)等力学性能亦随之明显提升.相关研究有望为废旧棉织物回收制备高性能Lyocell纤维提供参考.

Under relatively stable fabrication conditions of the recycled pulp(RP),significant fluctuations in the degree of polymerization(DP)of the RP inevitably occurs due to the inherent batch to batch differences in waste cotton textiles.In order to invetigate the influence of the DP of recycled cotton pulp on its Lyocell spinning process and fiber mechanical properties,a series of recycled cotton pulps with different DP(from 300 to 1172)were prepared by adjusting the fabrication process of RP.Furthermore,the effects of DP on the solubility of RP in N-methylmorpholine-N-oxide,the spinnability of corresponding spinning solutions,and the mechanical properties of the regenerated Lyocell fibers were firstly investigated.Results showed that the solubility of the RP with low DP(300-725)was good and that with higher DP(1172)was relatively poor.As for the spinnability of corresponding spinning dope,the RP with significantly low DP(DP 300)shows relatively poor spinnability,while the RP with severely high DP(DP 1172)cannot be used for spinning.Those with appropriate range of intermediate DP can be used for continuous and stable spinning.In addition,the dry tensile strength(3.35-4.72 cN/dtex)and modulus(70.9-146.19 cN/dtex)of the regenerated Lyocell fibers were significantly improved as the increase of DP ranging from 300 to 725.Overall,the regenerated Lyocell fibers prepared from the RP with DP 578 and DP 725 present excellent mechanical properties similar to those of the Lyocell fibers fabricated from commercial COSMO wood pulp.An appropriate DP range of recycled cotton pulp suitable for Lyocell spinning utilization was obtained.This is expected to provide valuable guidance for industrial application of recycling waste cotton textiles to fabricate Lyocell fibers with high-performance.