Zheng Li,Zi Jian He,Ying Cheng Zhou,Yi Tang,Yu Fang Chen,Tao Jin
In this paper, Dimethyl sulfoxide (DMSO) was used in the activating process of cotton filter cloth to improve its further hydrophobic modification reaction between cotton fabric and 1-octadecene via an electron transfer (ARGET) atom transfer radical polymerization (ATRP) mechanism. The major influences of DMSO on ARGET-ATRP process was discussed, and meanwhile, the microstructure changes, morphology feature and performance characteristics of cotton filter cloth during the reaction was explored by the SEM, AFM, EDS, XRD and TGA techniques.The result shows that DMSO can leads to cotton fibers adhesion and surface roughening under the ARGET-ATRP grafting reaction conditions, but has little changes on the crystal form, crystallinity and thermal properties of cellulose. At a DMSO dosage of 10%, the hydrophobically modified cotton filter cloth has a water contact angle (CA) of up to 141°. While naturally placed for 1 hour, the CA of hydrophobically modified cotton filter cloth can be stable at 116° with a decay rate of 17.5%, which proves that the hydrophobic stability of cotton filter cloth has been improved markedly. Furthermore, a better improvement for the hydrophobic stability of cotton filter cloth will significantly enhance the application of hydrophobic functional modified cellulosic materials.
Hydrophobic modification of cellulose via activation synergistic activators regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP) method has been proved to effectively improve the long-term hydrophobic stability of cotton filter fabric. However, the extra activation process will inevitably increase the complexity of the reaction process. In this work, carbon disulfide (CS 2 ) was incorporated into the ARGET-ATRP reaction system to avoid adding redundant reaction links. Specifically, the activation and acyl bromination processes were combined, and then the graft modification reaction between the acyl bromide cotton filter fabric and 1-octadecene (1-Oct) was realized by the ARGET-ATRP. The effect of the combined process on the hydrophobic modification reaction and performance of cotton filter fabric was investigated. The results showed that, under the optimum dosages of activator CS 2 , acyl bromide reagent BiB and monomer 1-Oct, the activator CS 2 was directly incorporated into the acyl bromination process. And after ARGET-ATRP Hydrophobic modification, the initial water contact angle (CA) of the obtained hydrophobically modified cotton filter fabric reached 145.0°, the residual contact angle (RCA) after the water droplet retention time of 210 min could still arrive at 125.4°, showing a corresponding attenuation rate (Dr) of 13.5%, which suggested excellent hydrophobicity and durability. Notably, the hydrophobically modified cotton filter fabric also exhibited excellent resistance to chemical corrosion, abrasion resistance and ultrasonic stripping resistance. Furthermore, this hydrophobically modified filter fabric can efficiently separate different types of oil–water mixtures. Even after 12 cycles of oil–water separation process, the separation efficiency still exceeded 95%, and the CA of the modified filter fabric before and after separation was basically unchanged.