Preparation Of Nanocrystalline Cellulose From Waste Cotton Materials And Its Reinforcement Research In Nature Rubber

Waste cotton materials mainly compose of cotton fibers. The extraction product-WCNC(waste cotton nanocrystalline cellulose) from waste cotton materials not only equipped with cellulose’ natural properties, such as extensive sources, renewable, degradable and environmentally friendly, but also possess excellent nature, say high modulus and strength, large specific surface area and low density, etc.. WCNC co-reinforcing nature rubber(NR) composites with carbon black(CB) not only can reduce the useage amount of CB, but can gain better performance in some properties than NR filled only with CB. Besides the exploitation of waste cotton materials can also turn wastes into value and relieve environmental pollution.This paper adopted one-step acid hydrolysis to extract WCNC from waste cotton materials. The optimal preparation scheme was explored and determined. The extracted WCNC was rod-like shape, about 40 nm in diameter and 200~600 nm in length. WCNC partially substituted CB to prepare NR/CB/WCNC composites, then compared with 45 phr CB reinforced NR composites’ performance(control sample). Researchs show that WCNC improved the dispersion effect of CB in NR obviously, the processability of NR/CB improved, the optimum cure time shortened, the build-up temperature and permanent compression set decreased. When WCNC replaced CB content to 10~15 phr, the tensile and tear strength of NR/CB/WCNC composites were close to that of 45 phr CB reinforced NR, and the rolling resistance was decreased, Flexible crack resistance was improved. Furthermore, the addition of WCNC effectively boosted NR/CB composites’ degradation properties.To low down the chemical polarity of WCNC surface so as to boost its interaction with NR matrix, this paper utilized KH550 to modify WCNC to prepared modified waste cotton nanocrystalline cellulose(m-WCNC), then NR/CB/m-WCNC composites was prepared by using m-WCNC substituting CB. Result show that the m-WCNC surface’ hydrophobic property was enhanced; the fillers in composites dispersed more homogeneously, the Payne effect weaken obviously. Compare with 45 phr CB reinforced NR composites, the tensile strength, tear strength and wear-resisting propertiesn of NR/CB/WCNC composites were basically matained when WCNC replaced CB’ amount less than 15 phr, first-grade flexible crack performance strengthed, permanent set dropped, meanwhile got more lower value of the rolling resistance and glass transition temperature(Tg)Study results show that bonding agent RH can boost the interface adhesive effect between WCNC and NR, increase the crosslink density and shorten the optimum cure time and improve maximum torque of NR/CB/WCNC composites. When WCNC substituted CB to 20 phr, the NR/CB/WCNC/RH composites can keep nearly the mechanical strength and abrasion resistance of 45 phr CB filled NR composites, in addition, the NR/CB/WCNC/RH can get lower rolling resistance, compression heat bulid-up and compression permanent set, get better thermal decomposition properties as well.