Preparation And Properties Of Homogeneous Modification For Cellulose

Cellulose, as a green, low cost, nontoxicity, renewable and biodegradable natural polymer, is one of the most promising biodegradable materials on earth. The effective utilization of the cellulose has a great significance to the crisis of resource. In this study, cellulose was modified homogeneously using an ionic liquid1-butyl-3-methylimidazolium chloride (BMIMC1) as reaction medium.We design work on the following aspects:1、A novel graft copolymer (Cellulose-g-PCL) was prepared homogeneously via grafting ε-caprolactone in BMIMC1by ring open polymerization using Sn(Oct)2as an initiator. The graft copolymers were characterized by means of FTIR, CP/MAS13C-NMR, DSC, TGA, XRD and SEM. Mechanism of s-caprolactone open-loop polymerization initiated with Tin (II) Octoate was discussed. The effects of the purity of feed weight ratio, initiator content ration、reaction time on the graft ratio were investigated systematically. It was showed that the graft copolymer with grafting yield at20%was obtained when the temperature was120℃, reaction time was24h, the contents of initiator was0.5%and the weight ratio of cellulose and s-caprolactone was1:10, respectively.2、The atom transfer radical polymerization was adopted to replace the conventional heating to synthesize the graft copolymer of cellulose with s-caprolactone. Cellulose-based macroinitiator (Cell-ClAc) was first synthesized by direct homogenous acylation of cellulose in BMIMC1in absence of any catalyst. Then the homogeneous ATRP of PCL from cellulose macroinitiator was carried out in BMIMC1. The cellulose macroinitiator and graft copolymers were characterized by means of FTIR, CP/MAS13C-NMR, TGA, XRD and SEM.3、A novel graft copolymer (MCC-g-PCL) was prepared homogeneously via grafting ε-caprolactone in BMIMC1by ring open polymerization using Sn(Oct)2as an initiator. The graft copolymers were characterized by means of FTIR, DSC, TGA, XRD and SEM. The effects of the purity of feed weight ratio, initiator content ration on the graft ratio were investigated systematically. It was showed that the graft copolymer with grafting yield at22%was obtained when the temperature was120℃, reaction time was24h, the contents of initiator was0.5%and the weight ratio of cellulose and ε-caprolactone was1:12, respectively.4、Comprehensive studies on the adsorption properties of the cellulose adsorbents were conducted in ways of static adsorption using metal ions (Cu2+and Ni2+) as adsorbates. The affecting factors of the adsorption including the concentration of metal ions and temperature were researched, the cellulose adsorbents of Cu2+and Ni2+two kinds of metal ions adsorption effect was compared. And isotherm adsorption of Cu2+in different temperatures was also researched. Moreover, the adsorption thermodynamics of Cu2+was explored. The results showed that the cellulose adsorbents had excellent adsorption capacities for metal ions. The results showed that the cellulose adsorbents had excellent adsorption capacities for Cu2+(133mg/g) and Ni2+(40.4mg/g) when at the same adsorption temperature and adsorption time. The static adsorption process of Cu2+follows Langmuir and Freundlich adsorption isotherm equations. From the adsorption thermodynamics Cu2+, it can be concluded that the adsorption process was endothermic.