Aromatic-rich Cellulose-based Polymer For Adsorption Separation Of Acetophenone And 1-phenylethanol

Propylene oxide and styrene co-production technology(abbrev.,PO/SM process)is an important production process for petrochemical production of propylene oxide/styrene monomers.During the process of PO/SM,it can produce large scale of by-product,mainly containing acetophenone(AP)and 1-pH enylethanol(PE).Therefore,recovering purified AP and PE from the by-product as valuable chemical raw materials in the:fine chemical and pharmaceutical industries is meaningful.In this study,aromatic-rich cellulose-based polymer was applied to the adsorptive separation of AP and PE The main research contents are summarized,as can be seen in the follows:(1)Four cellulose-urethane polymers(ACUP,ACUP1/2,ACUP1/3,NACUP)were fabricated by cellulose with isocyanate crosslinker of different phenyl content.Competitive adsorption studies the effects of phenyl content on the adsorption and separation performance of ACUP in binary-solute,ACUP as the best adsorbent is selected.ACUP was confirmed by the instrumental analyses,e.g.,FTIR,XPS,and XRD,etc.Then,a series of adsorption experiments were systematically investigated.The results indicated that adsorption kinetics fitted well with pseudo-second-order kinetics model at different initial concentrations.The Freundlich isotherm model was well fitted to the adsorption process,and the overall adsorption process was exothermal and spontaneous in nature.On binary-solute,recycle adsorption and continuous adsorption-desorption indicated high separation ability and regeneration efficiency of ACUP.Finally,the adsorption mechanism of AP and PE on ACUP was analyzed by theoretical calculation and instrumental analysis.The main adsorption driven force is the weak interaction(π-π and hydrogen bond,etc.).(2)The cellulose nanofibers(CNF)were prepared by TEMPO-mediated oxidation method,and then we synthesized CNF-St through graft copolymerization.Preparation of the porous hyper-cross-linked resins polymer(CNF-St-HCP)was used CNF-St as the aromatic matrix.The cellulose-based polymers were characterized by FTIR,SEM and N2 adsorption-desorption.We found out the best adsorbent under the optimized preparation of conditions and competitive adsorption.Then,a batch of experiments were conducted to investigate the behavior of AP and PE onto CNF-St-HCP.The results show that the morphology is porous with rich pore structure.Then the adsorption capacities for AP and PE and selectivity for AP of cellulose-based polymers were compared though binary-component adsorption experiments.The resuts show that the pore structure of the adsorbent also contributes greatly to adsorption performance besides the intermolecular weak interactions(π-πinteraction,hydrogen bonding,etc.).The results indicated that the adsorption of AP and PE on CNF-St-HCP attained equilibrium within 7 and 10 min,respectively.The adsorption kinetics and isotherms in single solute system were described well with the pseudo-second-order kinetic model and Freundlich isotherm model,while the maximum adsorption capacity for AP and PE were 4.04 and 2.10 mmol g-1 at 15℃.Adsorption capacity in binary-solute for AP and PE were 2.71 and 1.40 mmol·g-1,and selectivity is 4.02.(3)Nine rich-π-modified hyper-cross-linked resins polymer were fabricated by CNF-St-HCP with different crosslinkers.The rich-π-modified CNF-St-HCP were characterized by FTIR and SEM,and compared though binary-component adsorption experiments.The results show that the rich-π-modified CNF-St-HCP adsorption capacity and selectivity are all reduced,because the cave structure is blocked.In summary,we constructed aromatic-rich cellulose-based polymer for the adsorption separation of AP and PE.The results provided theoretical basis for recovery of purified AP from petrochemical effluent,and provided a new idea for dealing with petrochemical by-products and waste.