Preparation Of Star-shaped Cyclodextrin Polymer And Its Adsorption Properties To Organic Dyes Molecules

The widespread use of organic dyes has led to a significant increase in colored wastewater.Due to chemical stability and non-biodegradability,it poses a serious threat to environment and human safety.Therefore,the research and development of new adsorbents for the efficient removal of organic dyes is of great significance in life,and it is directly related to the sustainable development of the environment.Cyclodextyins(CDs)are made up of 6,7,8 or more D-glucopyranose units connected by ?-1,4 glycosidic bonds.Having externally hydropHilic cavity structure,its special structure can contain a variety of small organic compounds such as organic dyes.The hydroxyl group on the edge of the cavity can be modified by different groups to form a variety of cyclodextrin derivatives,changing its pHysical and chemical properties.Star polymers can form three-dimensional structure.A new space characteristic of enclosing guest molecules can be formed between the three-dimensional structures of the arm chains.In this thesis,the advantages of cyclodextrin and star polymers are combined to synthesize a star polymer with cyclodextrin at the end.This polymer is used as an adsorbent to study its effect on organic dyes.Adsorption properties of three dyes such as basic magenta and saffron cyanine T and napHthol green B.Besides,this polymer was bonded to silica gel to form a stationary pHase,and its potential application value was studied,including separation of isomers.The main contents are as follows:First,synthesis of a six-arm star polymer with ?,?,and ?-CD ends.Under vacuum and drying conditions,using stannous isooctanoate as a catalyst and dipentaerythritol as an initiator,?-caprolactone is ring-opened to synthesize six-arm polycaprolactone.Then through the esterification reaction,polycaprolactone and p-aminobenzoic acid are used to synthesize a six-arm star polymer with an aromatic amine terminal.Further more,?,?,?-CD monoaldehyde undergoes an addition-dehydration reaction with them to synthesize a six-arm star polymer with an imine group-linked at ?,?,and ?-CD ends.Second,adsorption properties of six-arm star polymers with ?,? and ?-CD in the ends to organic dyes napHthol green,basic magenta,and saffron red T are explored.Six-arm star polymers of ?,? and ?-CD in the ends are used as adsorbents respectively.The effects of temperature,time,and pH on the adsorption properties of the organic dyes napHthol green B,basic fuchsin,and saffron red T were studied.The results show:A.After 2 hours,1.5 hours,and 2 hours of adsorption,the adsorption capacity of 6As-PCL-PABA-?,?,and ?-CD to basic magenta reaches the maximum value.After 2 hours,2 hours and 2.5 hours,the adsorption capacity of 6As-PCL-PABA-?,?,?-CD to saffron red T reaches the maximum value.After 1.5 hours and 2.5 hours of adsorption,the adsorption amount of napHthol green B reached the maximum value,but 6As-PCL-PABA-?-CD hardly adsorbs napHthol green B.B.Basic conditions are favorable for 6As-PCL-PABA-?,?,?-CD to adsorb basic fuchsin.Neutral conditions are favorable for 6As-PCL-PABA-?-CD to adsorb saffron red T.Alkaline conditions are favorable for 6As-PCL-PABA-?-CD to adsorb saffron red T.Acidic conditions are favorable for 6As-PCL-PABA-?-CD to adsorb saffron red T.Acidic conditions are favorable for 6As-PCL-PABA-?,?-CD adsorbed napHthol green B,while 6As-PCL-PABA-?-CD hardly adsorbs napHthol green B.C.High temperature is good for 6As-PCL-PABA-?,?-CD adsorption of basic magenta.Low temperature is good for 6As-PCL-PABA-?-CD adsorption of basic magenta.High temperature is good for 6As-PCL-PABA-?,?,?-CD adsorption of saffron red T.Moderate temperature is favorable for 6As-PCL-PABA-?-CD adsorption of napHthol green B.High temperature is favorable for 6As-PCL-PABA-?-CD adsorption of napHthol green B,but 6As-PCL-PABA-?-CD hardly adsorbs napHthol green B.