Study On Synthesis Of Acrylate-based Copolymers,Preparation Of Composite Coatings And Their Anti-fogging Properties

Polyethylene is a commonly used material for the preparation of greenhouse film.Polyethylene film has various of advantages such as softness,dustproof,safe,non-toxic,light texture and good light transmission,etc.One of the problems that polyethylene film face is its non-satisfactory anti-fogging performance.Acrylate-based copolymer is a commonly used material for anti-fogging purpose.In this thesis,acrylate-based copolymers were prepared,their structures were characterized,and anti-fogging properties of polyethylene films coated with copolymers were studied.(1)Five groups of copolymers P(AA-co-PEGMA)s were prepared by free radical polymerization using acrylic acid(AA)and methacrylate polyethylene glycol methacrylate(PEGMA)as comonomers.The copolymers were characterized by 1H-NMR,FT-IR,TG and DSC and the test results of the five groups of copolymers were compared.The anti-fogging films were prepared by coating copolymer solutions on the surface of the polyethylene films with a glass bar.WCA was used to study the hydrophilic properties of the anti-fogging films.UV-vis was used to study the light transmittance of the anti-fogging films.SEM and AFM were used to study the surface morphology.The anti-fogging performance of the films was tested on an anti-fogging performance tester.Copolymer solutions were blended with T-80 at different mass fractions to obtain composite coating solutions.The composite solutions were coated on the surface of the polyethylene films to produce composite anti-fogging films and the properties of films were studied.It was found that the unit ratios(AA:PEGMA)in copolymers were 1:0.520,1:0.275,1:0.127,1:0.051 and 1:0.042,respectively.After coated with copolymer solutions,the hydrophilicity and light transmittance of polyethylene films were improved and the surface roughness was decreased.The original drop time of anti-fogging films was firstly decreased and then increased by increasing the amount of PEGMA in coatings while ten drops time and duration of the films were decreased.Moreover,for P(AA-co-PEGMA)/T-80 composite coatings,the original drop time of the films was firstly decreased and then increased while the ten drops time decreased by increasing the amount of T-80 added in composite coatings.The duration of the films was firstly increased and then decreased by increasing the amount of T-80.The original drop time was reached at the minimum value whereas the duration was reached at the maximum as the amount of T-80 added was 6 w/v%.(2)Five groups of copolymers P(AA-co-BMA)s with different unit ratios(AA:BMA)were obtained by free radical polymerization using acrylic acid(AA)and butyl methacrylate(BMA)as comonomers.The copolymers were characterized by 1H-NMR,FT-IR,TG and DSC.The copolymer solutions were coated on the surface of polyethylene films by a glass rod to form copolymer anti-fogging films.WCA was used to study the hydrophilic properties of anti-fogging films.UV-vis was used to study the light transmittance of anti-fogging films.SEM and AFM were used to study the surface morphology.The anti-fogging performance of the films was tested on an anti-fogging performance tester.Copolymer solutions were blended with T-80 surfactant at different mass fractions to obtain composite coating solutions.The composite coating solutions were coated on the surface of the polyethylene films by glass bar scraping method and the properties of coated films were studied.It was found that the unit ratios(AA:BMA)in copolymers were 1:0.400,1:0.305,1:0.259,1:0.238 and 1:0.198,respectively.The hydrophilicity and light transmittance of the coated films were higher as compared to the uncoated films and the surface roughness was lower.The anti-fogging results showed that when the proportion of AA in coatings was increased,the original drop time,ten drops time and duration of films were decreased.for P(AA-co-BMA)/T-80 composite coatings,the original drop time of the films was firstly decreased and then increased while the ten drops time decreased by increasing the content of T-80.The duration of anti-fogging films was firstly increased and then decreased by increasing the content of T-80.Considering the anti-fogging duration and anti-fogging performance of the films,the optimal addition amount of T-80 came out to be 6 w/v%(3)Two groups of copolymers were synthesized by using N,N-methylenebisacry-lamide(NMBA)as a crosslinking agent.The first series of copolymers P(AA-co-PEGMA-co-NMBA)s were prepared using AA,PEGMA and NMBA as comonomers whereas the second series of copolymers P(AA-co-BMA-co-NMBA)s were prepared using AA,BMA and NMBA.The amount of NMBA added was controlled at 1-5 mol‰.The thermal properties of the copolymers were studied by TG and DSC.The copolymer solutions were coated on the surface of polyethylene films by a glass rod to form copolymer antifogging films.WCA was used to study the hydrophilic properties of anti-fogging films.UV-vis was used to study the light transmittance of anti-fogging films.The anti-fogging performance of the coated films was tested on an anti-fogging performance tester.Also,copolymer solutions were blended with T-80 surfactant at different mass fractions to obtain composite coating solutions.The composite solutions were coated on the surface of the polyethylene films by glass bar scraping method and the properties of coated films were studied.The hydrophilic properties of coated films were decreased whereas the light transmittance decreased slightly when the amount of added NMBA was increased.The anti-fogging results showed that the original drop time,ten drops time and the duration of anti-fogging films were increased when the amount of NMBA was increased.By comparing the change of the original drop time and the ten drops time with the anti-fogging duration,the optimal addition amount of NMBA was 3 mol‰.For P(AA-co-BMA-co-NMBA)/T-80 and P(AA-co-PEGMA-co-NMBA)/T-80 compo-site coatings,the anti-fogging performance of the films was tested.The original drop time of the films was firstly decreased and then increased while the ten drops time was decreased by increasing the amount of T-80.The duration of anti-fogging films was firstly increased and then decreased by increasing the amount of T-80.