Preparation, Structure And Properties Of Cellulose Based Resin Composite Films

In this work, cellulose was set as the main subject, which was dissolved to makeregenerated cellulose fims (RC) by green “low-temperature dissolving” approach. Byimpregnation and curing, cellulose based resin compsite films were prepared, and furtherstudies were carried out by learning its structure and properties. The whole paper includesthree main parts.1. Preparation and studies of epoxy resin (EP)/cellulose composite filmsRC films were prepared in LiOH/urea solution under lower temperature. Afterreplacement of the solvent in RC films, RC films were immersed in EP/acetone solution.Followed by thermal-curing, RC/EP films were prepared. We studied the effect ofconcentration of EP/acetone solution on the properties of RC/EP films. The structure andproperties of the composites were studied by infrared, UV light transmittance, SEM, waterabsorption, porosity, cross-linking degree, contact angle and mechanical properties. With theincreasement of EP content in RC/EP composite films, the cross-linking degree, waterresistance, contact angle and mechanical properties increased, and the water absorptiondecreased, while little effect made on the transparency of RC/EP composite films. Meanwhile,we studied the effect of the concentration of cellulose. In the meanwhite, it was found that thethe difference of cellulose concentration had little effect on the properties of composite films.2. Preparation and studies of epoxy acrylic resin (EA)/cellulose composite filmsRC films were prepared in LiOH/urea solution at low temperature. After replacement ofthe solvent in RC films, films were immersed in EA/acetone solution. Followed by ultravioletcuring (UV-curing), RC/EAfilms were prepared. We studied the effect of the concentration ofEA/acetone solution on the properties of RC/EA films. The structure and properties of thecomposite films were studied by infrared, UV light transmittance, SEM, water absorption,porosity, cross-linking degree, contact angle and mechanical properties. The results showedthat: with the content of EA in RC/EA composite films, the cross-linking degree growed, thehydrophobicity and water ressitance increased, while high transmittance remained, thetransmittance at550nm higher than87%with resin content varied between0wt%-70wt%.After curing, EA generated long hydrophobic chain, resulting in the micro phase separationbetween resin and cellulose, which has an effect on the mechanical properties and thermalstability of composite films.3. Preparation and studies of polyurethane acrylate resin (PUA)/cellulose composite filmsRC films were prepared in LiOH/urea solution at low temperature. After replacement ofthe solvent in RC films, the films were immersed in EA/acetone solution. Followed byUV-curing, RC/EA composite films were prepared. We studied the effect of the concentrationof EA/acetone solution on the properties of RC/EA films. The properties of the compositeswere studied by infrared, UV light transmittance, SEM, water absorption, porosity,cross-linking degree, contact angle and mechanical properties. The results showed that: withthe increase of PUA content in RC/PUA composite films, cross-linking density growed,hydrophobic and water resistance increased, maining a high transparency. The aliphatic polyurethane is a kind of flexible polymer. And RC/PUA got an increase in the elongation atbreak with the increase content of PUA resin in composite films, while the tensile stress andYoung′s modulus decreased. But the toughness increased, which may result from theinteraction between cellulose and PUAresin.In summary, this work prepared cellulose based resin composite films by imgregationand curing, two curing methods and three kind of resin were studied, which broden the fieldof the application of cellulose, and provide a new way for the development of cellulosecomposite films..