Study On The Forming Proformence Of Modified Collagen

Millions of leather solid wastes with and without chromium are produced annually in the splitting,cutting,grinding and trimming operations.However,the traditional disposal methods will not only engender wasting of resources,but also heavily pollute the environment.Actually,those wastes are rich in abundant collagens but collagen has a good water solubility,poor surface activity and weak foamability,after proper treatment,it has certain surface activity and foamability,Thus,the present work used the collagen extracted from leather solid wastes to prepare the collagen foaming agents by grafting modification of the active groups,finally it realized the resource utilization of leather solid wastes and reduced the environment pollution.Firstly,the collagen foaming agent was prepared by the collagen and lauroyl chloride.Foam height,half life and the amino conversion of collagen were taken as index,the reaction temperature,the reaction time,the dosages of lauroyl chloride and collagen on foamability were investigated.The anionic surfactants such as sodium dodecyl benzene sulfonate,sodium dodecyl sulfate,sodium lauryl sulfate,as well as foam stabilizer such as methyl cellulose,triethanolamine,hydroxyethyl cellulose were used on the synergistic effect of collagen foaming agent.The structure of collagen foaming agent were characterized by GPC,IR,XRD,DSC,particle size and isoeletric point,etc.The properties such as solubility,surface activity and emulsification were also studied.Results showed that the optimum synthesis conditions were as follows,the reaction time was 4.5 h,the reaction temperature was 75 ? and the mass ratio of collagen powder and lauroyl chloride was 12.5:1.Under this condition,the amino conversion of the foaming agent produced by the reaction was45.83 %,the foam height was 143.7 mL,and the half life was 30 min.After remixed by the mass ratio of ?(collagen foaming agent): ?(sodium dodecyl sulfate):?(triethanolamine)=5:1.1:0.5.The foam height was more than 400 mL and the half life can reached20 min.GPC and IR results confirmed that collagen foaming agent had theexpected structure.XRD results illustrated that the incorporation of lauroyl can increase the tacticity and crystallinity of the collagen molecular chain segments.The collagen foaming agent had lower isoelectric point,smaller particle size and uniform.Collagen foaming agent can be dissolved in water and ethanol,slightly soluble in methanol and acetone,and insoluble in dichloromethane,petroleum ether,toluene,paraffin and n-butanol.When the CMC of collagen foaming agent reached 1.5 g/L,the surface tension was 39.5 mN/ m,and the collagen foaming agent had better emulsifying ability.After compounding,The surface tension values were decreased by 16.5 mN/m,the viscosity values were increased by315 mPa·s and the emulsifying property and the emulsifying stability of the collagen foaming agent was improved significantly.Secondly,collagen foaming agent was synthesized by collagen and dodecylamine.The reaction temperature,time,catalyst and dodecylamine on the influence of foam height,half-life,carboxyl content were investigated by single factor and orthogonal experiment.The anionic surfactants such as sodium dodecyl benzene sulfonate,sodium dodecyl sulfate,sodium lauryl sulfate,as well as foam stabilizer such as methyl cellulose,triethanolamine,hydroxyethyl cellulose were used on the synergistic effect of collagen foaming agent.The structure of the collagen foaming agent was characterized by GPC,IR,XRD,thermal analyzer and particle size.The physical and chemical properties such as solubility,surface activity and emulsification were studied.The optimum reaction conditions were as follows,the reaction time was 2.5 h,the reaction temperature was 50 ?,the mass ratio of dodecylamine and catalyst was 3:2,under the conditions,the foam height was 181.67 mL,half life was 318 s,carboxyl content was 0.1635.According to the mass ratio of ?(collagen foaming agent):?(sodium dodecyl sulfate): ?(hydroxyethyl cellulose)=6:1.3:1.2,the foam height can be reached512 mL,the half life was about 22 min.The FT-IR and GPC spectra of the diamine modified collagen confirmed that the crosslinking reaction was successfully carried out.The collagen foaming agent could dissolve in water,slightly soluble in n-butanol,methanol,ethanol and acetone,and insoluble in Dichloromethane,petroleum ether,toluene and paraffin.When the CMC reaches1.0 g/L at 25 ?,the surface tension is 19.6 mN/m,and the collagen foaming agent has better emulsifying ability.After compounding,the surface tension wasdecreased by 3.6 mN/m,the viscosity value was increased by350 mPa·s,the emulsion stability has been greatly improved after combination by means of synergistic effect of emulsion stability.Finally,compared with sodium dodecyl sulfate,dodecylamine modified collagen foaming agent had excellent foamability and good foam stability,lauroyl chloride modified collagen foaming agent had a good foamability and excellent foam stability.