| Natural polymer,having a series of characters like: wide geographical distribution,abundant resources,renewable,non-toxic,pollution-free etc,is widely used as an alternative material for petrochemical products.However,in the practical application process,the natural polymer couldn't meet the multifunctional needs of various modern materials for the fine structure,texture,variety as well as functionality due to its limited types and relatively simple chemical structures.In practical application process,the chemical and physical blending graft-modified field of polymer modification are the simple & effective way to develop new materials and the main method for preparing a polymer alloy.Through summarizing the progress in both domestic and abroad research that adopted the latex compounding method in the preparation of natural composites in recent years and comparing the differences between the emulsion prepared blending methods and conventional mechanical blending method of natural composites in manufacturing processes,the dispersion of the filler,and mechanical properties aspects,all the research indicated that the latex compounding method has its advantages on the preparation of composite material[1].This paper is studying on the composite emulsion which combined the Konjac glucomannan(KGM)with the Ethyl Cellulose(EC),with blending-centrifugation-visual observation methods,analyzing its phase behaviors,establishing the phase diagram,obtaining the homogeneous phase KGM / EC composite film-forming emulsion,with a high speed centrifugal method compared the film forming emulsion stability(ES)in different ratios of freshly prepared KGM / EC emulsion.using confocal laser(CLSM)micrographs of different ratios of KGM / EC homogeneous film-forming emulsion at different storage days(0d,3d,6d)and particle size distribution of the micro-phase structure variation to study its storage stability and analyze its influencing factors.Adopting a rotational rheometer to test different ratios freshly prepared KGM / EC homogeneous shear flow behavior,activation energy,linear viscoelastic stress(strain),small amplitude dynamic frequency and temperature characteristics,the phase behavior and rheological characteristics of the KGM/EC emulsions will be offer some informations for the material design and structural performance of blending film.The main research results as follows:(1)Taking the composite emulsion which combined the KGM with EC,taking a series ways of blending(600rpm)-Emulsion(10000rpm)-centrifugation(1800rpm)-standing(2h)-visual iamge to observe whether there have a phase-separation,established phase diagram of blend emulsion.With the variation of KGM / EC,the composite emulsion presents three different phase behaviors: two phases separation zone and one phase compatibility area.(2)Selecting the different ratios of KGM / EC filming emulsion in compatibility ares to study its homogenous phase emulsion stability(ES).By contrasting different emulsion stability,the result revealed that in the mixed emulsion systems,the KGM / EC with higher ratio,the emulsion stability(ES)is better when the emulsion solids content reaches a certain value.While the matching has an relatively insignificant influence on emulsion stability(ES)when the emulsion KGM concentration with fixed ratio.(3)Particle size measurement and laser confocal(CLSM)micrographs studied the different ratios of KGM / EC homogeneous phase emulsion at different storage days(0d,3d,6d)of particle phase and micro structural changes,and found that all the film-forming emulsion samples during storage size and micro-phase structure have undergone some degree of change,which presented an unstable phase behavior of the film-forming emulsion in the storage process.Through the comparison,we could found that in KGM / EC filming mixed emulsion systems,the KGM / EC is with higher ratio,the smaller changes occur when the emulsion solids content is fixed.If the the KGM is fixed,the matching is higher,the storage stability fluctuates larger,but the degree of change is relatively smaller.(4)Using a rotational rheometer to test KGM different ratios freshly prepared / EC homogeneous shear flow with milk,viscous flow activation energy,linear viscoelastic stress(strain),small amplitude dynamic frequency and temperature dependence.This study found that all KGM / EC filming emulsion samples exhibit pseudoplastic flow behavior of shear thinning,when constant emulsion solids content is fixed,the KGM / EC is with higher ratio,the pseudoplastic behavior is more obvious,while the matching has little effect on emulsion flow behavior when the ratio of KGM is fixed.The viscous flow activation energy testing found that all KGM / EC filming emulsion viscosity decreases with increasing temperature.When the smulsion solids content reaches a certain value,the ratio of KGM / EC s higher,the activation energy En if greater and the changes of viscosity decreases with temperature is also more significant;while the emulsion viscosity and activation energy show.Stress(strain)scanning showed insignificant changes when the ratio of KGM is settled.Stress(strain)scan showed an emulsion sample linear viscoelastic region between 0.1 ~ 100 Pa.Slight concussion frequency and temperature scans indicate that in KGM / EC filming emulsion,the KGM plays an important role on the viscoelastic properties of the material.Its viscoelastic characteristics change for the frequency change can be attributed to low frequency systems have enough time to molecular entanglement go unwrapping,while in the high frequency area the molecular system able to resist tangles due to limited unwrapping time.In terms of its viscoelastic change in a low temperature,the intermolecular form a temporary network structure,while the thermal motion of molecules damaged the temporary network structure when the temperature rises,so the viscous dominates the emulsion performance. |
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