The effect of triethyl citrate(TEC)on the stability of cream preparations containing urea or hydroxyethyl urea along with their moisturizing effect on skin was investigated.The results showed that creams incorporating...The effect of triethyl citrate(TEC)on the stability of cream preparations containing urea or hydroxyethyl urea along with their moisturizing effect on skin was investigated.The results showed that creams incorporating urea or hydroxyethyl urea led to increase in pH value after a long-term and high-temperature storage.pH change in the latter one was relatively smaller.With the addition of TEC,the elevated pH of the formula system was suppressed.In the situation of stable formula,the higher the TEC added,the more significant inhibition effect on the pH change was observed.In the moisture retention test in vivo,compared to 27.19%moisture rate in negative control,cream preparations containing 5%urea or 5%hydroxyethyl urea had remarkable moisturizing effect,which were all higher than 52%.The latter one was relatively more prominent.There is no significant effect on moisturizing effect for product with TEC additive.展开更多
In the research,three kinds composite materials of biomimetic laminated boards made from cross-linking starch/maize stalk fiber-the single layer jute fiber reinforced maize stalk fiber boards,the dual layer jute fiber...In the research,three kinds composite materials of biomimetic laminated boards made from cross-linking starch/maize stalk fiber-the single layer jute fiber reinforced maize stalk fiber boards,the dual layer jute fiber reinforced maize stalk fiber boards,the jute fiber hybrid reinforced maize stalk fiber boards were obtained according to the formulation of cross-linking maize starch adhesive and the preparation process of composite materials.The hygroscopicity variation of the biomimetic laminated boards made from cross-linking starch/maize stalk fiber was investigated under different relative humidity conditions.The moisture absorption rate and the variation velocity were used as important evaluation indexes to evaluate the moisture absorption properties of the straw fiber composites.The mathematical models of the moisture absorption rate and the variation velocity were established.The hygroscopicity variation curves of three kinds of composite materials were measured under the five different relative humidity conditions.The results showed that the three kinds composites had low moisture absorption rate compared with other stalk fiber composites which were good at water resistance and the waterproof property of the three kinds stalk fibers were excellent under the experimental conditions.The research provides a useful reference to improve the water resistance of fiber composites and a new idea on the development and application of the biodegradable composites,especially the straw fiber reinforced composites.展开更多
文摘The effect of triethyl citrate(TEC)on the stability of cream preparations containing urea or hydroxyethyl urea along with their moisturizing effect on skin was investigated.The results showed that creams incorporating urea or hydroxyethyl urea led to increase in pH value after a long-term and high-temperature storage.pH change in the latter one was relatively smaller.With the addition of TEC,the elevated pH of the formula system was suppressed.In the situation of stable formula,the higher the TEC added,the more significant inhibition effect on the pH change was observed.In the moisture retention test in vivo,compared to 27.19%moisture rate in negative control,cream preparations containing 5%urea or 5%hydroxyethyl urea had remarkable moisturizing effect,which were all higher than 52%.The latter one was relatively more prominent.There is no significant effect on moisturizing effect for product with TEC additive.
基金supported by National Science Fund for Distinguished Young Scho lars of China(Grant No.50025516)National Natural Science Foundation of China(Grant No.50675087,50673037,5030600131)+1 种基金"985 Project"of Jilin University,Natural Science Foundation of Henan Educational Committee(Grant No.2009B210006)Innovation Ability Foundation of Natural Science(Grant No.2013ZCX002)of Henan University of Science and Technology.
文摘In the research,three kinds composite materials of biomimetic laminated boards made from cross-linking starch/maize stalk fiber-the single layer jute fiber reinforced maize stalk fiber boards,the dual layer jute fiber reinforced maize stalk fiber boards,the jute fiber hybrid reinforced maize stalk fiber boards were obtained according to the formulation of cross-linking maize starch adhesive and the preparation process of composite materials.The hygroscopicity variation of the biomimetic laminated boards made from cross-linking starch/maize stalk fiber was investigated under different relative humidity conditions.The moisture absorption rate and the variation velocity were used as important evaluation indexes to evaluate the moisture absorption properties of the straw fiber composites.The mathematical models of the moisture absorption rate and the variation velocity were established.The hygroscopicity variation curves of three kinds of composite materials were measured under the five different relative humidity conditions.The results showed that the three kinds composites had low moisture absorption rate compared with other stalk fiber composites which were good at water resistance and the waterproof property of the three kinds stalk fibers were excellent under the experimental conditions.The research provides a useful reference to improve the water resistance of fiber composites and a new idea on the development and application of the biodegradable composites,especially the straw fiber reinforced composites.
