The Study Of Interactions Between Alkyl Hydroxyethylcellulose And Surfactant

Hydrophobically modified water-soluble macromolecules,also known as associative macromolecules,are widely used in chemical,pharmaceutical,oil and other fields.They are often co-exist with surfactants for applications.It is the prerequisite of its effective use for in-depth understanding of the interaction with hydrophobically modified water-soluble macromolecules and surfactants.Due to the hydrophobically modified water-soluble macromolecules containing a hydrophobic side chain,when interacting with the surfactant,they exhibit unique behavior combine with common macromolecules.On the other hand,the surfactant with properties of self-organization,can form different aggregates under different conditions.Therefore,it is a special and important role in the form for interaction between the unit of the surfactant aggregates and the hydrophobically modified macromolecule.In this thesis,we used 5-methyl-sodium salicylate(5mS)and 3-hydroxy-2-naphthoic acid(HNC)to regulate the mixed system,which composed by aggregates with different morphologies that the surfactant of cetyltrimethylammonium bromide(CTAB)forming and hydrophobically modified hydroxyethyl cellulose(HMHEC).We revealed the interaction of surfactant aggregates and hydrophobically modified macromolecules,by measuring the macro rheological behavior of the system to reflect the changes in the internal structure of the system.The main work and results are as follows:1.A series of HMHEC with different degree of substitution are synthesized.The solubility and rheological properties of HMHEC are investigated.Found that HMHEC solubility in water and its rheological properties are strongly influenced by the degree of substitution with the alkyl side chain.1.2mol%of HMHEC are determined as the macromolecular component of the mixed system after screening.2.The effects of HMHEC aqueous solutions on the rheological properties with the introduction of CTAB are investigated.The results show that CTAB can only form spherical micelles in the range of the investigated concentration.The presence or absence of micelles and the changes in the number of micelles are mainly decided by the changes of CTAB concentration.Thereby the concentration of CTAB can affect the changes with the network structure of the system,and thus exhibit different rheological behavior.3.The effects of HMHEC/CTAB aqueous solutions on the rheological properties with the introduction of 5mS are investigated.The results show that aggregates change to the morphology with the reduced curvature,because of the 5mS participating in the formation of CTAB micelles,namely spherical micelles-wormlike micelles-vesicles.The role of forms with different aggregates and macromolecules are different,meanwhile the number of aggregates is changing.These two factors affect the network structure that is present within the system or not and the nature of network structure,thus showing different rheological behavior.4.The effects of HMHEC/CTAB aqueous solutions on the rheological properties with the introduction of HNC are investigated.The results show that HNC has played a similar role with 5mS to regulate the morphology of CTAB aggregates and the rheological properties of HMHEC/CTAB mixed aqueous solution.Compared with 5mS,HNC has a stronger regulation.5.The effect of the rheological properties of the mixed aqueous solution with HMHEC/CTAB/5mS and HMHEC/CTAB/HNC by the changes of the concentration of CTAB and HMHEC are investigated.The results show that these two factors have a greater impact on the rheological properties of the mixed system within a certain range.