Preparation And Rheological Behaviour Of Hydrophobe-Modified Ethoxylated Urethane Thickener

Latex paint thickener is a kind of rheological which is used to adjust the rheology ofpaints. Its development experienced from the early inorganic thickener tosynthesized organic thickener, and from cellulose to alkali soluble acrylicthickener(ASE) then to polyurethane associative thickener.The growing awarenessof the importance to reduce the emission of volatile organic components（VOC） has madehydrophobically modified ethoxylated polyurethane thickener (HEUR) become a major partof thickeners.For the unique thickening mechanism, HEUR is better at thickening under highshear rate and levelling property.For this reason, HEUR is going to replace the status oftraditional thickeners.This article aims to synthetic polyurethane associative thickener with better thickening.Inthe second chapter, we discussed the process conditions of polyurethane thickenersynthesis.The study that the rate of reaction can be improved by elevating the reactiontemperature effectively, and a small amount of catalystcan can play a significant catalyticeffect, so,we determine that the reaction temperature is80oC and the amount of the catalyst is0.2wt%,and the time of the prepolymerization reaction, the chain extension reaction and thereaction capped reaction is3hours respectively, as the reaction conditions of the synthesis ofthe polyurethane thickener in the present systemoptimization. And we systemically synthesizea series of polyurethane associative thickener with different materials and ratio.Infraredspectroscopy and gel permeation chromatography (GPC) on the structure and molecularweight distribution of synthetic thickeners product are characterized to determine thesynthesized compounds.In the third chapter, the thickening effect of polyurethane thickener is studied in aqueoussystems and in the emulsion system, we find that the polyurethane thickener which wesynthesis in the lab in the aqueous phase and an emulsion have a good thickening effect.Meanwhile, we also test rheological behavior of thickening system by viscoelasticspectrometer, we find that the rheological behavior of experimental synthetic thickeners arevery similar to the standard sample, and the viscosity is more significant than that of sample, therefore, we get a polyurethane associative thickener with better thickening effect than thesample.In the fourth chapter, we introduce the ferrocene to polyurethane systems to observe theimpact of the the ferrocene redox behavior on thickening effect of polyurethane thickener. So,we design a novel ferrocenyl alkyl alcohol molecule (Fc(CH2)10CH2OH) in this chapter,anduse TLC,’H-NMR, FT-IR to determine this compound. We use Fc (CH2)10CH2OH as aterminal blocking agent to synthesize a polyurethane thickener, and study the polyurethanethickener by surface tension, rheology, UV-Vis, redox, electrochemical, cyclodextrin clathratemeans. Surface tension of ferrocene-based polyurethane thickener indicate that the CMC isabout0.05mM; the cyclodextrin inclusion experiments show that the thickening principle ofsynthesized polyurethane thickener is hydrophobic interaction; chemical and electrochemicalredox and rheology show that ferrocene-based thickener has obvious redox reversibility;UV-vis absorption spectrum further indicates that the ferrocene thickener has the reversibleresponse in the redox process. Meanwhile,We also research the thickening effect offerrocenyl thickener in the emulsion, the results show that ferrocene-based thickener whichwe synthesized has good thickening effect.