Preparation And Compatibilization Modiifcation Of Water Swelling Rubber

Hydrophilic component (SAR) and a variety of rubber additives wereadd in the rubber matrix to preparation water-swelling rubber (WSR) by theway of mixing and vulcanization。The characteristics of the two maincomponents of WSR determines it not only have the characteristics of highelasticity and high strength, but also has the characteristics of absorbent rapidexpansion. WSR is widely used as sealing waterproofing stop leakagematerials of oil field, and all kinds of engineering distortion seam,construction seam, and pipe joints, etc.The preparation of the WSR mainly include physical blend and chemicalgraft two kinds of method, but, considered the chemical graftcopolymerization exist a series of problems as high cost low inflation rate andprocess complex, etc. in general,take physical blending method. But becausethe rubber matrix and SAR have a lot of differences in structure and nature,lead SAR widespread exist a lot of problem as poor dispersion, easy to knotgroups and precipitation largely after a period of time, etc. Affected the waterswelling and mechanical properties of the WSR seriously, reduce thelong-term water retention and reuse of the WSR greatly.In order to improve the dispersion of the SAR in the rubber matrix,reducing the shedding of the absorbent material, to improve thewater-swelling properties and mechanical properties of the WSR.In this thesis, PU was prepared by two methods. One, bulkpolymerization. Polyethylene glycol (PEG) and toluene diisocyanate (TDI)asraw materials, hydroxyl-terminated liquid rubber and hydroxyl-terminatedpoly butadiene as capping agent respectively. prepared polyurethane (PU)under conditions of normal pressure and nitrogen atmosphere, and thereaction process in a variety of process parameters are discussed in detail,atlast, detected the hydrophilic and hydrophobic groups with infrared analysis(FT-IR). Two, solution polymerization. Polyethylene glycol (PEG) and toluene diisocyanate (TDI)as raw materials, hydrophilic polyurethaneprepolymer was prepared at first, and then PU were obtained by joining cetylalcohol as hydrophobic segments. Compared two different preparationmethods, we found that, the reaction conditions of solution polymerization arenot as harsh as bulk polymerization’s, the reaction of solution polymerizationare easier to control.Water swelling rubber (WSR) was produced using the NBR and SAR asthe raw materials,the PU as compatibilizer,the white charcoal black asreinforcing agent by the way of physical mix. The influence on themechanical properties and swelling properties of WSR of different PU,whichproduced by different molecular weight PEG and TDI，the dosage of PU, theamount of SAR and the ratio of carbon black/silica were studied. Andanalysis the microstructure of WSR by means of SEM. The results showedthat:1,Compared with carbon black，silica is more conducive to improvingthe water absorption rate of WSR;2, The join of PU significantly reduces theamount of precipitation of SAR and increased the amount of water absorptionof adsorption equilibrium, but, the synthetic conditions of PU should bestrictly controlled,such as dehydration of PEG,Adding speed of TDI,reactiontemperature of PEG and TDI, and the dosage of PU in blends,etc;3, SAR isnot add more water absorption is better, When the dosage of SAR is morethan50phr, the balance water absorption showing a downward trend.