The Syntheses And The Absorbing Power Of Water-Retaining Agent Cross-Linked By Ultraviolet Radiation

In this paper, we have synthesized a kind of new water-retaining agent which has the higher mechanical strength. Firstly, a sort of prepolymer (hydrophilic photocuring resin) was obtained from polyethylene glycol, toluene diisocyanate and hydroxyl acrylate by solution polymerisation in toluene, which contains active double bonds on both ends of the carbon chain. Five systems of PEG2000, PEG4000,PEG6000,TDI and MDI were investigated. In addition, the effect of reaction time,reaction temperature and the mol ratio of reaction monomer on the ability of hydrophilic photocuring resin was investigated also. The results showed: The best prepolymer was obtained from PEG4000,TDI and hydroxyl acrylate by solution polymerisation in toluene at 55/85 when the reaction time was 4/2h.Then ,the granular gel was formed by adding the mixture obtained by mixing the resin with sodium alginate solution and photoinitiator to CaCl2 solution. In the end, the water-retaining agent was obtained under the radiation of ultraviolet light. The effect of the amount of prepolymer, diphenyl ketone, triethylamine, sodium alginate, deionized water and exposure time on the water-absorptivity of water-retaining agent was investigated. The best compounding and radiation condition of ultraviolet light were obtained. At the same time, the effect of temperature and time on the water-discharging of water-retaining agent was investigated. And the effect of exposure time on the salt-absorptivity (0.9%NaCl) and alcohol-absorptivity (methanol,ethanol,propanol,glycol,propanetriol) of water-retaining agent was investigated also. Finally,the use properties of water-retaining agent were studied. Water-holding capacity of the soil was improved when mixing the water-retaining agent with the soil.