Synthesis Of Blocked Water-based Isocyanate Surfactant And Application On Paper Surface Sizing

As the requirements for paper use continue to increase,specialty papers are receiving more and more attention,and higher requirements are placed on their functionalization.However,the surface sizing system with polyvinyl alcohol as the main sizing agent has not been able to completely solve these problems for the problems of folding resistance and tear resistance that are prone to occur in special paper.In this paper,the graft polymer P(OEGMA-BMA)was synthesized using methoxypolyethylene glycol methyl acrylate(MPEG350MA)and butyl methacrylate(BMA)as raw materials,and infrared,nuclear magnetic analyzer,etc.The structure was discussed,and a series of related equipment such as infrared spectrometer was used to test it and the self-assembly behavior and temperature sensitivity of the surfactant were discussed;The acrylate copolymer P(OEGMA-co-BMA)was synthesized using methoxypolyethylene glycol methyl acrylate(MPEG350MA)and butyl methacrylate(BMA)as raw materials and emulsified 1,6-hexanediisocyanate tri(HDIT),to explore its ability to emulsify trimer and its performance as a sizing agent under different molar ratios of hydrophilic and hydrophobic monomers,use infrared,nuclear magnetic and other equipment to characterize its structure,use particle size analyzer,stability Research on the emulsifying ability of the instrument and other equipment;Using methoxypolyethylene glycol(MPEG),1,6-hexanediisocyanate trimer(HDIT)and methyl ethyl ketoxime(MEKO)as raw materials,a closed-type water-based isocyanate surfactant was synthesized with polyvinyl alcohol(PVA1799)Compounding,under the different surface sizing process,we focused on the improvement of paper strength,toughness and machine washing resistance of the sizing system.The main work and results are as follows:(1)Synthesize graft polymer P(OEGMA-BMA)and discuss its self-assembly behavior and temperature sensitivity:Atom transfer radical polymerization(ATRP)was used to synthesize polymer P(OEGMA-BMA)with different monomer molar ratios.As the proportion of hydrophilic monomer OEGMA increases,the molecular weight distribution becomes wider and more dispersed.It was confirmed that P(OEGMA-BMA)formed core-shell micelles with OEGMA as shell and BMA as core in aqueous solution.The CMC of P(OEGMA-BMA)measured by pyrene fluorescence emission spectroscopy increases with the increase of OEGMA content.When the concentration of P(OEGMA-BMA)solution is greater than CMC,the surface tension of the copolymer hardly follows P(OEGMA-BMA).The concentration of changes,and the LCST value of the polymer P(OEGMA-BMA)aqueous solution increases with the increase of the amount of monomer.(2)Synthesize P(MPEGMA-co-BMA)to emulsify HDIT and study its performance as a sizing agent:The surface tension of P(MPEGMA-co-BMA-3)was 0.77 when the ratio of hydrophilic and hydrophobic monomers(m(MPEGMA):m(BMA))was 3:1 in P(MPEGMA-co-BMA)g/L.The average particle size of the LHAHT-3 dispersion was 147.70nm,the PDI index was 0.143,the TSI was 0.58,and the pot life at 60℃ was 6.5h.When LHAHT-3 dispersion with 10%mass fraction and 10%polyvinyl alcohol(PVA1799)are combined into a sizing solution to sizing the wood pulp base paper,the folding resistance can reach 128 times and the tensile strength The index reaches 55.32Nm/g,the paper sizing degree reaches 26s,and the contact angle between paper and water reaches 110.49°.After sizing with LHAHT-3 dispersion,the sizing agent cross-links the hydroxyl groups on the fiber surface to form a uniform protective film,reducing the gap between the paper fibers,making the paper surface fibers densely combined,and significantly improving the paper’s mechanical properties and resistance Water-based.(3)Synthesize the end-capping copolymer MPEG-HDIT-MEKO and study its performance as a sizing agent:The end-cap copolymer MPEG-HDIT-MEKO has been tested by infrared and molecular weight to confirm its successful synthesis and stability.The unsealing temperature was about 80℃,the average particle size was about 79.82nm,the PDI index was 0.112,and the TSI index was 0.65.After the end-block copolymer MPEG-HDIT-MEKO was unsealed and compounded with PVA1799 as a sizing agent to sizing special paper,the paper’s fold resistance times can reach 3414 times,the amount of glue hanging was 2.5914,the tensile index was 47.13,tearing The index of 7.17 and the stiffness of 81.46 had been greatly improved.