Study On The Modification Of Cation PU,The Preparation Of CaCO₃/PU Compositite Material,Study On The Surface Activity Of Partically Saponified SUE And Application

PU coating is a kind of upscaled coating.Waterbomed.PU is studied widelybecause of the increase of environmental protection consciousness. There are manyreports about the preparation and research of anion PU and its modification.However,there are still few reports about cation PU and the grafting modification of PUwith acrylate have not appeared so far.In this dissertation ,firstly, Stable cationic waterbome polyurethane emulsion wassynthesized via the reaction of polyether polyols, isophorone diisocyanate (IPDI) andN-methydiethanolamine (MDEA) with dibutytin dilaurate (DBTL) as catalyst. Theeffects of the ratio of -NCO to -OH, hydrophilic chain-extending agent (MDEA) andneutrulization degree on the stability of cationic polyurethane emulsion were discussed.Zeta electric potential and granularity were tested by Electric Potential Meter and theoptimum conditions were obtained.Secondly, PU pre-polymer was modified by acrylate monomers using twomethods.The first,PU emulsion with no saturated duplet bond was prepared. Thenacrylate monomers were added to PU emulsion to prepare PUA IPN network. Thesecond,PU pre-polymer with no saturated duplet bond was prepared and then acrylatemonomers were added to it. Through neutrulization,the modified emulsion wasobtained.The second method was confirmed to be a better way. The effects of amountof acrylate monomers, the type of blocking agents,content of HEMA, content of TEM,proportion of solvent on the modified emulsion were investigated.The samples werecharactered by TEM,FTIR,DSC,Viscometer.It was comfirmed that an ideal preparationmethod for acrylate-modified cationic polyuthane emulsion was found and modifiedemulsion with good stability, high hardness of film and good water-resistance wasobtained when the ratio of PU to acrylate is 2:1,the content of HEMA is 3ï¼…and thecontent of TMP is 1ï¼…,et al. Calcium carbonate is a kind of very important inorganic padding using widely inthe domain of plastic,rubber, coating and papermaking. But the bad dispersivity insubstrate limited its use. Preparation of CaCO₃ compositite material via in-situprecipitation is a good method to solve above problems.Amphilic copolymer P(TDI-DMPA)(abbre. PU) with carboxy group wassynthesized using TDI and DMPA as monomers.Using PU as Superficial modifiedagent, CaCO₃ aggregate with different morphologies were prepared in the system. Itwas confirmed that PU displayed major function in forming process of CaCO₃. Thisarticle also found that CaCO₃ did not separate out of the system and Precipite on PUmolecular chain in certain range.This is the foundation of our next work.The organic-inorganic composite CaCO₃/PU was prepared via a in-situprecipitation method. The reaction mechanism of the CaCO₃/PU compositite filmmaterial was discussed. The effect of the proportion of mixed solvent,conent ofCa(OH)₂,reaction tenperature on morphology and hardness of compositite film wasdiscussed. When the concentration of PU was 80 g/L and the loading concentration ofCaCO₃ was 4×10^-2 mol/L, the CaCO₃ particles in the as-obtained film were of uniformsize and good dispersion. XRD was carried out to determine the crystal structure of thecalcium carbonate. It was revealed by IR analysis that the interaction of PU and CaCO₃in the composite was chemical adsorption and coordination. This method can greatlyimprove the joining intensity of CaCO₃ and PU,which provides a good idea for thepreparation of inorganic/organic composites. Sodium undecenoate is a polymerisable surfactant with a double bond in the endof its molecular chain, which can be used as reactive emulsifier in preparing coatings.In this artile, the phase diagrams of pseudo-tricomponent about the system ofundecycenic acid-sodium undecylenate-H₂O have been studied, indicating that a widerange of liqid crystal phase can be formed in this system. On the basis of this propety,an appropriate proportion of undecycenic acid to sodium undecylenate which can formliqid crystal phase are used and their mixture with surfactant OP-10 is employed asemulsifier to investigate the solubilization to styrene and BA (1:1, m/m). Furthermore,the mechanism of solubilization is also discussed. Using a proper proportion ofundecycenic acid and sodium undecylenate with highest solubilization amount asemulsifier, the mixture of styrene and BA as monomer, the emulsion polymerization iscarried out trying to prepare emulsion with high solid content by controlling thedropping speed of monomers, stirring speed and temperature, etc.The effect of emulsifier amount used, reaction temperature, saponified degree onemulsion size were discussed. It was confirmed that St-BA emulsion with solid contentof 45% was obtained when emulsifier amount is 4%, reaction temperature is 70℃andsaponified degree is 0.8:1.There were anion carboxylic acid groups on the surface of emulsion which can beused to prerare organic-inorganic compound material such as CaCO₃/St-BA compoundmaterial. We can also use it as coating matching with cation PUA to improve the unionintensity on the substrate because of the mutually attracts between the positive andnegative electric charge. All of them can be researched in the future.