Synthesis And Characterization Of2,2-Bis(Hydroxymethyl) Butyric Propyl-3’-sodium Sulfonate And The Polyurethane Dispersions Containing The Sulfonate

In this paper, a new type of hydrophilic sulfonate monomer:2,2-bis(hydroxymethyl)butyric propyl-3’-sodium sulfonate (DMBPS-Na) was synthesized by sulfo alkylation reactionwith2,2–bis(hydroxymethyl)butyric acid(DMBA),1,3-propane sultone(1,3-PS) andsodium hydroxide. Using self-made sodium2,2-bis(hydroxymethyl) butyric propyl-3’-sodiumsulfonate as a hydrophilic monomer, polytetramethylene glycol (PTMG-2000) as softsegments, isophorone diisocyanate (IPDI) and1,4-butanediol (BDO) as hard segments,ethylene dimine (EDA) as amine chain extenders, dibutyltin dilaurate (DBTDL) as catalysts,sulfonate type polyurethane dispersions (PUDs) with solid content about50%weresynthesized by acetone process and prepolymer method.The structure of2,2-bis(hydroxymethyl) butyric propyl-3’-sodium sulfonate wascharacterized by means of FT-IR,1HNMR,13CNMR, elemental analysis and liquidchromatography. The melting point of DMBPS-Na was between85~90℃and DMBPS-Nawas more soluble in water, ethanol and DMAc, slightly soluble in acetone and ethyl acetateethanol. The optimal reaction temperature and reaction time were130℃and2.5hours.PUDs synthesized by acetone process: the value of zeta potentials of PUDs werebetween-45mV and-75mV, the average particle sizes of PUDs were at50~500nm, brookfieldviscosity of PUDs were between100~800mPa·s. TEM analysis showed PUDs particles werespherical shapes with different sizes and PUDs had the good emulsion stability. With increasingDMBPS-Na content, the particle size of PUDs decreased, but the zeta potentials and theviscosity of PUDs increased. The emulsion stability became better and particle sizedistributions became narrower with the increasing of DMBPS-Na content. With increasing hardsegment content, the zeta potentials and the viscosity of PUDs decreased, but the particle sizeincreased. The emulsion stability became worse and particle size distributions became widerwith the increasing of hard segment content.PUDs synthesized by acetone process: the max ultimate elongation of PUDs cast filmwas2500%and the max elongation strength was46.95MPa. The water absorption of PUDswere between1.5%and8%. With increasing hydrophilic group content, the elongation of PUDsfilm and water absorption increased, but the elongation strength and shore A hardnessdecreased. The water resistance of PUDs film became worse with the increasing ofhydrophilic group content. With increasing hard segment content, the elongation of PUDs filmand water absorption decreased, but the water resistance became better. The PUDs films showed phase separation. The thermal stability of PUDs film decreased, but the storagemodulus and loss modulus increased with the increasing of hard segment content. The glasstransition temperatures(Tg) of PUDs cast films were between-43~-68℃and thecold-resistant stability was excellent. Thermogravimetry analysis(TGA) indicated that thedegradation of PUDs cast film started at about270℃and completely degradation at about470℃.PUDs synthesized by prepolymer method: the value of zeta potentials of PUDs weremore than-45mV, the average particle sizes of PUDs were at100~400nm, brookfieldviscosity of PUDs were between100~500mPa·s, water absorption of PUDs film werebetween4%~11%. Compared with PUDs synthesizing by acetone process and in the sameformula: the average particle sizes and water absorption of PUDs synthesizing by prepolymermethod were larger, brookfield viscosity were smaller. The amount of hydrophilic monomerbecame larger and the emulsion stability became worse.