Preparation and properties of emulsifier-/NMP-free crosslinkable waterborne polyurethane-acrylic hybrid emulsions for footwear adhesives (II) – effect of dimethylol propionic acid (DMPA)/pentaerylthritol triacrylate (PETA) content

Stable emulsions (solid content: 38%) of emulsifier-/N-methylpyrrolidone (NMP)-free crosslinkable waterborne polyurethane-acrylic hybrids with a fixed acrylic monomer content (20 wt.%) and different molar ratios (mole%) of dimethylol propionic acid (DMPA)/crosslinkable pentaerythritol triacrylate (PETA)(17/23, 22/17, 27/11, 32/5) were successfully prepared. This study examined the effect of mole% of DMPA/PETA on the stability and viscosity of hybrid emulsions, the tensile properties/dynamic mechanical thermal properties of hybrid film samples and the adhesive strengths of formulated adhesives for footwear at both dry and wet states. The tensile strength/modulus, storage modulus and Tgs increased with increasing PETA content. The adhesive strength at dry state increased with increasing DMPA content up to 27 mole%, and then decreased a little. However, the adhesive strength at wet state decreased with increasing DMPA content. The optimum DMPA/PETA contents were found to be 27/11 mole% to achieve high performance adhesive properties.

Preparation of WPU Wet-Rubbing Fastness Improver

A wet-rubbing fastness improver was prepared by two steps: (1) synthesis of waterborne polyurethane (WPU) through the reaction of diphenylmethane diisocyanate (MDI), polyethylene glycol (PEG), dimethylol propionic acid (DMPA), and diethylenetriamine; (2) modification of WPU by reaction with epichlorohydrin. Influence of temperature, time, concentration and ratio of monomers on the preparation was studied. The optimal process for WPU synthesis is as follows: temperature 100°C, time 3h, diethylenetriamine 1.5 % and DMPA7% (on weight of monomers). The modification reaction can be proceeded at temperature 100°C for 2h with epichlorohydrin 2.7 %.

Preparation of 2,2-Dimethylol Propionic Acid

2,2-Dimethylol propionic acid was synthesized by two steps using sodium hydroxide as the catalyst in this article. The influence of various factors on the yield of 2,2-Dimethylol propionic acid were studied by single factor experiment that included condensation temperature, condensation time, propionaldehyde-formaldehyde ratioetc.. On the basis of this foundation, the orthogonal design was carried out in order to confirm the preferable synthesis conditions of 2,2-Dimethylolpropanoic. The results show that the optimal synthesis conditions are as follows: condensation time is 8 hours, condensation temperature is 35°C, propionaldehyde-formaldehyde ratio is 2.2, sodium hydroxide-formaldehyde ratio is 0.03, the oxidation temperature is 90°C, oxidation time is 6 hours. The product yield can reach to 71.35% under these reaction conditions that is higher than the value reported in references.

Synthesis and Property of Water Borne Polyurethane/Modified Nano-ZnO Composites Packaging Membranes

Water borne polyurethane /modified nano-ZnO composites packaging membranes were synthesized from modified nano-ZnO, polybutyleneadipate glycol (PBA), polycaprolactone (PCL) isophorne diisocyanate (IPDI), dimethylol propionic acid (DMPA), ethylenediamine(EDA) by self-emulsified method. The phase property, mechanical, antibacterial and anti-ultraviolet properties of the composites packaging membranes influenced by the modified nano-ZnO content were studied by scanning electron microscopy (SEM), mechanical testing, and antibacterial testing. And the relative results were analysed.

Research of Arylic-Terminated Hyperbranched Polyester Modified Styrene-Acrylic Emulsion

Hhyperbranched polyester (HBPE) was synthesized with trimethylol propane and 2,2-dimethylol propionic acid, and arylic-terminated hyperbranched polyester (AHBP) was got by modified its terminal groups with maleic anhydride.AHBP used as copolymerization monomer on modification of styrene-acrylic emulsion. Results show that AHBP could be used for emulsion polymerization,with the increase of dosage,gel fraction in the process of polymerization gradually increased,emulsion stability of calcium ions increased nearly three times, viscosity of emulsion most decreased by 29%,and hardness of emulsion film increased by 1 grade from 2B to B.

Synthesis and properties of polysiloxane graft waterborne polyurethane modified with α-N,N-dihydroxyethylaminopropyl-ω-butylpolydimethylsiloxane

In this study, α-N,N-dihydroxyethylaminopropyl-ω-butylpolydimethylsiloxane was used to prepare waterborne polyurethane-polysiloxane graft copolymer dispersions. α-N,N-dihydroxyethylaminopropyl-ω-butylpolydimethylsiloxane was synthesized via hydroxyl protection, alkylation, anionic ring-opening polymerization, hydrosilylation, and deprotection. Waterborne polyurethane-polysiloxane graft copolymers were prepared by the reaction of poly propylene glycol (PPG), toluene diisocyanate (TDI), 2,2-dimethylol propionic acid (DMPA), 1,4-butanediol (BDO), and α-N,N-dihydroxyethylaminopropyl-ω-butylpolydimethylsiloxane. The water absorption of copolymer films decreased from 163.9 to 17.3% when polysiloxane content increased from 0 to 5%. The tensile strength of the copolymer films increased from 14.0 MPa to 26.3 MPa and decreased when polysiloxane content was more than 3%. The results revealed that the properties of waterborne polyurethane-polysiloxane graft copolymer dispersions and films were improved by grafting polysiloxane chains to polyurethanes.