Synthesis of Castor Oil-based Cationic Waterborne Polyurethane Emulsion and Its Application

Castor oil-based cationic waterborne polyurethane(CWPU)was synthesized by pre-polymer process using castor oil(CO),poly(adipic acid-1,4-succinate diol)(PBA),isophorone diisocyanate(IPDI),and N-methyldiethanolamine(MDEA).The influences of the content of CO and MDEA on comprehensive performance and finished fabric properties of cationic waterborne polyurethane was investigated,especially the antibacterial properties of finished fabric.The CWPU latex particle size and its distribution decrease as the content of CO increased from 0wt%to 16.8wt%,and increases afterwards.The CWPU films show much higher thermal stability than cationic waterborne polyurethane without CO.The surface of fabrics was characterized by scanning electron microscope(SEM).The finished fabric surface is much smoother.In addition,the finished fabric with CWPU emulsion has better antibacterial property against E.coli and S.aureus.When MDEA content is 8%,the antibacterial rates of the two kinds of bacteria are 77.3%and 82.2%,respectively.

Application of Cationic Waterborne Polyurethane as Impregnation Material for Microfiber Synthetic Leather Base

A cationic waterborne polyurethane(CWPU) was synthesized and utilized as impregnation material for manufacturing microfiber synthetic leather base,in an attempt to decrease environmental pollution associated with organic solvents and improve simulation degree relative to genuine leather.The alkali resistance of the CWPU and four manufacture methods were investigated.Meanwhile,the dyeing properties of the microfiber synthetic leather base were studied.It was found that the CWPU displayed enough alkali resistance to endure the alkali deweighting process for microfiber synthetic leather base manufacture.In terms of bending length,bending rigidity,compression elasticity ratio and specific compression elasticity ratio of the resulting base,coagulating the impregnated CWPU with sodium hydroxide before steam treatment was the optimal method.The extent of fiber splitting and the handle of the base from this method were both similar to conventional base filled with solvent-based polyurethane(SPU).The dyeing properties of the microfiber synthetic leather base filled with CWPU were also found superior to the one filled with either anionic waterborne polyurethane(AWPU) or SPU.

Cationic CO_(2)-based Waterborne Polyurethane with High Solid Content and Excellent Ageing Resistance

High solid content CO_(2)-based cationic waterborne polyurethanes(CWPUs)were prepared using CO_(2)-polyols as soft segment and Nmethyl diethanolamine(MDEA)as hydrophilic group.The resulting stable aqueous dispersion displayed a high solid content of 52%with a low MDEA loading of 3.52 wt%.This novel structural CWPU can provide excellent adhesive strength,whose T-peel strength could reach 173.48N/5cm,20%higher than that of ester-based cationic waterborne polyurethane(87.55 N/5cm).The CO_(2)-based CWPU film showed only 2 wt%swelling percentage after 240 min immersion in water,and no change was observed during its immersion in 5 wt%sodium hydroxide solution.The tensile strength of CO_(2)-WPUs dropped slowly to 91.2%after 480 min immersion in a 5 wt%sodium hydroxide solution,whereas that of esterbased CWPUs dropped quickly to 32%after 240 min and their mechanical properties were lost after 360 min immersion.Meanwhile,the retention of the tensile strength of the CO_(2)-CWPUs was 81.5%even after 720 min immersion in 10 wt%H_(2)O_(2) solution,while it was only ca.38%for the ester-based CWPUs.These results indicated that the cationic CO_(2)-based CWPU may be promising waterborne adhesive with outstanding ageing resistance due to its synergistic effect from carbonate and ether groups of CO_(2)-polyol structure.