This study deals with the synthesis of some nonionic waterborne polyurethanes (PUs), using ethyldiamines of different chain length, such as ethylenediamine (EDA) and diethyltriamine (DETA), as the chain extender in the reaction, and examines the thermal properties, mechanical properties, and dyeing properties of the PU products and their blends. As far as each PU by itself is concerned, we found that the T g of the one made with DETA is the highest, followed by that with EDA, and the one with 1,4-butanediol (1,4-BD) is the lowest. The PU made with 1,4-BD as the chain extender has no T m , while the two others, using diamines as chain extenders, have a clear T m , the one with DETA being higher than that with EDA. However, the enthalpy data are just the opposite. The tensile strengths of the two PUs, made with diamines as the chain extender, are larger than that made with 1,4-BD, but their respective elongation properties are just the opposite. A comparison within PUs made with diamines showed that the one made with EDA is greater in both strength and elongation categories than that made with DETA. However, the one made with DETA is far superior to both of those made with 1,4-BD and EDA in their dyeexhaustion ratio, color yield (K/S), fixation rate, and color fastness. In respect to the various PU mixtures that we examined, we found that both PUs synthesized with EDA or DETA as the chain extender would have their T g 's greatly increased by blending in some PU made using 1,4-BD as the chain extender. Among them, in particular, a blend of PU, made separately with DETA and 1, 4-BD as the chain extender, showed great improvements in both tensile strength and elongation and also demonstrated better dyeability.

ABSTRACT:The cationic-nonionic dispersing centers with different chain lengths of poly ethylene glycol methyl ether (N-PDEA 750, N-PDEA 2000) were prepared from N-diethanol amine (NDEA), isophorone diisocyanate (IPDI), and poly(ethylene glycol methyl ether) (PEO M w ϭ 750 and 2000), whereas aqueous cationic-nonionic polyurethane (N-PDEA PU) with different side chain lengths were prepared by N-PDEA 750 (or N-PDEA 2000), 4,4-methylene bis(isocyantocyclohexane) (H 12 MDI), polytetramethylene glycol (PTMG 2000), ethylene diamine (EDA), and glycolic acid (GA) as cationic-nonionic dispersing center, hard segment, soft segment, chain extender, and quarternizing agent, respectively. The thermal and mechanical properties of PU casting film were then discussed. We also used N-methyldiethyolamine (N-MDEA) without PEO as cationic dispersing center to synthesize aqueous cationic PU (N-MDEA PU). The PU blends were blending N-PDEA 750 PU and N-MDEA PU by different weight ratios and the physical properties of casting films and coated fabric of PU and PU blends were investigated. Regarding the thermal properties, we have found out that the cationic-nonionic PU (N-PDEA 750 PU, N-PDEA 2000 PU) has lower T gs , T ms , T mH , and ⌬H H than N-MDEA PU, apart from ⌬H s . The N-PDEA 2000 PU with longer side-chain PEO has lower T gs , higher T ms and ⌬Hs than N-PDEA 750 PU. As for mechanical property, N-PDEA PU has lower tensile strength of casting film compared with N-MDEA PU. Regarding the comparison of side chain length of PEO, N-PDEA 2000 PU with longer side chain has higher tensile strength than N-PDEA 750 PU with shorter side chain length. In addition, N-PDEA 2000 PU group that shows hard property in stress-strain curve, whereas N-PDEA 750 PU shows soft property. The tensile strength of PU blends decreases as the content of N-PDEA 750 PU increases. When the low-blend ratio of N-PDEA 750 PU (e.g., 5%), the tensile strength of casting film only shows less influence that can improve the elongation effectively. In terms of coating-treated fabrics, cationic-nonionic PU-coated fabrics show lower waterproof capacity (WP) than those treated by cationic PU. However, the water vapor permeability (WVP) and antiyellowing of the N-PDEA 750 PU coated fabrics are significantly better than the one treated by cationic polyurethane.

The aims of this series of studies were to improve the characteristics of polylactic acid (PLA) composites, including toughness modification and photo-degradability suppression. For toughness modification, polybutylene succinate (PBS) was used to modify the toughness of PLA material, and for photo-degradability suppression, ultraviolet (UV) absorbers and hindered amine light stabilizers (HALS) were used to restrain the photo-degradability of PLA material. The composite granules were produced by twin-screw extrusion followed by film extrusion, and the Taguchi method and principal component analysis are used to optimize processing parameters for toughening modification analysis. Through differential scanning calorimetry testing and melt flow index analysis it was determined that this combination of PLA-based composite material had good compatibility, processing flowability and weather resistance. Compared with pure PLA, it was found that the bending strength was decreased by 27.49%, the tensile strength was increased by 13.47% and impact strength was increased by 22.95%, when the processing parameter of the PBS blending ratio was 10 wt% and the mixing of UV absorbers and HALS blending ratio was 0.5 wt%. The screw speed of the twin-screw mixer extruder was 200 rpm, and the die head temperature was 220℃. After 480 hours of UV accelerated aging testing, the retention rate of tensile strength was 94.86%, which is higher than that of pure PLA by 44%. The retention rate of breaking elongation was 85.17%, which was higher than that of pure PLA by 35.17%.

In this study, a series of nonionic waterborne polyurethanes containing side chain poly(ethylene glycol) monomethyl ether (PEGME) were synthesized using 4,4-methylene bis(isocyanatocyclohexane), the nonionic dispersing center produced by isophorone diisocyanate, N-diethanol amine, and PEGME, and a series of soft segments [polyethylene glycol (PEG), polypropylene glycol (PPG), polytetramethylene glycol (PTMG), and polycaprolactone (PCL)] with a different molecular weight. The solution properties of the polyurethane (PU) dispersions, thermal properties of the PU casting films, and the water vapor permeability (WVP) of the PU coated fabrics were investigated. Our results show that the surface tension of PU dispersion and its contact angle to untreated nylon fabric are higher for the ether-based PU dispersion than for the esterbased PU dispersion, with a sequence of PEG-PU > PTMG-PU > PPG-PU > PCL-PU. Both the surface tension and the contact angle between PU dispersion and nylon fabric increase upon increasing the M w of the soft segment. As for the thermal property of PU film, the T g s of PCL-PU is the highest, followed by PEG-PU, PTMG-PU, and PPG-PU, and the T g s decreases with the increase in the length of the soft segment. The T m s follows the order: PEG-PU > PCL-PU > PPG-PU > PTMG-PU, and the T m s increases upon increasing the soft segment length. As regard to PU coated fabric, the trend of WVP is PEG-PU > PTMG-PU > PPG-PU > PCL-PU, which increases with the increasing the soft segment length. With regarding to application for the coating, the Coated-PU with PEG-PU has an excellent WVP.

Cationic aqueous polyurethane (CAPU) coatings were prepared by the acetone process using 4,4-methylene bis (isocyantocyclohexane) (H12MDI), N-methyldiethyolamine (N-MDEA) and a series of various polydiols (polyethylene glycol (PEG), polypropylene glycol (PPG) and polytetramethylene glycol (PTMG) for ether-type polyols and polycaprolactone (PCL) for ester-type polyol) with different molecular weights (Mn =1000, 2000 and 3000 g/mole). The surface tension of CAPU dispersion, contact angle, thermal properties of CAPU casting film and its tensile strength were examined. The waterproof (WP) and water vapor permeability (WVP) of coated fabric and its washing durability were also studied. Our results showed the ether-based CAPU showed a higher surface tension value, contact angle and WVP with a sequence of PEG-PU > PTMG-PU > PPG-PU > PCL-PU, and it increased with increasing M n of the soft segment. As for the thermal properties, the PEG-PU had the highest glass transition temperatures of the soft segment (Tgs) and melting point (Tms) than those of PCL -PU, PTMG-PU and PPG-PU. For the thermal stability of CAPUs casting film, the PEG-PU had ideal thermal stability, followed by PTMG-PU and PCL -PU, and the CAPU with a larger M n of the soft segment had better thermal stability. The PTMG-PU had excellent tensile strength, followed by PCL -PU and PPG-PU. For coated fabric, the trend of WVP followed the order: PEG-PU > PTMG-PU > PPG-PU > PCL -PU, while the WP followed the order: PTMG-PU > PCLPU > PPG-PU > PEG-PU. Finally, the CAPUcoated fabric had an excellent performance after washing and its wash-durability was still 80 %.