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A series of two-component UV-curable waterborne CO2-based polyurethane dispersions (UV-PUDs) with excellent flexibility and mechanical strength were synthesized from poly(propylene carbonate) diol (PPCD), isophorone diisocyanate (IPDI), 2,2-bis(hydroxymethyl) propionic acid (DMPA), 2-hydroxyethyl acrylate (HEA), pentaerythritol triacrylate (PETA) and 1,4-butanediol (BDO). One component was UV-curable waterborne polyurethane terminated by HEA and PETA (molar ratio 1:1), and the other component was linear waterborne polyurethane. The content of the UV-curable component in UV-PUD was 15%, 30%, 45%, 60%, and 100% (weight content). The obtained cured films exhibited superior flexibility without loss of tensile strength, accompanied by excellent acid and alkali resistance. In particular, the dried UV-PUD films without curing showed good mechanical properties. [ABSTRACT FROM AUTHOR]

The subject of this study was the application of a novel CO2-based low-molecular weight poly (propylene carbonate) diol (PPCD) in the field of adhesive. Two-component polyurethane adhesive (PPCD-PU) was prepared with PPCD and polymethylene polyphenyl polyisocyanate (PAPI) as raw materials, propylene carbonate diol (PCD-EDA) as extender. The effects of the molecular weight, carbonate linkage content of PPCD and content of PCD-EDA on the properties of PPCD-PU were also investigated. The results showed that the novel CO2-based low-molecular weight poly (propylene carbonate) diol had higher carbonate linkage content (35%). The PPCD-PU synthesized by the PPCD had good adhesion performance, and the lap shear strength reached to 15 MPa. The addition of PCD-EDA not only improved the bonding properties of the adhesive, but also made PPCD-PU adhesive achieved higher lap shear strength in a shorter curing time. When the amount of PCD-EDA was 20 wt.%, the lap shear strength increased to 17 MPa, and the lap shear strength increased significantly from 3.7 to 10.6 MPa after curing at 80 °C for 30 min. Water absorption rate of PPCD-PU film was about 1.7%, and the lap shear strength was almost unchanged after 24 h of immersion in water. The temperature of 5%-weight loss of PPCD-PU was 284 °C, and the glass transition temperature was 79.3 °C. All the polyurethane adhesives obtained performed good heat and water resistance. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries with high sulfur utilization, long‐cycle life, and dendrite‐free features hold great promise for the development of next‐generation energy storage devices of high energy density. Considerable efforts have been committed to solving the polysulfide shuttle problem toward highly stable Li–S batteries. Here, a unique polymer network containing dually anchored ionic liquids (DA‐PIL) is devolped to improve the cycling performance and coulombic efficiency of Li–S batteries. This DA‐PIL electrolyte incorporates the amphiphilicity of both the polysulfides anion and lithium cation, creating an ionic function layer on polypropylene separator. Noteworthily, the DA‐PIL network is "clean" in the sense that no free ionic specifies are introduced to the electrolyte system. The DA‐PIL layer not only enables strong supression against polysulfide shuttling but simultaneously allows fast lithium transportation owing to cooperate electrostatic interaction among anchored cations and anions. The DA‐PIL layer functionalized on a polypropylene separator can boost excellent stability of Li–S battery with >1600 h cycling test at 0.25 mA cm−2. The Li–S cell with DA‐PIL layer delivers a higher discharge capacity of 827.4 mAh g−1 at 1C. A discharge capacity of 630.6 mAh g−1 is retained after 1000 cycles. [ABSTRACT FROM AUTHOR]

Propylene carbonate diols (PCD) were synthesized from propylene carbonate and ethylenediamine (EDA), iso-phorone diamine (IPDA) and diethylenetriamine (DETA), respectively. The obtained PCDs were used as extenders to prepare the waterborne polyurethane (WPU). The properties of PCD based WPUs were compared to the that of WPU used butane-1,4-diol (BDO) as extender. The structures of PCDs were characterized by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR). The yields, melting points and viscosity of PCDs were tested. The mechanical properties, water absorption, water contact angle, adhesion, pencil hardness, thermal gravimetric analysis (TGA), differential scanning calorimeter (DSC) and dynamic mechanical analysis (DMA) of WPU films were also characterized. The results showed that PCDs with urethane bond in the structure were successfully synthesized and the yields were approximately 99% after 3 h of reaction. Compared to the WPU used BDO as extender, WPU films derived from PCDs exhibited superior tensile strength, outstanding adhesion and pencil hardness, lower water contact angle and water absorption, and higher initial thermal decomposition temperature. [ABSTRACT FROM AUTHOR]