A facile strategy for synthesizing isosorbide-based polyurethane structural adhesives and core-shell rubber.

A structural adhesive series of biomass-based polyurethane (Biomass-PU) is synthesized using polypropylene glycol (PPG2000), isosorbide-based polyol (RPO300) as polyols, isophorone diisocyanate (IPDI) as an isocyanate and 4-tert-butylphenol (BP) as a capping agent. Three different equivalent ratios of PPG2000/RPO300, 9/1 (Biomass-PU1), 7/3 (Biomass-PU2), and 1/1 (Biomass-PU3), are evaluated to determine the effect of isosorbide-based polyol content on the properties and the optimizing formulation of biomass-PU structure adhesive. The 9/1 ratio of PPG2000/RPO300 substantially leads to the improvement of impact strength by up to 35 MPa, and the PPG2000/RPO300 = 9/1 ratio exhibits better thermal properties and impact strength than those of other ratios. To achieve more compatibility between biomass-PU structure adhesive and core-shell rubber (CSR) toughener, novel CSRs are successfully synthesized using acryl-PU as a shell and biomass-based PU as a core. The chemical structure of biomass-PU structure adhesives is analyzed through FT-IR Spectroscopy and NCO% titration. Thermal properties are evaluated using TGA and DSC analysis. Their molecular weights are measured by GPC. Also, the core-shell rubber (CSR) with a polyurethane shell is prepared to reinforce the impact strength of Biomass-PU structure adhesive.

Synthesis of Room Temperature Curable Polymer Binder Mixed with Polymethyl Methacrylate and Urethane Acrylate for High-Strength and Improved Transparency.

Urethane acrylate (UA) was synthesized from various di-polyols, such as poly(tetrahydrofuran) (PTMG, Mn = 1000), poly(ethylene glycol) (PEG, Mn = 1000), and poly(propylene glycol) (PPG, Mn = 1000), for use as a polymer binder for paint. Polymethyl methacrylate (PMMA) and UA were blended to form an acrylic resin with high transmittance and stress-strain curve. When PMMA was blended with UA, a network structure was formed due to physical entanglement between the two polymers, increasing the mechanical properties. UA was synthesized by forming a prepolymer using di-polyol and hexamethylene diisocyanate, which were chain structure monomers, and capping them with 2-hydroxyethyl methacrylate to provide an acryl group. Fourier transform infrared spectroscopy was used to observe the changes in functional groups, and gel permeation chromatography was used to confirm that the three series showed similar molecular weight and PDI values. The yellowing phenomenon that appears mainly in the curing reaction of the polymer binder was solved, and the mechanical properties according to the effects of the polyol used in the main chain were compared. The content of the blended UA was quantified using ultravioletvisible spectroscopy at a wavelength of 370 nm based on 5, 10, 15, and 20 wt%, and the shear strength and tensile strength were evaluated using specimens in a suitable mode. The ratio for producing the polymer binder was optimized. The mechanical properties of the polymer binder with 5-10 wt% UA were improved in all series.