1. Highly Branched Tannin-Tris(2-aminoethyl)amine-Urea Wood Adhesives
Bengang Zhang, et al. Polymers (Basel). 2023 Feb 10;15(4):890. doi: 10.3390/polym15040890.
Condensed tannin copolymerized with hyperbranched tris(2-aminoethyl)amine-urea formed by amine-amido deamination yields a particleboard thermosetting adhesive without any aldehydes satisfying the requirements of relevant standards for the particleboard internal bond strength. The tannin-triamine-urea cures well at 180 °C, a relatively low temperature for today's particleboard hot pressing. As aldehydes were not used, the formaldehyde emission was found to be zero, not even in traces due to the heating of wood. The effect is ascribed to the presence of many reactive sites, such as amide, amino, and phenolic groups belonging to the three reagents used. The tannin appears to function as an additional cross-linking agent, almost a nucleating agent, for the triamine-urea hyperbranched oligomers. Chemical analysis by MALDI ToF and 13C NMR has shown that the predominant cross-linking reaction is that of the substitution of the tannin phenolic hydroxyls by the amino groups of the triamine. The reaction of tannin with the still-free amide groups of urea is rather rare, but it may occur with the rarer tannin flavonoid units in which the heterocyclic ring is opened. Due to the temperature gradient between the surfaces and the board core in the particleboard during hot pressing, the type and the relative balance of covalent and ionic bonds in the resin structure may differ in the surfaces and the board core.
2. Synthesis of chitosan-based resins modified with tris(2-aminoethyl)amine moiety and its application to collection/concentration and determination of trace mercury by inductively coupled plasma atomic emission spectrometry
Lukman Hakim, Akhmad Sabarudin, Koji Oshita, Mitsuko Oshima, Shoji Motomizu Talanta. 2008 Sep 15;76(5):1256-60. doi: 10.1016/j.talanta.2008.05.025. Epub 2008 May 23.
A novel chitosan-based chelating resin modified with tris(2-aminoethyl)amine moiety (CCTS-TAA) was synthesized, and its characteristics in the collection/concentration of mercury was examined. The synthesized resin showed good adsorption toward mercury in a wide pH range, and the adsorbed mercury can be easily eluted by using 2M HNO(3) without any addition of complexing agent. The resin was then packed in a mini-column and the mini-column was installed on a computer-controlled automated-pretreatment (Auto-Pret) system coupled with inductively coupled plasma-atomic emission spectroscopy (ICP-AES) for on-line mercury collection and determination at trace level.
3. Acrylamides and methacrylamides as alternative monomers for dental adhesives
Stéfani Becker Rodrigues, Cesar Liberato Petzhold, Douglas Gamba, Vicente Castelo Branco Leitune, Fabrício Mezzomo Collares Dent Mater. 2018 Nov;34(11):1634-1644. doi: 10.1016/j.dental.2018.08.296. Epub 2018 Sep 7.
Objective: Synthesize and characterize a methacrylamide monomer for adhesive system and evaluate the physicochemical properties of the adhesive resin. Methods: The liquid methacrylamide monomer N,N',N″-(nitrilotris(ethane-2,1-dyil)tris(2-methylacrylamide) (TMA) was prepared by reaction of methacrylic anhydride and tris(2-aminoethyl)amine with 60% yields. The TMA structure was analyzed by 1H NMR, 13C NMR, ATR-FTIR and UHPLC-QTOF-MS. Experimental adhesive resin containing bisphenol-A glycidyl methacrylate (BISGMA), 2-hydroxyethylacrylamide (HEAA), 2-hydroxyethylmethacrylate (HEMA) and TMA were formulated. Polymerization kinetics of neat TMA and experimental adhesive resin (TMA33%/HEAA66%, TMA50%/HEAA50%, TMA66%/HEAA33%, TMA50%/HEMA50%, BisGMA/HEAA/TMA and BisGMA/HEMA) were evaluated using Differential Scanning Calorimetry. Physiochemical properties for BisGMA/HEAA/TMA and BisGMA/HEMA adhesives were evaluated by cytotoxicity, ultimate tensile strength (UTS), softening in solvent (ΔKHN), contact angle (θ), microtensile bond strength (μTBS) and failure analysis. A primer was also formulated with H2O/HEAA/AMPS (2-acrylamido-2-methylpropane sulfonic acid) and the pH value was verified and compared to commercial primer. Results: Adhesive resin with only HEAA and TMA (TMA33%/HEAA66%, TMA50%/HEAA50%, TMA66%/HEAA33%) showed lower conversion and polymerization rate after 40s of light activation. Conversion up to 60% was found for BisGMA/HEAA/TMA and BisGMA/HEMA adhesive resin without significant difference between groups, p>0.05. Cytotoxicity, UTS, μTBS, ΔKHN and θ showed no statistical difference, p>0.05, between BisGMA/HEAA/TMA and BisGMA/HEMA adhesive resin. Significance: In this study, the proposed synthetic route resulted in a tris(methacrylamide). A new primer composed without acrylates or methacrylates was formulated for 3-step etch-and-rinse adhesive system without the presence of HEMA monomer. Physicochemical properties and cell viability of BisGMA/HEAA/TMA adhesive resin represents an alternative adhesive resin without HEMA monomer.
