A-P100. lnfluence of Ester Diluents and Chain Extension on Polyurethane Viscosities Dalia Bražinskienė,Sandra Mačiulytė, Paulina Nemaniutė, Tadas Matijošius, Svajus J. Asadauskas Center for Physical Sciences and Technology (F TMC), Saulėtekio 3, Vilnius dalia.brazinskiene©ftmc.Il Polyurethanes are often used as adhesives in laminated packaging, where viscosity is critical. Poly diethylene glycol adipate macrodiol was chain—extended with hexamethylene diisocyanate at 1:0.3 mol [1] to produce a polyurethane prepolymer [214 Then it was diluted with ethyl aoetate 1:1 (w/w) to produce the first adhesive component. As the second adhesive component, aromatic tri» isocyanate CAS 53317-61-6 was used at 1.4 moi excess to assure eventual gelation. suo „galui imus um R-eusw m atzdc „ e a m „= = n-ręnuyšžua mm„a atsuc klnematic viewsiw, mm'/s ir m m m heating dviatioh. mm Fig. 1. Viscosity ihcrease during polyurethane addition to trifisocyanate in ethyl acetale Right alter mixing the blend visoosity li was periodically measured per ASTM 0445. The narrow capillary of the Cannon-Fenske viscometer minimized the vaporization of ethyl acetste. Polymerization-inducedthickening was gradual, Fig. 1, with stronger non—linearity observed at 50”C than 25”C. Catalytic effects ofthe ester linkage in ethyl acetate could be responsible for the acceleration of the carbamate formation, since chemical reactivity generally intensilies at higher temperatures. Eventually, the adhesive fonnulation was fortiūed with nanoparticles and suocessiully used to laminate multilayer plastic films and Al foils. Acknnwledgments: This study ms carried out under project TERMINUS, lunded by the European Union under Horizon 2020. ** ' *. Call: HŽGZO-MBF-ST—IND—ZCHS. Grant Agreement: 814400 The * * technical concept and advibes of J. Buechner, T. Fait (Covestro) and ar * A. Strakšys (FTMC) are cordlally appreciated. Keywords: adhesive, meology, gelatl'on, prepalymer. Reference . 1. s. Maclulytė et al. Pmc. BPS p. 40 (2019) 2. s. Mačiulytė et al. Pmc. Chemistry e. Chem. Tech. p, 58 (2019) 128 Al _v— B-P101. Enhancement of the Compati ility between Natural Rubber and Pineappie Leaf Microtibers for Better Stress Transfer in Their Composite Karine Mougin', Budsarapom Surajnrusarn“, Nuttapong Hariwongsanupabz, Gautier Schrodf, Samar Garreau', Taweechai Amornsakchai 'lnstilul de Science des Material/X de Muihouse, lSZM—CNRS » UMR 7361, Universite' de Haute Alsace, F-68100 Mulhouse, France 2Mali/dol University, Department of Chemistry and Center of Excel/once for Innovation in Chemistry, Faculty of Science, Nakhon Pathom, Thailand Karinemougin©uhafr The compatibility between natural rubber (NR) and pineapple leaf microiibers (PALMF) in NR-PALMF composites were improved by two methods. One method was carried out by the addition of nitrile rubber (NBR) during mixing [1]. The other method was by chemically trealing PALMF surface with silane and/or a compatibilizer. Modulus at low strain oi NRePALMF composites increased in both cases. Composite prepared with silane modified PALMF has however higher modulus than that containing NBR indicating better compatibility between NR and PALMF. Modulus at high strain of NR-PALMF composiles has also been increased by addition of carbon black ūlier. This system has been compared to natural rubber reinforcecl by aramid ūbers (see Fig. 1) and has shown better mechanical properties. „.. a .. » Temperature ("C) Flg. 1. Elastic moduli (a“) oiar'arrrid and pineapple leaimicroūbercomposites made of natural rubber (b) SEM micrographs ofcryogenic fractured natural rubber composites at low and high magnilications for b) aramid compcsrte, c) PALMF treated composite Keywords: natural rubber, pinaapple les/libero, composite, rainforcemenr. References: 1. N. Hariwongsanupabet al. Polymer Testing 57 [1.94-100 (2017) 129