ResumenEn este trabajo, polietileno de baja densidad (PEBD) fue modificado en estado fundido con un poliester poliol altamente ramificado maleinizado (HBPAM), usando varias proporciones de peróxido de dicumilo (0.5, 1.0, 1.5 y 2.0 %). El análisis infrarrojo mostró las señales de grupos OH, C=O, -COOR y -C=C-del HBPAM en el espectro de las muestras funcionalizadas (PEBD-g-HBPAM). El grado de injerto (GI) fue entre 9.14 y 9.82 %. El índice de fluidez de las muestras PEBD-g-HBPAM fue más bajo que el del PEBD, y no exhibió una dependencia con el contenido de peróxido de dicumilo y GI. Excepto para la muestra obtenida con un 2.0 % de peróxido de dicumilo, todas las temperaturas de fusión de las muestras de PEBD-g-HBPAM fueron similares a la del PEBD. La entalpia de fusión de las muestras de PEBD-g-HBPAM disminuyó con la concentración de peróxido de dicumilo y GI. El módulo ténsil de estas muestras fue más alto que el del PEBD, pero la elongación a la ruptura fue más baja.
This experimental study was carried out with the aim of establishing and analyzing the thermal, structural, morphological, and rheological properties of a polyethylene functionalized with a maleinized hyperbranched polyester. This area of study has scarcely been reported. It is important to study the properties of this material, since it can be employed as functionalizing agent in blends of low density polyethylene and hydrophilic polymers. In addition, it also may be used as alternative for replacing the importation of polyethylene functionalized with maleic anhydride in our country. Therefore, in this experimental study, dicumyl peroxide was utilized to catalyze a functionalization reaction between low density polyethylene and maleinized hyperbranched polyester. In the experiment, dicumyl peroxide concentrations were maintained at 0.50 wt%, 1.0 wt%, 1.5 wt%, and 2.0 wt%. The resultant material after of the functionalization was characterized by various analytic methods including infrared analysis, contact angle, thermogravimetric analysis, X ray diffraction, rheological analysis and scanning electronic microscopy. The functionalization degree of the polyethylene functionalized with a maleinized hyperbranched increased with the dicumyl peroxide amount and in all cases it was higher than 8 weight percent.
This work reports the compatibilization of thermoplastic starch (TPS)/polylactic acid (PLA) blends with a glycerol ester (GE), obtained by modifying glycerol with tall oil fatty acids. The proportions of TPS/PLA studied were 50/50 and 70/30, with the GE amounts from 0 (control sample), 5, 10, 15, and 20 wt%. The effect of the compatibilizer on the structural, thermal, rheological, morphological, mechanical and biodegradation properties of the blends was evaluated. Ultraviolet visible (UV–Vis) analysis of the blends showed that GE improved the light transmission resistance of the materials. The presence of GE resulted in decreased glass transition temperature (Tg) and complex viscosity (η*) values for the blends as opposed to the control sample. Furthermore, η* decreased with the increase in GE content and the η* values were lower than 105 Pa.s. Scanning electronic microscopy analysis revealed that GE improved the interfacial adhesion between TPS and PLA. The tensile modulus (149–414 MPa), tensile strength (5.60–11.6 MPa) and the biodegradability of the blends decreased with GE content, but the water resistance showed an opposite behavior. The GE acted as a plasticizer, compatibilizer and antioxidant for TPS/PLA blends.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.