title: Effect of carboxylic acids as compatibilizer agent on mechanical properties of thermoplastic starch and polypropylene blends.
abstract: In this work, polypropylene/thermoplastic starch (PP/TPS) blends were prepared as an alternative material to use in disposable packaging, reducing the negative polymeric environmental impact. Unfortunately, this material displays morphological characteristics typical of immiscible polymer blends and a compatibilizer agent is needed. Three different carboxyl acids: myristic (C14), palmitic (C16) and stearic acids (C18) were used as natural compatibilizer agent (NCA). The effects of NCA on the mechanical, physical, thermal and morphological properties of PP/TPS blends were investigated and compared against PP/TPS with and without PP-grafted maleic anhydride (PPgMA). When compared to PP/TPS, blends with C18, PPgMA and C14 presented an improvement of 25, 22 and 17% in tensile strength at break and of 180, 194 and 259% in elongation at break, respectively. The highest increase, 54%, in the impact strength was achieved with C14 incorporation. Improvements could be seen, through scanning electron microscopy (SEM) images, in the compatibility between the immiscible components by acids incorporation. These results showed that carboxylic acids, specifically C14, could be used as compatibilizer agent and could substitute PPgMA.
authors.affiliation: Polymeric Materials Lab, Materials Engineering Department, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, P.O. Box 15090, ZC 91501-970 Porto Alegre, RS, Brazil. Electronic address: andrea.bercini@ufrgs.br.
authors.forename: Andréa Bercini
authors.initials: AB
authors.lastname: Martins
authors.affiliation: Polymeric Materials Lab, Materials Engineering Department, Federal University of Rio Grande do Sul, Av. Bento Gonçalves, 9500, P.O. Box 15090, ZC 91501-970 Porto Alegre, RS, Brazil. Electronic address: ruth.santana@ufrgs.br.
authors.forename: Ruth Marlene Campomanes
authors.initials: RM
authors.lastname: Santana
mesh_terms: D002152:Calorimetry, Differential Scanning; D002264:Carboxylic Acids / Q000737:chemistry; D005990:Glycerol / Q000737:chemistry; D008299:Maleic Anhydrides / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D019814:Myristic Acid / Q000737:chemistry*; D019308:Palmitic Acid / Q000737:chemistry*; D010969:Plastics / Q000737:chemistry*; D011126:Polypropylenes / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*; D013229:Stearic Acids / Q000737:chemistry*; D013718:Tensile Strength
chemical_list: D002264:Carboxylic Acids; D008299:Maleic Anhydrides; D010969:Plastics; D011126:Polypropylenes; D013229:Stearic Acids; D019814:Myristic Acid; D019308:Palmitic Acid; C031183:stearic acid; D013213:Starch; D005990:Glycerol
keywords: Carboxylic acids; Compatibilizer; Mechanical and physical properties; Polymer blends; Thermoplastic starch