2026-04-17T07:26:06Zhttps://recercat.cat/oai/request

oai:recercat.cat:10256/206702024-06-18T12:06:55Zcom_2072_452955com_2072_2054col_2072_453062

00925njm 22002777a 4500 dc Oliver Ortega, Helena author Reixach Corominas, Rafel author Espinach Orús, Xavier author Méndez González, José Alberto author 2022-02-02 In the present work, a functionalization of polylactic acid (PLA) has been carried out to anchor maleic anhydride onto the main polymer chain to promote improvement in the compatibility of this polymer matrix with cellulose fibres. Low-molecular-weight PLA has been reacted with maleic anhydride following different procedures: a bulk reaction in an internal mixer and a solution reaction. The presence of oxygen during bulk processing did not allow for functionalization, guiding the reaction towards a decrease in the molecular weight of the material. On the contrary, a controlled reaction under an inert atmosphere in the presence of dioxane as the solvent, at reflux temperature, led to the functionalization of the polymer reaching different yields depending on the percentage of radical initiator and maleic anhydride added and reaction time. The yield of functionalization has been monitored by acid number titration as well as 1H NMR, with optimal yield values of functionalization being up to 3.5%. The PLA-functionalized formula has been used to make commercial PLA compatible with cellulose fibres derived from a thermomechanical treatment. The addition of 10% w/w of fibres to PLA increases the ultimate tensile strength (UTS) of PLA by up to 15%. The incorporation of 4 w/w of the already-functionalized coupling agent to the composite produces improvements in UTS of up to 24% regarding PLA, which confirms the functionalization from a performance point of view This research was funded by Spanish government MINECO in the framework of project MAT2017-83347-R http://hdl.handle.net/10256/20670 Àcid polilàctic Polylactic acid Plàstics biodegradables Biodegradable plastics Maleic Anhydride Polylactic Acid Coupling Agent Prepared from Solvent Reaction: Synthesis, Characterization and Composite Performance