Methanolysis of Poly(lactic Acid) Using Catalyst Mixtures and the Kinetics of Methyl Lactate Production.

Polylactic acid (PLA) is a leading bioplastic of which the market share is predicted to increase in the future; its growing production capacity means its end-of-life treatment is becoming increasingly important. One beneficial disposal route for PLA is its chemical recycling via alcoholysis. The alcoholysis of PLA leads to the generation of value-added products alkyl lactates; this route also has potential for a circular economy. In this work, PLA was chemically recycled via methanolysis to generate methyl lactate (MeLa). Four commercially available catalysts were investigated: zinc acetate dihydrate (Zn(OAc)2), magnesium acetate tetrahydrate (Mg(OAc)2), 4-(dimethylamino)pyridine (DMAP), and triazabicyclodecene (TBD). Dual catalyst experiments displayed an increase in reactivity when Zn(OAc)2 was paired with TBD or DMAP, or when Mg(OAc)2 was paired with TBD. Zn(OAc)2 coupled with TBD displayed the greatest reactivity. Out of the single catalyst reactions, Zn(OAc)2 exhibited the highest activity: a higher mol% was found to increase reaction rate but plateaued at 4 mol%, and a higher equivalent of methanol was found to increase the reaction rate, but plateaued at 17 equivalents. PLA methanolysis was modelled as a two-step reversible reaction; the activation energies were estimated at: Ea1 = 25.23 kJ∙mol-1, Ea2 = 34.16 kJ∙mol-1 and Ea-2 = 47.93 kJ∙mol-1.

[Professional policies: a qualitative study of perceptions and opinions of professionals nurses/midwives and students attending the Master of Science in Nursing]. / Politiche professionali: studio qualitativo sulle percezioni e le opinioni dei professionisti infermieri/ostetriche e degli studenti della Laurea magistrale in Scienze infermieristiche e ostetriche.

INTRODUCTION: Politics, the science and the art of administering public affairs, is a very important field. Dealing with professional policy means to dedicate ourselves to the good of the profession. Professional policies are an integral part of taking care; the professional family needs clear reference points: training, tutoring, promotion and institutional representation. AIM: Exploring perceptions, ideals, shared imagination and desires about the professional policies of nurses/midwives and of master's students in order to be able to have a representation of the reality and to start a critical reflection on the subject. METHOD: A qualitative study was conducted on a proactive sample of 22 nurses / midwives as qualified witnesses of the national situation. The data was collected through a questionnaire built ad hoc. RESULTS: From the analysis of the answers given to the questionnaire, we identified 10 main themes. In the training sector two of the themes that were selected are the importance of the new knowledges and inadequate differentiation of the positions; Regarding the working sector two of the themes that came out are the lack of meritocracy and of new opportunities; meanwhile, in the research field one of the main theme identified is the gap between the theory and the practice. CONCLUSION: The present study finds out that participation in policy-making processes is occasional and of little intensity: just few nurses/midwives are actively involved in the promotion and development of projects in the health sector and of healthcare policies.