Organosolv lignins as new stabilizers for cellulose nitrate: Thermal behavior and stability assessment.

Cellulose nitrate, commonly known as nitrocellulose (NC), and its corresponding propellants naturally decompose at normal conditions. To avoid early degradation, unexpected explosion, energy loss, and ensure a safe storage, stabilizing agents are often introduced within its compositions. Conventional stabilizers, such as aromatic amines like diphenylamine (DPA) and urea, can produce carcinogenic/toxic substances during propellants shelf life. Thus, a need for alternative stabilizing agents, which offer similar/better effectiveness and display a non/low toxicity, remains a challenge. This paper investigates the stabilizing effect of two organosolv lignins (OL), obtained from Aleppo pine (AP) and Eucalyptus globulus (EG), on NC. For this purpose, conventional stability tests and kinetic modeling are applied for different samples (S1-S4) using 3% of stabilizer, which are S1, pure NC; S2, NC + DPA; S3, NC + OL(AP); and S4, NC + OL(EG). Beforehand, FTIR spectroscopy and DSC analysis have been used to check the compatibility of these potential stabilizers and NC. The obtained results via Bergmann-Jung and vacuum stability tests suggested that the prepared mixtures are stable. The kinetic study based on DSC data using isoconversional methods shows that both stabilizers display a good stabilizing effect. The reactivity between the different organosolv lignins and NOx released during the degradation of NC has been well highlighted using FTIR and TGA analyses. Hence, these efficient, environmentally friendly and readily available substances can be effectively used as stabilizers for NC-based formulations.

Death after withdrawal from dialysis: the most common cause of death in a French dialysis population.

BACKGROUND: Discontinuation of dialysis is a common cause of death in end-stage renal disease (ESRD) patients in North America and the UK, but appears to be unusual in the rest of Europe. The aim of this retrospective study was to characterize withdrawal from dialysis in a French population cohort. METHODS: We assessed the cause of death, and the medical and social characteristics of chronic dialysis patients in a French population who died in 2001. We compared patients who died after withdrawal from dialysis and patients continuing dialysis until death. We determined the decision-making process when dialysis was withdrawn. RESULTS: In a population cohort of 1436 dialysis patients, 196 died (13.9%). Of them, 40 patients (20.4%) died following withdrawal from dialysis. This was the most common cause of death, followed by cardio-vascular disease (18.4%). Patients withdrawing from dialysis had a significantly higher rate of dementia (17.5 vs 6.4%, P = 0.02), a poor general condition (55 vs 15.4%, P < 0.001), and were dependent in their life for everyday activities in comparison with patients who died from other causes. They were not different in age, sex, duration of dialysis treatment, dialysis technique, cardio-vascular disease, diabetes, stroke or cancer, but the sample size was small. Treatment was more often removed in patients with severe medical complications and/or cachexia (90%). The decision to stop dialysis was made most often by a physician (77.5%). CONCLUSION: Death after withdrawing from dialysis was the most common cause of death in ESRD patients in our French population cohort. The patients who died after discontinuation of treatment were more often in a poor general condition, near the end of life, and most often the physician decided to stop dialysis treatment.