Evaluating the fire resistance and durability of cotton textiles treated with a phosphoramide phosphorus ester phosphate ammonium flame retardant.

The phosphoramide phosphorus ester phosphate ammonium (PPEPA) flame retardant was synthesized by phosphorus oxychloride and ethanolamine, and its structure was characterized by nuclear magnetic resonance and Fourier transform infrared spectroscopy (FTIR). Cotton textiles treated with 20 wt% PPEPA (CT-PPEPA3) would have high durability and flame retardance. The limiting oxygen index (LOI) of CT-PPEPA3 was found to be 46.5 %, while after undergoing 50 laundering cycles (LCs) following the AATCC 61-2013 3 A standard, the LOI only decreased to 31.4 %. Scanning electron microscopy and X-ray diffraction analyses suggested the penetration of PPEPA molecules into the interior of cotton fibers, resulting in a minor alteration of the cellulose crystal structure. The excellent durability, FTIR, and energy-dispersive X-ray of CT-PPEPA3 provided evidence for the formation of -N-P(=O)-O-C- and -O-P(=O)-O-C- covalent bonds between the PPEPA molecules and cellulose. The -N-P(=O)-O-C- bond exhibited a p-π conjugation effect, leading to enhanced stability and improved durability of the flame-retardant cotton textiles. Vertical flame, thermogravimetric, and cone calorimetry tests demonstrated that the CT-PPEPA3 underwent condensed-phase and synergistic flame retardation. Additionally, these finished cotton textiles retained adequate breaking strength and softness, making them suitable for various applications. In conclusion, the incorporation of the -N-P(=O)-ONH4 group into the phosphorus ester phosphate ammonium flame retardant demonstrated effective enhancement of the fire resistance and durability of treated cotton textiles.

A cationic, durable, P/N-containing starch-based flame retardant for cotton fabrics.

A cationic, durable flame retardant for cotton fabrics, 6-(2-(dimethoxy phosphoryl)-2-(trimethyl ammonium)) methoxy-2-methoxy-polysaccharide ammonium phosphate (DTPAP), was synthesized. Its structure was verified by NMR and FTIR spectroscopy. According to the FTIR spectra and X-ray photoelectron spectroscopy (XPS), DTPAP formed P(=O)-O-C bonds with cellulose molecules and firmly grafted to cotton fabrics, giving the fabric a high durability. DTPAP-25-treated fabrics passed the vertical flame test (VFT), and the limiting oxygen index (LOI) was 43.9 %. After 50 laundering cycles (LCs), the DTPAP-25-treated fabrics had an LOI of 29.9 %, passed the VFT, and retained their flame retardancy. EDS data showed that, compared with engrafted cationic ammonium phosphate flame retardants, the DTPAP-treated fabrics contained fewer metal ions. Cone calorimetry data showed that DTPAP-25-treated fabrics did not display concentrated heat release. The results suggested that DTPAP exhibited a condensed-phase flame retardant mechanism, and the introduction of cations into the ammonium phosphate flame retardant reduced ion exchange, which improved the durability.

Synthesis and evaluation of an eco-friendly and durable flame-retardant cotton fabrics based on a high-phosphorous-content.

Cotton fabrics are extremely flammable. Therefore, ammonium salt of dipentaerythritol hexaphosphoric acid (ADPHPA), a novel reactive phosphorus flame retardant without halogen and formaldehyde, was synthesized by solvent-free synthesis method. Surface chemical graft modification was chosen to introduce flame retardant, imparting its flame retardancy and washability. SEM indicated that ADPHPA entered the interior of cotton fiber, which was grafted with OH of control cotton fabrics (CCF) by forming POC covalent bonds to obtain treated cotton fabrics (TCF). There were no apparent differences in the fiber morphology and crystal structure after treatment according to SEM and XRD analysis. TG analysis demonstrated that the decomposition process of TCF was changed compared with CCF, while lower heat release rate and total heat release of TCF indicated its combustion efficiency was also reduced based on cone calorimetry test. Meanwhile, in the durability test, TCF had undergone 50 laundering cycles (LCs) in accordance with AATCC-61-2013 3A standard and had a short vertical combustion charcoal length, which were able to be regard as durable flame-retardant fabrics. The mechanical properties of TCF decreased to a degree, but did not affect the actual use of cotton fabrics. Taken as a whole, ADPHPA has research significance and development potential as a durable phosphorus-based flame retardant.

Postoperative delirium after long-term general anesthesia in elderly patients, how to reduce it?: Protocol of a double-blinded, randomized, placebo-controlled trial.

BACKGROUND: Long operation duration (>4 hours' anesthesia) of laparotomy in elderly patients would increase the risk of postoperative delirium (POD), which is characterized by acute cognitive dysfunction, changes in the level of consciousness, obvious attention disorder, emotional disorder, and sleep-waking cycle disorder. The occurrence of POD is closely related to the risk of death, and it will also seriously affect the cognitive function of patients, prolong postoperative hospital stays, and increase medical expenses. It is known that dexmetomidine could function in sedation, analgesia and anti-sympathetic effect, and it also could simulate the normal sleep state of human body, but there is still a lack of clinical study of dexmedetomidine on the incidence of POD in elderly patients undergoing long-term general anesthesia in laparotomy. METHODS: This is a single-center, double-blinded, randomized controlled study. With the approval of the Ethics Committee of Chongqing Shapingba District People's Hospital, participants who meet the requirements will be randomly divided into the treatment group (continuous infusion of dexmetomidine) and the control group (continuous infusion of 0.9% sodium chloride solution) in a ratio of 1:1. The incidence of delirium, cognitive function score, inflammatory factors, and adverse reactions will be evaluated after the operation. Finally, the data will be analyzed by SPSS 22.0. CONCLUSION: The results of this study will explore the efficacy and safety of dexmetomidine in reducing the incidence of postoperative delirium in elderly patients undergoing long-term general anesthesia in laparotomy. TRIAL REGISTRATION: OSF Registration number: DOI 10.17605/OSF.IO/2GJY6.