Fire‐Safe Polyesters Enabled by End‐Group Capturing Chemistry

Abstract

Upon heating,p olyesters decompose to small molecules and release flammable volatiles and toxic gases, primarily through chain scission of their ester linkages,a nd therefore exhibit poor fire-safety properties,t hus restricting their applications.R eported herein is an end-group-capturing effect of (bis)oxazoline groups,g enerated from the thermal rearrangement of the N-(2-hydroxyphenyl)phthalimide (HPI) moiety whichw as incorporated into the polyester chain by copolymerization. These copolyesters,asaresult, exhibit high efficiency in retarding decomposition by capturing the decomposed products,p articularly for the carbonyl-terminated fragments,t hus increasing the fire-safety properties,s uch as selfextinguishing,a nti-dripping,a nd inhibiting heat release and smoke production. The successful application of this method in both semi-aromatic and aliphatic polyesters providepromising perspectives to designing versatile fire-safe polymers. Figure 2. Pyrolysis and decomposition process of PET and PET-co-HPI 20 .T hree-dimensional TG-IR spectra of PET (a) and PET-co-HPI 20 (b). c) Absorbanceintensity change of CO 2 and carbonyl group as afunction of time obtained from TG-IR. d) Characteristic chromatographic peak of bisbenzoxazole derivate detected from Py-GC/MS. e) Thermalr earrangement process of PET-co-HPI.

Flame-retarding battery cathode materials based on reversible multi-electron redox chemistry of phenothiazine-based polymer

“…In particular, p-BrPhPT with 2.64 wt% Br exhibited the lowest pHRR. Incorporating more flame-retarding units did not further lower the pHRR or THR because of the limited effect on inhibiting the heat release [49][50][51] . Compared with p-PhPT, p-BrPhPT with 2.64 wt% Br showed a significant 32.7% pHRR decrease.…”

Influences of 4ZnO·B2O3·H2O whisker based intumescent flame retardant on the mechanical, flame retardant and smoke suppression properties of polypropylene composites

“…In general, neat PP is very easy to ignite and always generates serious melt drips. Thus, in order to accurately evaluate the self‐extinguishing and anti‐dripping performance of PP composites, UL‐94 vertical burning tests were used 70 . The results and photographs are shown in Figure 3.…”

Flame retardance enhancement of polyacrylonitrile with dimethyl vinylphosphonate

“…Polyacrylonitrile (PAN), a well‐known commercial product, is usually served as the manufacturing of membranes 1,2 and textile fibers due to its excellent softness, warmth retention, abrasive resistance, weather resistance, chemical and solvent resistance, as well as mildew resistance properties 3 . However, since the PAN polymer is highly flammable, with a limiting oxygen index (LOI) number of only 17%–20%, it greatly restricts its application in certain regimes with high fire‐safety requirements, such as carpet, decorate used in vehicle, aircraft, or train 4–7 …”

“…3 However, since the PAN polymer is highly flammable, with a limiting oxygen index (LOI) number of only 17%-20%, it greatly restricts its application in certain regimes with high fire-safety requirements, such as carpet, decorate used in vehicle, aircraft, or train. [4][5][6][7] Till now, several approaches have been proposed to improve the flame retardance of PAN by introducing flameretardant compounds. Horrocks et al [8][9][10] studied the performance of various inorganic and organic phosphorus flame retardants in PAN, and discussed the possible flameretardant mechanism.…”