Improvement of flame retardancy of poly(lactic acid) nonwoven fabric with a phosphorus- containing flame retardant

Lignin–silica hybrids (LSHs) were prepared by sol–gel method and characterized by Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). LSH and ammonium polyphosphate (APP) were added into poly(lactic acid) (PLA) as a novel intumescent flame-retardant (IFR) system to improve the flame retardancy of PLA. The flame-retardant effect of APP and LSH in PLA was studied using limiting oxygen index (LOI), vertical burning (UL-94) tests and cone calorimeter. The thermal stability of PLA/APP/LSH composites was evaluated by thermogravimetric analysis (TGA). Additionally, the morphology and components of char residues of the IFR-PLA composites were investigated by SEM and XPS. With the addition of APP/LSH to PLA system, the morphology of the char residue has obviously changed. Compared with PLA/APP and PLA/APP/lignin, a continuous and dense intumescent charring layer with more phosphor in PLA composites is formed, which exhibits better flame retardancy. All the results show that the combination of APP and LSH can improve the flame-retardant property and increase the thermal stability of PLA composites greatly.

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Novel Dihydroxy-Containing Ammonium Phosphate Based Poly(Lactic Acid): Synthesis, Characterization and Flame Retardancy

Polymers ◽

10.3390/polym10080871 ◽

2018 ◽

Vol 10 (8) ◽

pp. 871 ◽

Cited By ~ 2

Author(s):

Rong-Kun Jian ◽

Long Xia ◽

Yuan-Fang Ai ◽

De-Yi Wang

Keyword(s):

Lactic Acid ◽

Flame Retardant ◽

Ammonium Phosphate ◽

Acid Synthesis ◽

Poly Lactic Acid ◽

Limiting Oxygen Index ◽

Phosphorus Containing ◽

The Matrix ◽

Degree Of Crystallization ◽

Thermal Stability Of

The aim of this work is to prepare flame-retardant biobased poly(lactic acid) materials through incorporating a novel flame retardant dihydroxy-containing ammonium phosphate (DAP) derived from 2-chloro-5,5-dimethyl-1,3,2-dioxaphosphinane-2-oxide (DOP) and 2-amino-2-methyl-1,3-propanediol (AMPD). Interestingly, PLA modified with only 0.5% DAP passed UL-94 V-0 rating, and possessed a limiting oxygen index (LOI) value of 24.6%, which would further increase with the increasing loading of DAP. PLA/DAP did not exhibit obviously improved results in terms of heat release rate (HRR), as the loading of DAP was relatively low. It was found that DAP showed little effect on the thermal stability of PLA and the onset decomposition temperatures of PLA and PLA/DAP blends were very close. Besides, the degree of crystallization increased because of the plasticized effect of DAP. Based on the analyses of flame-retardant mechanism of DAP, it disclosed that DAP decomposed to generate incombustible compounds, such as water and ammonia, to dilute the concentration of oxygen and fuels, and then release some phosphorus-containing fragments that could produce phosphorus-containing free radicals to interrupt free-radical reactions, and finally noncombustible melt dripping was produced so as to bring away large amount of heat and stop the feedback of heat to the matrix.

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Preparation of microcellular poly(lactic acid) composites foams with improved flame retardancy

Journal of Cellular Plastics ◽

10.1177/0021955x16633644 ◽

2016 ◽

Vol 53 (1) ◽

pp. 45-63 ◽

Cited By ~ 9

Author(s):

Kun Wang ◽

Jingjing Wang ◽

Dan Zhao ◽

Wentao Zhai

Keyword(s):

Lactic Acid ◽

Flame Retardant ◽

Oxygen Index ◽

Poly Lactic Acid ◽

Limited Oxygen Index ◽

Cell Structures ◽

Phosphorus Containing ◽

Flame Retardant Properties ◽

Index Value ◽

Limited Oxygen

In this study, flame-retardant poly(lactic acid) foams with satisfactory cell structures were prepared by microcellular foaming technology using phosphorus-containing flame retardant and graphene as the charring agent. The introduction of 5–30 wt% flame retardant increased the limited oxygen index value of poly(lactic acid) from 19.0 to 26.5–37.8% and simultaneously increased the foam expansion of poly(lactic acid) foams from 4.4 to 5.8–17.5. In addition, all the prepared poly(lactic acid)/flame-retardant composites passed the UL-94 V-0 rating. The addition of 0.5 wt% graphene increased the limited oxygen index value of poly(lactic acid)/flame-retardant composite with flame-retardant content of 15 wt% from 27.9 to 29.2%, and more graphene additions improved the antidripping behavior of poly(lactic acid) composites. The possible mechanisms of the effects of the resultant cellular structure on the flame-retardant properties of poly(lactic acid) composites were also discussed.

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