Novel Bicomponent Functional Fibers with Sheath/Core Configuration Containing Intumescent Flame-Retardants for Textile Applications

Abstract

The objective of this study is to examine the effect of intumescent flame-retardants (IFR’s) on the spinnability of sheath/core bicomponent melt-spun fibers, produced from Polylactic acid (PLA) single polymer composites, as IFR’s have not been tested in bicomponent fibers so far. Highly crystalline PLA-containing IFR’s was used in the core component, while an amorphous PLA was tested in the sheath component of melt-spun bicomponent fibers. Ammonium polyphosphate and lignin powder were used as acid, and carbon source, respectively, together with PES as a plasticizing agent in the core component of bicomponent fibers. Multifilament fibers, with sheath/core configurations, were produced on a pilot-scale melt spinning machine, and the changes in fibers mechanical properties and crystallinity were recorded in response to varying process parameters. The crystallinity of the bicomponent fibers was studied by differential scanning calorimetry and thermal stabilities were analyzed by thermogravimetric analysis. Thermally bonded, non-woven fabric samples, from as prepared bicomponent fibers, were produced and their fire properties, such as limiting oxygen index and cone calorimetry values were measured. However, the ignitability of fabric samples was tested by a single-flame source test. Cone calorimetry showed a 46% decline in the heat release rate of nonwovens, produced from FR PLA bicomponent fibers, compared to pure PLA nonwovens. This indicated the development of an intumescent char by leaving a residual mass of 34% relative to the initial mass of the sample. It was found that the IFRs can be melt spun into bicomponent fibers by sheath/core configuration, and the enhanced functionality in the fibers can be achieved with suitable mechanical properties.

Biobased Dyes as Conductive Additives to Reduce the Diameter of Polylactic Acid Fibers during Melt Electrospinning

“…The T g and T m did not change significantly and remained at~60 • C and~173 • C, respectively, regardless of the additive and weight percent. The temperature values for PLA are consistent with those previously reported in the literature [41,42]. In contrast, the additives had a significant effect on T cc .…”

Self-intumescent polyelectrolyte for flame retardant poly (lactic acid) nonwovens

“…Table 5 lists the fire performance and cost of flame-retardant PLA nonwovens from the published literature and this work. We can see APTris treated PLA nonwovens in this work is inexpensive, more feasible and higher efficiency than the chemical grafted ( Cheng et al, 2016a ), spun-bonded ( Maqsood and Seide, 2019 ) and other flame retardant treated ( Cheng et al, 2016b ) PLA nonwovens. The synthesis of APTris doesn’t involve any toxic solvents, and the involved raw materials have reasonable price and rich source, which is suitable for industrial to produce cleaner flame retardant PLA nonwovens.…”

“… Samples Weight gain (%) LOI (%) THR (kJ/g) pHRR (W/g) Cost a ($) Ref. PLA 0 26.3 18.9 464.9 -- ( Cheng et al, 2016b ) PLA-100PA 18.5 +20.5% -23.8% -29.4% 2.6 PLA-250PA 45.0 +37.3% -38.6% -39.9% 6.3 PLA 0 26.3 18.4 462.0 -- ( Cheng et al, 2016a ) PLA-100/DP-150 3.5 +32.3% -7.6% -4.5% -- PLA-200/DP-150 4.4 +35.0% -8.7% -7.1% -- PLA 0 19.3 -- -- -- ( Maqsood and Seide, 2019 ) PLA/APP5/PES10/KL1 16.0 +30.6% -- -- …”

“…A mixture of phosphonate esters was used to enhance the fire performance of PLA nonwovens ( Avinc et al, 2012 ), after complex drying and curing procedure, the treated fabrics could pass the criteria of NFPA 701 after washing. The sheath/core configuration bicomponent PLA containing intumescent flame retardants were prepared by melt spinning to fabricate PLA nonwovens by thermal bonding ( Maqsood and Seide, 2019 ). The obtained PLA/APP5/PES10/KL3 nonwovens showed a 46.0% reduction in pHRR and a 34.5% increase in residual mass compared pure PLA nonwovens, the LOI value of that increased to 30.4% from 19.3%.…”

Biodegradable Flame Retardants for Biodegradable Polymer

“…IFR composites comprising different formulations were produced with and without carbonization agents by melt extrusion, and their flammability was assessed by UL-94, LOI, and cone calorimetry tests. Cone calorimetry revealed a 50% reduction in the peak heat release rate of the IFR composites in comparison to 100% PLA and confirmed the development of an intumescent char structure containing residue up to 40% [ 93 ].…”