Improved Thermal Processing of Polylactic Acid/Oxidized Starch Composites and Flame-Retardant Behavior of Intumescent Non-Wovens

Thermoplastic processing and spinning of native starch is very challenging due to (a) the linear and branched polymers (amylose and amylopectin) present in its structure and (b) the presence of inter-and-intramolecular hydrogen bond linkages in its macromolecules that restrict the molecular chain mobility. Therefore, in this study, oxidized starch (OS) (obtained after oxidation of native starch with sodium perborate) was melt-blended with polylactic acid (PLA) polymer to prepare PLA/OS blends that were then mixed together with ammonium polyphosphate (APP), a halogen-free flame retardant (FR) used as acid donor in intumescent formulations on twin-screw extruder to prepare PLA/OS/APP composites. OS with different concentrations also served as bio-based carbonic source in intumescent formulations. PLA/OS/APP composites were melt spun to multifilament fibers on pilot scale melt-spinning machine and their crystallinity and mechanical properties were optimized by varying spinning parameters. The crystallinity of the fibers was studied by differential scanning calorimetry and thermal stabilities were analyzed by thermogravimetric analysis. Scanning electron microscopy was used to investigate the surface morphology and dispersion of the additives in the fibers. Needle-punched non-woven fabrics from as prepared melt-spun PLA/OS/APP fibers were developed and their fire properties such as heat release rate, total heat release, time to ignition, residual mass % etc. by cone calorimetry test were measured. It was found that PLA/OS/APP composites can be melt spun to multifilament fibers and non-woven flame-retardant fabrics produced thereof can be used in industrial FR applications.

Download Full-text

Rapidly Solidified Melt-spun Bi-Sn Ribbons: Surface Composition Issues

JOURNAL OF ADVANCES IN PHYSICS ◽

10.24297/jap.v11i5.369 ◽

2016 ◽

pp. 3287-3297

Author(s):

Tarek El Ashram ◽

Ana P. Carapeto ◽

Ana M. Botelho do Rego

Keyword(s):

Chemical Composition ◽

Optical Microscopy ◽

Melt Spinning ◽

Surface Composition ◽

Electrochemical Process ◽

Melt Spun ◽

Bismuth Alloy ◽

The One ◽

Rapidly Solidified ◽

Melt Spinning Technique

Tin-bismuth alloy ribbons were produced using melt-spinning technique. The two main surfaces (in contact with the rotating wheel and exposed to the air) were characterized with Optical Microscopy and AFM, revealing that the surface exposed to the air is duller (due to a long-range heterogeneity) than the opposite surface. Also the XPS chemical composition revealed many differences between them both on the corrosion extension and on the total relative amounts of tin and bismuth. For instance, for the specific case of an alloy with a composition Bi-4 wt % Sn, the XPS atomic ratios Sn/Bi are 1.1 and 3.7 for the surface in contact with the rotating wheel and for the one exposed to air, respectively, showing, additionally, that a large segregation of tin at the surface exists (nominal ratio should be 0.073). This segregation was interpreted as the result of the electrochemical process yielding the corrosion products.

Download Full-text

Synthesis and characterization of flame-retardant-wrapped carbon nanotubes and its flame retardancy in epoxy nanocomposites

Polymers and Polymer Composites ◽

10.1177/09673911211024582 ◽

2021 ◽

pp. 096739112110245

Author(s):

Jiangbo Wang

Keyword(s):

Carbon Nanotubes ◽

Heat Release ◽

Flame Retardant ◽

Flame Retardancy ◽

Total Heat Release ◽

Pristine Cnts ◽

Peak Heat Release Rate ◽

Ep Matrix ◽

Better Than

A novel phosphorus-silicon containing flame-retardant DOPO-V-PA was used to wrap carbon nanotubes (CNTs). The results of FTIR, XPS, TEM and TGA measurements exhibited that DOPO-V-PA has been successfully grafted onto the surfaces of CNTs, and the CNTs-DOPO-V-PA was obtained. The CNTs-DOPO-V-PA was subsequently incorporated into epoxy resin (EP) for improving the flame retardancy and dispersion. Compared with pure EP, the addition of 2 wt% CNTs-DOPO-V-PA into the EP matrix could achieve better flame retardancy of EP nanocomposites, such as a 30.5% reduction in peak heat release rate (PHRR) and 8.1% reduction in total heat release (THR). Furthermore, DMTA results clearly indicated that the dispersion for CNTs-DOPO-V-PA in EP matrix was better than pristine CNTs.

Download Full-text

Mechanically Sustainable Starch-Based Flame-Retardant Coatings on Polyurethane Foams

Polymers ◽

10.3390/polym13081286 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1286

Author(s):

Kyung-Who Choi ◽

Jun-Woo Kim ◽

Tae-Soon Kwon ◽

Seok-Won Kang ◽

Jung-Il Song ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Coating Layer ◽

Real Life ◽

Polyurethane Foams ◽

Layer By Layer ◽

Toxic Substances ◽

Cone Calorimetry ◽

Coating Agent ◽

Cone Calorimeter Test

The use of halogen-based materials has been regulated since toxic substances are released during combustion. In this study, polyurethane foam was coated with cationic starch (CS) and montmorillonite (MMT) nano-clay using a spray-assisted layer-by-layer (LbL) assembly to develop an eco-friendly, high-performance flame-retardant coating agent. The thickness of the CS/MMT coating layer was confirmed to have increased uniformly as the layers were stacked. Likewise, a cone calorimetry test confirmed that the heat release rate and total heat release of the coated foam decreased by about 1/2, and a flame test showed improved fire retardancy based on the analysis of combustion speed, flame size, and residues of the LbL-coated foam. More importantly, an additional cone calorimeter test was performed after conducting more than 1000 compressions to assess the durability of the flame-retardant coating layer when applied in real life, confirming the durability of the LbL coating by the lasting flame retardancy.

Download Full-text

Synthesis of a bio-based flame retardant via a facile strategy and its synergistic effect with ammonium polyphosphate on the flame retardancy of polylactic acid

Polymer Degradation and Stability ◽

10.1016/j.polymdegradstab.2021.109684 ◽

2021 ◽

pp. 109684

Author(s):

Yuanyuan Zhan ◽

Xujuan Wu ◽

Shasha Wang ◽

Bihe Yuan ◽

Quan Fang ◽

...

Keyword(s):

Synergistic Effect ◽

Flame Retardant ◽

Polylactic Acid ◽

Flame Retardancy ◽

Ammonium Polyphosphate

Download Full-text

Dual UV-Thermal Curing of Biobased Resorcinol Epoxy Resin-Diatomite Composites with Improved Acoustic Performance and Attractive Flame Retardancy Behavior

Sustainable Chemistry ◽

10.3390/suschem2010003 ◽

2021 ◽

Vol 2 (1) ◽

pp. 24-48

Author(s):

Quoc-Bao Nguyen ◽

Henri Vahabi ◽

Agustín Rios de Anda ◽

Davy-Louis Versace ◽

Valérie Langlois ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Epoxy Resin ◽

Flame Retardancy ◽

Sound Absorption ◽

Flexural Modulus ◽

Construction Materials ◽

Acoustic Properties ◽

Low Frequencies ◽

Compacting Pressure

This study has developed novel fully bio-based resorcinol epoxy resin–diatomite composites by a green two-stage process based on the living character of the cationic polymerization. This process comprises the photoinitiation and subsequently the thermal dark curing, enabling the obtaining of thick and non-transparent epoxy-diatomite composites without any solvent and amine-based hardeners. The effects of the diatomite content and the compacting pressure on microstructural, thermal, mechanical, acoustic properties, as well as the flame behavior of such composites have been thoroughly investigated. Towards the development of sound absorbing and flame-retardant construction materials, a compromise among mechanical, acoustic and flame-retardant properties was considered. Consequently, the composite obtained with 50 wt.% diatomite and 3.9 MPa compacting pressure is considered the optimal composite in the present work. Such composite exhibits the enhanced flexural modulus of 2.9 MPa, a satisfying sound absorption performance at low frequencies with Modified Sound Absorption Average (MSAA) of 0.08 (for a sample thickness of only 5 mm), and an outstanding flame retardancy behavior with the peak of heat release rate (pHRR) of 109 W/g and the total heat release of 5 kJ/g in the pyrolysis combustion flow calorimeter (PCFC) analysis.

Download Full-text

Synthesis of Novel Arginine-Based Flame Retardant and Its Application in Lyocell Fabric

Molecules ◽

10.3390/molecules26123588 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3588

Author(s):

Jiayi Chen ◽

Yansong Liu ◽

Jiayue Zhang ◽

Yuanlin Ren ◽

Xiaohui Liu

Keyword(s):

Fourier Transform ◽

Heat Release ◽

Flame Retardant ◽

Photoelectron Spectroscopy ◽

Fourier Transform Infrared ◽

Ftir Analysis ◽

Excellent Thermal Stability ◽

X Ray ◽

Cone Calorimeter Test ◽

Before And After

Lyocell fabrics are widely applied in textiles, however, its high flammability increases the risk of fire. Therefore, to resolve the issue, a novel biomass-based flame retardant with phosphorus and nitrogen elements was designed and synthesized by the reaction of arginine with phosphoric acid and urea. It was then grafted onto the lyocell fabric by a dip-dry-cure technique to prepare durable flame-retardant lyocell fabric (FR-lyocell). X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) analysis demonstrated that the flame retardant was successfully introduced into the lyocell sample. Thermogravimetric (TG) and Raman analyses confirmed that the modified lyocell fabric featured excellent thermal stability and significantly increased char residue. Vertical combustion results indicated that FR-lyocell before and after washing formed a complete and dense char layer. Thermogravimetric Fourier-transform infrared (TG-FTIR) analysis suggested that incombustible substances (such as H2O and CO2) were produced and played a significant fire retarding role in the gas phase. The cone calorimeter test corroborated that the peak of heat release rate (PHRR) and total heat release (THR) declined by 89.4% and 56.4%, respectively. These results indicated that the flame retardancy of the lyocell fabric was observably ameliorated.

Download Full-text

Microstructural Studies of NiCoMnIn Magnetic Shape Memory Ribbons

Materials Science Forum ◽

10.4028/www.scientific.net/msf.738-739.436 ◽

2013 ◽

Vol 738-739 ◽

pp. 436-440 ◽

Cited By ~ 1

Author(s):

Krystian Prusik ◽

Katarzyna Bałdys ◽

Danuta Stróż ◽

Tomasz Goryczka ◽

Józef Lelątko

Keyword(s):

Melt Spinning ◽

Room Temperature ◽

Parent Phase ◽

Magnetic Shape Memory ◽

Melt Spun ◽

Columnar Grains ◽

Ebsd Technique ◽

Microstructural Studies ◽

Melt Spinning Technique ◽

Scanning Electron

In present paper two ribbons of the Ni44Co6Mn36In14 (at.%) were prepared under different melt-spinning technique conditions. Microstructure of the ribbons was studied by scanning electron microscopy (SEM). Depending on the liquid ejection overpressure two types of ribbons microstructures were observed. Ribbon T1 for which ejection overpressure was 1.5 bar showed typical melt-spun ribbon microstructure consisting of a top layer of small equi-axial grains and columnar grains below. For T2 ribbon (ejection overpressure 0.2 bar) only a small fraction of the columnar grains were observed. Structure analysis of the ribbons performed by XRD showed that at room temperature both ribbons have B2 parent phase superstructure. No gamma phase precipitates were observed. In order to determine the orientation of the grains the EBSD technique was applied.

Download Full-text

Ramie fiber reinforced composites with flame retardant structure design: flammability, smoke suppression, and mechanical properties

Journal of Polymer Engineering ◽

10.1515/polyeng-2021-0221 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Chenkai Zhu ◽

Lei Nie ◽

Xiaofei Yan ◽

Jiawei Li ◽

Dongming Qi

Keyword(s):

Shear Strength ◽

Iron Oxide ◽

Heat Release ◽

Flame Retardant ◽

Interlaminar Shear Strength ◽

Smoke Suppression ◽

Strength Analysis ◽

Ramie Fiber ◽

Composite Surface ◽

Interlaminar Shear

Abstract In this work, the structure of composite was designed as Core Stack and Surface Stack, which was treated with the expandable graphite (EG) and metal oxides such as iron oxide (IO), hydroxyapatite (HA), and aluminum tri-hydroxide (ATH). The mechanical performance of composites was characterized via flexural performance and interlaminar shear strength analysis. The flame retardance and smoke suppression of composite was explored in detail by LOI, UL-94, and cone calorimeter test. The findings presented that flexural properties of composites were observed to decrease due to delamination of surface stack, whilst no significant effect on interlaminar shear strength. In comparison with control composite, the loading of metal oxide into composite Surface Stack led to the reduction of peak heat release rate, total heat release, and fire growth index effectively. Moreover, the remarkable decrease in total smoke production could be observed due to the addition of iron oxide and the flame retardant mechanism was discussed. This study was the preliminary exploration of composite with flame retardant design which could be potential solution to improve flame retardancy and smoke suppression of composite with better mechanical structure preservation.

Download Full-text

Development of Inherently Flame—Retardant Phosphorylated PLA by Combination of Ring-Opening Polymerization and Reactive Extrusion

Materials ◽

10.3390/ma13010013 ◽

2019 ◽

Vol 13 (1) ◽

pp. 13 ◽

Cited By ~ 1

Author(s):

Rosica Mincheva ◽

Hazar Guemiza ◽

Chaimaa Hidan ◽

Sébastien Moins ◽

Olivier Coulembier ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Ring Opening ◽

Coupling Reaction ◽

Reactive Extrusion ◽

Ring Opening Polymerization ◽

Hexamethylene Diisocyanate ◽

Cone Calorimetry ◽

Loss Cone ◽

Ul 94

In this study, a highly efficient flame-retardant bioplastic poly(lactide) was developed by covalently incorporating flame-retardant DOPO, that is, 9,10-dihydro-oxa-10-phosphaphenanthrene-10-oxide. To that end, a three-step strategy that combines the catalyzed ring-opening polymerization (ROP) of L,L-lactide (L,L-LA) in bulk from a pre-synthesized DOPO-diamine initiator, followed by bulk chain-coupling reaction by reactive extrusion of the so-obtained phosphorylated polylactide (PLA) oligomers (DOPO-PLA) with hexamethylene diisocyanate (HDI), is described. The flame retardancy of the phosphorylated PLA (DOPO-PLA-PU) was investigated by mass loss cone calorimetry and UL-94 tests. As compared with a commercially available PLA matrix, phosphorylated PLA shows superior flame-retardant properties, that is, (i) significant reduction of both the peak of heat release rate (pHRR) and total heat release (THR) by 35% and 36%, respectively, and (ii) V0 classification at UL-94 test. Comparisons between simple physical DOPO-diamine/PLA blends and a DOPO-PLA-PU material were also performed. The results evidenced the superior flame-retardant behavior of phosphorylated PLA obtained by a reactive pathway.

Download Full-text