scholarly journals Development of Bioepoxy Resin Microencapsulated Ammonium-Polyphosphate for Flame Retardancy of Polylactic Acid

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4123 ◽  
Author(s):  
Kata Decsov ◽  
Katalin Bocz ◽  
Beáta Szolnoki ◽  
Serge Bourbigot ◽  
Gaëlle Fontaine ◽  
...  

Ammonium-polyphosphate (APP) was modified by microencapsulation with a bio-based sorbitol polyglycidyl ether (SPE)-type epoxy resin and used as a flame retardant additive in polylactic acid (PLA) matrix. The bioresin-encapsulated APP (MCAPP) particles were characterized using Fourier transform infrared (FTIR) spectroscopy and Raman mapping, particle size distribution was determined by processing of scanning electron microscopic (SEM) images. Interaction between the APP core and the bioresin shell was revealed by combined thermogravimetric analysis (TGA)‑FTIR spectroscopy. The APP to SPE mass ratio of 10 to 2 was found to be optimal in terms of thermal, flammability, and mechanical properties of 15 wt% additive containing biocomposites. The bioresin shell effectively promotes the charring of the APP-loaded PLA composites, as found using TGA and cone calorimetry, and eliminates the flammable dripping of the specimens during the UL-94 vertical burning tests. Thus, the V-0 rating, the increased limiting oxygen index, and the 20% reduced peak of the heat release rate was reached compared to the effects of neat APP. Furthermore, better interfacial interaction of the MCAPP with PLA was indicated by differential scanning calorimetry and SEM observation. The stiff interphase resulted in increased modulus of these composites. Besides, microencapsulation provided improved water resistance to the flame retardant biopolymer system.

2019 ◽  
Vol 37 (4-6) ◽  
pp. 434-451 ◽  
Author(s):  
Jonathan Almirón ◽  
Francine Roudet ◽  
Sophie Duquesne

This research determines whether the materials of volcanic ash (CV), rice husk ash (CR), and thermally treated solid waste (RS-T), coming from the pyrolysis of plastics, have some flame-retardant effect when added to polypropylene flame-retardant additives (such as ammonium polyphosphate and pentaerythritol). These materials were characterized by specific surface area by nitrogen adsorption analysis (Brunauer–Emmett–Teller) and X-ray fluorescence and X-ray diffraction methods. It was determined that SiO2 and Al2O3 are considered as flame-retardant minerals. Composites composed of polypropylene, ammonium polyphosphate, pentaerythritol, and these materials at several concentrations, from 1% to 9%, were prepared. The thermal stability and flame retardancy of the composites synthesized were investigated based on the limiting oxygen index, thermogravimetric analysis, and cone calorimetry. It was determined that these materials have a synergistic action with flame-retardant additives by increasing the fireproof properties of polypropylene. Mechanical properties were determined by tensile tests.


Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1513 ◽  
Author(s):  
Maqsood ◽  
Langensiepen ◽  
Seide

The objective of this study is to assess the efficiency of biobased carbonization agent in intumescent formulations (IFRs) to examine the flame retardant properties of polylactic acid (PLA) composites and to investigate their melt-spinnability. We used phosphorous-based halogen free flame retardant (FR) and kraft lignin (KL) as bio-based carbonization agent. After melt compounding and molding into sheets by hot pressing various fire related characteristics of IFR composites were inspected and were characterized by different characterization methods. It was fascinating to discover that the introduction of 5−20 wt% FR increased the limiting oxygen index (LOI) of PLA composites from 20.1% to 23.2−33.5%. The addition of KL with content of 3−5 wt% further increased the LOI up to 36.6−37.8% and also endowed PLA/FR/KL composites with improved anti-dripping properties. 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%. For comparative study, IFR composites containing pentaerythritol (PER) as a carbonization agent were also prepared and their FR properties were compared. IFR composites were melt spun and mechanical properties of multifilament yarns were tested. The analysis of char residues by energy dispersive X-ray spectrometry (EDS) and SEM images confirmed that PLA/FR/KL composites developed a thicker and more homogeneous char layer with better flame retardant properties confirming that the fire properties of PLA can be enhanced by using KL as a carbonization agent.


2018 ◽  
Vol 31 (1) ◽  
pp. 86-96 ◽  
Author(s):  
R Vini ◽  
S Thenmozhi ◽  
SC Murugavel

In this study, azomethine polyphosphonates were synthesized by solution polycondensation of phenylphosphonic dichloride with various azomethine diols such as [4-(4-hydroxy phenyl) iminomethyl] phenol, [(4-(4-hydroxy-3-methoxy phenyl) iminomethyl)] phenol and [4-(4-hydroxy-3-ethoxy phenyl) iminomethyl] phenol using triethylamine catalyst at ambient temperature. The structure of the synthesized polymers was confirmed by Fourier transform infrared and 1H-, 13C- and 31P- nuclear magnetic resonance spectroscopic techniques. Thermal properties of the polymers were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry under nitrogen atmosphere. The TGA data showed that the synthesized polyphosphonates produce high char yield at 600°C due to the presence of phosphorous atom in the polymer chain and hence have good flame-retardant properties. One of the synthesized polyphosphonate was blended with commercial diglycidyl ether of bisphenol-A (DGEBA) resin in various weight percentage and cured with commercial curing agent triethylene tetramine (TETA). The polyphosphonates-blended epoxy thermosets have tensile strength in the range of 5–41 MPa and the percentage of elongation at breaks was 4–18. It was found that the incorporation of polyphosphonates into epoxy thermoset decreased the tensile strength from 41 MPa to 5 MPa, whereas the elongation at break value increased with increase in the weight percentage of polyphosphonate. The influence of polyphosphonates on the flame retardancy of blended thermosets was examined by limiting oxygen index (LOI) and vertical burning (UL-94) tests and found that the polymer samples achieved an increased UL-94 rating and the LOI values were in the range of 24–26. Broido and Horowitz–Metzger methods have been used to study the thermal degradation kinetic parameters.


Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1575
Author(s):  
Huong Nguyen Thi ◽  
Khanh Vu Thi Hong ◽  
Thanh Ngo Ha ◽  
Duy-Nam Phan

Cotton fabric treated by Pyrovatex CP New (PCN) and Knittex FFRC (K-FFRC) using the Pad-dry-cure method showed an excellent fire-retardant effect. However, it needed to be cured at high temperatures for a long time leading to a high loss of mechanical strength. In this study, atmospheric-pressure dielectric barrier discharge (APDBD) plasma was applied to the cotton fabric, which then was treated by flame retardants (FRs) using the pad–dry-cure method. The purpose was to have a flame-retardant cotton fabric (limiting oxygen index (LOI) ≥ 25) and a mechanical loss of the treated fabric due to the curing step as low as possible. To achieve this goal, 10 experiments were performed. The vertical flammability characteristics, LOI value and tensile strength of the treated fabrics were measured. A response model between the LOI values of the treated fabric and two studied variables (temperature and time of the curing step) was found. It was predicted that the optimal temperature and time-to-cure to achieve LOI of 25 was at 160 °C for 90 s, while the flame-retardant treatment process without plasma pretreatment, was at 180 °C and 114 s. Although the curing temperature and the time have decreased significantly, the loss of mechanical strength of the treated fabric is still high. The tensile strength and scanning electron microscopy (SEM) images of the fabric after plasma activation show that the plasma treatment itself also damages the mechanical strength of the fabric. X-ray photoelectron spectroscopy (XPS) spectra of the fabric after plasma activation and energy-dispersive spectroscopy (EDS) analysis of the flame retardant-treated (FRT) fabric clarified the role of plasma activation in this study.


2020 ◽  
Vol 842 ◽  
pp. 16-21
Author(s):  
Wei Ying Gao

In our previous work, ammonium polyphosphate (APP) microcapsule with the shell of boron modified phenolic resin (BPF) was prepared, recorded as BPFAPP. However, the compatibility and the flame retardancy of BPFAPP in thermoplastic polyurethane elastomer (TPU) are still not very good due to the brittle and hard shell wall. To improve the brittleness of microcapsules shell and the property reinforcements of APP in TPU, APP was encapsulated with the tung oil and boron modified phenolic resin (TBPF) in this paper, recorded as TBPFAPP. The property reinforcements of TBPFAPP in TPU were studied. The thermogravimetry, limiting oxygen index and cone calorimetry analysis showed that TPU/TBPFAPP composite had higher char yield and better flame resistance. The tensile strength and elongation at break showed that the mechanical properties were also significantly improved due to the introduction of α-Eleostearate.


2009 ◽  
Vol 4 (2) ◽  
pp. 155892500900400 ◽  
Author(s):  
Christelle Reti ◽  
Mathilde Casetta ◽  
Sophie Duquesne ◽  
René Delobel ◽  
Jérémie Soulestin ◽  
...  

The work focuses on the development of a new process to flame retard nonwovens, using films based on renewable resources. Films consist in intumescent formulations of polylactic acid (PLA), ammonium polyphosphate (APP) blended with lignin or starch and are coated on hemp or wool nonwovens. The objective of this study was to investigate the fire retardant and mechanical properties of textiles protected by FR PLA films for potential use in building applications. Horizontal and vertical flame spread tests as well as cone calorimetry tests show that flammability properties of nonwovens are significantly improved. Better mechanical properties are also obtained with coated nonwovens.


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 778 ◽  
Author(s):  
Jacob Sag ◽  
Philipp Kukla ◽  
Daniela Goedderz ◽  
Hendrik Roch ◽  
Stephan Kabasci ◽  
...  

Novel polymeric acrylate-based flame retardants (FR 1–4) containing two phosphorus groups in different chemical environments were synthesized in three steps and characterized via nuclear magnetic resonance (NMR) spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and mass spectrometry (MS). Polylactic acid (PLA) formulations with the synthesized compounds were investigated to evaluate the efficiency of these flame retardants and their mode of action by using TGA, UL94, and cone calorimetry. In order to compare the results a flame retardant polyester containing only one phosphorus group (ItaP) was also investigated in PLA regarding its flame inhibiting effect. Since the fire behavior depends not only on the mode of action of the flame retardants but also strongly on physical phenomena like melt dripping, the flame retardants were also incorporated into PLA with higher viscosity. In the UL94 vertical burning test setup, 10% of the novel flame retardants (FR 1–4) is sufficient to reach a V-0 rating in both PLA types, while a loading of 15% of ItaP is not enough to reach the same classification. Despite their different structure, TGA and cone calorimetry results confirmed a gas phase mechanism mainly responsible for the highly efficient flame retardancy for all compounds. Finally, cone calorimetry tests of the flame retardant PLA with two heat fluxes showed different flame inhibiting efficiencies for different fire scenarios.


2020 ◽  
Vol 977 ◽  
pp. 102-107
Author(s):  
Yu Lei Zheng ◽  
Shuang Chen ◽  
Jia Hui Wang ◽  
Ru Xiao

Polyamide 66 (PA66) benefits from excellent mechanical properties and good chemical resistance, which enabled wide application of this material in various industrial fields; however, it suffers from high flammability. Generally, preparation of a flame retardant PA from a reactive flame retardant involves a two-step process. In this study, the flame retardant PA66s (FRPA66s) are synthesized via a one-pot melt copolycondensation route by using a reactive phosphorus-containing flame retardant (FR-B). Then, molecular weight, some mechanical and thermal properties along with flame retardant properties of FRPA66s were investigated by gel permeation chromatography (GPC), instron material testing, differential scanning calorimetry (DSC), thermogravimetry (TG) analysis, vertical burning test (UL 94), and limiting oxygen index test (LOI) techniques. The experimental results confirmed that FRPA66s synthesized by the one-pot method have very similar properties compared to those obtained via the two-step process. Moreover, the prepared materials showed good non-flammability behavior with limiting oxygen index value of over 30% and a vertical burning test result of V-0 rating.


Sign in / Sign up

Export Citation Format

Share Document