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Li F, Huang Z, Liu C, Yang M, Wu J, Rao W, Yu C. A novel P/N/Si/Zn-containing hybrid flame retardant for enhancing flame retardancy and smoke suppression of epoxy resins. RSC Adv 2024; 14:8204-8213. [PMID: 38469190 PMCID: PMC10926111 DOI: 10.1039/d4ra00166d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 03/05/2024] [Indexed: 03/13/2024] Open
Abstract
Currently, additively efficient flame retardants are being developed to enhance the smoke suppression, flame retardancy, and thermal properties of composite materials. To this end, the current study designed and prepared a novel P/N/Si/Zn-containing organic-inorganic hybrid denoted as APHZ. Its inorganic part was 2-methylimidazole zinc salt (ZIF-8), which improved its smoke suppression and catalytic carbonization. The organic part (P/N/Si-containing compound) promoted its flame retardancy and interfacial compatibility between APHZ and epoxy resin (EP). The test results revealed that EP/APHZ-3 composites achieved a V-0 rating and a notable LOI value of 30.7% when introducing 3 wt% APHZ into the EP matrix. Cone calorimetry tests (CCT) further demonstrated that the average heat release rate (av-HRR), total smoke production (TSP), and CO production (COP) of EP/APHZ-3 were reduced by 23.3%, 14.0%, and 21.1%, respectively. Meanwhile, the char residual was increased by 60.6%, as compared to pure EP. Furthermore, the flame-retardant mechanism of EP/APHZ composites was investigated by the XPS, TG-FTIR, and Raman spectroscopy techniques. The observed synergistic effect of the imidazole skeleton ZIF-8 and P/N/Si-containing compound in APHZ facilitated the generation of a dense multi-element char layer, with the condensed phase flame-retardant mechanism playing a dominant role. These findings contribute to developing and designing high-performance flame-retardant EP.
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Affiliation(s)
- Fangli Li
- Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials, Ministry of Education, College of Materials Science and Engineering, Guilin University of Technology (GUT) Guilin 541004 China
| | - Ziqin Huang
- Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials, Ministry of Education, College of Materials Science and Engineering, Guilin University of Technology (GUT) Guilin 541004 China
| | - Changjiang Liu
- Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials, Ministry of Education, College of Materials Science and Engineering, Guilin University of Technology (GUT) Guilin 541004 China
| | - Meini Yang
- Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials, Ministry of Education, College of Materials Science and Engineering, Guilin University of Technology (GUT) Guilin 541004 China
| | - Jixiang Wu
- Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials, Ministry of Education, College of Materials Science and Engineering, Guilin University of Technology (GUT) Guilin 541004 China
| | - Wenhui Rao
- Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials, Ministry of Education, College of Materials Science and Engineering, Guilin University of Technology (GUT) Guilin 541004 China
| | - Chuanbai Yu
- Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials, Ministry of Education, College of Materials Science and Engineering, Guilin University of Technology (GUT) Guilin 541004 China
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Liu C, Tao J, Wu T, Zhao HB, Yu C, Rao W. Construction of hierarchical SiO 2 microcapsule towards flame retardation, low toxicity and mechanical enhancement of epoxy resins. CHEMOSPHERE 2023; 342:140184. [PMID: 37716559 DOI: 10.1016/j.chemosphere.2023.140184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 09/10/2023] [Accepted: 09/13/2023] [Indexed: 09/18/2023]
Abstract
A novel approach for improving the flame retardancy, smoke suppression and mechanical properties of epoxy resins (EPs) has been proposed by incorporating functionalized hollow mesoporous silica microcapsules (SHP) loaded with phosphorous silane flame retardants (SCA) and coated with polydopamine (PDA) and transition metals. The proposed approach involves a multi-level structure that combines several mechanisms to enhance the flame-retardant properties of EP. The physical barrier provided by silica serves to impede heat and mass transfer during combustion, while the catalytic carbonization effect of phosphorus and transition metals promotes the formation of a protective char layer, which acts as a barrier to further flame propagation. Incorporating a low loading amount of 3 wt% SHP into the epoxy matrix resulted in EP/SHP-3 composites with significantly improved flame retardancy, as evidenced by a limiting oxygen index of 31.5% and a V-1 rating, in contrast to the values obtained for unmodified EP, which were 23.8% and no rating, respectively. In addition, cone calorimeter test (CCT) results indicated that the total heat release, peak heat release rate and total smoke production of EP/SHP-3 decreased by 18.2%, 25.2% and 18.4%, respectively. Moreover, the improved interfacial compatibility facilitated by polydopamine assists in the dispersion and compatibility of the SHP with the epoxy matrix, leading to better mechanical properties. Herein, the addition of 1 wt% SHP to EP significantly improved its mechanical performance, with a 16.7% increase in tensile strength and a 19.2% increase in impact strength. The design of the multi-level structural approach has the potential to provide new ideas for the simultaneous improvement of fire safety as well as mechanical properties of polymers.
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Affiliation(s)
- Changjiang Liu
- College of Materials Science and Engineering, Guilin University of Technology (GUT), Guilin, 541004, China
| | - Jie Tao
- College of Materials Science and Engineering, Guilin University of Technology (GUT), Guilin, 541004, China
| | - Tao Wu
- College of Materials Science and Engineering, Guilin University of Technology (GUT), Guilin, 541004, China
| | - Hai-Bo Zhao
- The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials (MoE), National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University, Chengdu, 610064, China
| | - Chuanbai Yu
- College of Materials Science and Engineering, Guilin University of Technology (GUT), Guilin, 541004, China.
| | - Wenhui Rao
- College of Materials Science and Engineering, Guilin University of Technology (GUT), Guilin, 541004, China.
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Huang Z, Li F, Huang M, Meng W, Rao W, Lei Y, Yu C. Preparation of Naphthalene-Based Flame Retardant for High Fire Safety and Smoke Suppression of Epoxy Resin. Molecules 2023; 28:molecules28114287. [PMID: 37298763 DOI: 10.3390/molecules28114287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 05/18/2023] [Accepted: 05/20/2023] [Indexed: 06/12/2023] Open
Abstract
One of the current challenges in the development of flame retardants is the preparation of an environmentally friendly multi-element synergistic flame retardant to improve the flame retardancy, mechanical performance, and thermal performance of composites. This study synthesized an organic flame retardant (APH) using (3-aminopropyl) triethoxysilane (KH-550), 1,4-phthalaadehyde, 1,5-diaminonaphthalene, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) as raw materials, through the Kabachnik-Fields reaction. Adding APH to epoxy resin (EP) composites could greatly improve their flame retardancy. For instance, UL-94 with 4 wt% APH/EP reached the V-0 rating and had an LOI as high as 31.2%. Additionally, the peak heat release rate (PHRR), average heat release rate (AvHRR), total heat release (THR), and total smoke produced (TSP) of 4% APH/EP were 34.1%, 31.8%, 15.2%, and 38.4% lower than EP, respectively. The addition of APH improved the mechanical performance and thermal performance of the composites. After adding 1% APH, the impact strength increased by 15.0%, which was attributed to the good compatibility between APH and EP. The TG and DSC analyses revealed that the APH/EP composites that incorporated rigid naphthalene ring groups had higher glass transition temperatures (Tg) and a higher amount of char residue (C700). The pyrolysis products of APH/EP were systematically investigated, and the results revealed that flame retardancy of APH was realized by the condensed-phase mechanism. APH has good compatibility with EP, excellent thermal performance, enhanced mechanical performance and rational flame retardancy, and the combustion products of the as-prepared composites complied with the green and environmental protection standards which are also broadly applied in industry.
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Affiliation(s)
- Ziqin Huang
- College of Materials Science and Engineering, Guilin University of Technology (GUT), Guilin 541004, China
| | - Fangli Li
- College of Materials Science and Engineering, Guilin University of Technology (GUT), Guilin 541004, China
| | - Mingyan Huang
- College of Materials Science and Engineering, Guilin University of Technology (GUT), Guilin 541004, China
| | - Wenqiao Meng
- College of Materials Science and Engineering, Guilin University of Technology (GUT), Guilin 541004, China
| | - Wenhui Rao
- College of Materials Science and Engineering, Guilin University of Technology (GUT), Guilin 541004, China
| | - Yuan Lei
- China Antimony Corporation, Nanning 530001, China
| | - Chuanbai Yu
- College of Materials Science and Engineering, Guilin University of Technology (GUT), Guilin 541004, China
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Song K, Zhang H, Pan YT, Ur Rehman Z, He J, Wang DY, Yang R. Metal-organic framework-derived bird's nest-like capsules for phosphorous small molecules towards flame retardant polyurea composites. J Colloid Interface Sci 2023; 643:489-501. [PMID: 37088052 DOI: 10.1016/j.jcis.2023.04.047] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/29/2023] [Accepted: 04/12/2023] [Indexed: 04/25/2023]
Abstract
The loading treatment of phosphorus flame retardants can mitigate their migration and plasticization effect. However, designing suitable carriers has remained a great challenge. Herein, two kinds of Co-based isomers, namely cobalt-cobalt layered double hydroxides (CoCo-LDH) and cobalt basic carbonate (CBC), were synthesized by employing ZIF-67 as a self-template, assemblied into two different nanostructures namely multi-yolk@shell CBC@CoCo-LDH (m-CBC@LDH) and solid CBC nanoparticles by facilely tuning the reaction time, which were employed as carriers, respectively. Subsequently, triphenyl phosphate (TPP)-loaded m-CBC@LDH (m-CBC-P@LDH) was prepared using TPP as the guest. The m-CBC@LDH with high specific surface area and hollow structure exhibited up to more than 30% of TPP loading. The peak of heat release rate and total heat release of polyurea composite blended with 5 wt% m-CBC-P@LDH reduced by 41.7% and 20.6% respectively, and the mechanical properties were less damaged. This work complements a feasible approach for preparation of metal-organic frameworks-derived flame retardant carriers.
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Affiliation(s)
- Kunpeng Song
- National Engineering Research Center of Flame Retardant Materials, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, PR China
| | - Henglai Zhang
- National Engineering Research Center of Flame Retardant Materials, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, PR China
| | - Ye-Tang Pan
- National Engineering Research Center of Flame Retardant Materials, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, PR China.
| | - Zeeshan Ur Rehman
- College of Mechatronic Engineering, Changwon National University, Changwon, Gyeongsangnam-do 51140, Republic of Korea
| | - Jiyu He
- National Engineering Research Center of Flame Retardant Materials, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, PR China.
| | - De-Yi Wang
- IMDEA Materials Institute, C/Eric Kandel, 2, 28906 Getafe, Madrid, Spain
| | - Rongjie Yang
- National Engineering Research Center of Flame Retardant Materials, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing 100081, PR China
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Hu P, Li W, Huang S, Zhang Z, Liu H, Zhan W, Chen M, Kong Q. Effect of Layered Aminovanadic Oxalate Phosphate on Flame Retardancy of Epoxy Resin. Molecules 2023; 28:molecules28083322. [PMID: 37110556 PMCID: PMC10142990 DOI: 10.3390/molecules28083322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 03/31/2023] [Accepted: 04/07/2023] [Indexed: 04/29/2023] Open
Abstract
To alleviate the fire hazard of epoxy resin (EP), layered ammonium vanadium oxalate-phosphate (AVOPh) with the structural formula of (NH4)2[VO(HPO4)]2(C2O4)·5H2O is synthesized using the hydrothermal method and mixed into an EP matrix to prepare EP/AVOPh composites. The thermogravimetric analysis (TGA) results show that AVOPh exhibits a similar thermal decomposition temperature to EP, which is suitable for flame retardancy for EP. The incorporation of AVOPh nanosheets greatly improves the thermal stability and residual yield of EP/AVOPh composites at high temperatures. The residue of pure EP is 15.3% at 700 °C. In comparison, the residue of EP/AVOPh composites is increased to 23.0% with 8 wt% AVOPh loading. Simultaneously, EP/6 wt% AVOPh composites reach UL-94 V1 rating (t1 + t2 =16 s) and LOI value of 32.8%. The improved flame retardancy of EP/ AVOPh composites is also proven by the cone calorimeter test (CCT). The results of CCT of EP/8 wt% AVOPh composites show that the peak heat release rate (PHHR), total smoke production (TSP), peak of CO production (PCOP), and peak of CO2 production (PCO2P) decrease by 32.7%, 20.4%, 37.1%, and 33.3% compared with those of EP, respectively. This can be attributed to the lamellar barrier, gas phase quenching effect of phosphorus-containing volatiles, the catalytic charring effect of transition metal vanadium, and the synergistic decomposition of oxalic acid structure and charring effect of phosphorus phase, which can insulate heat and inhibit smoke release. Based on the experimental data, AVOPh is expected to serve as a new high-efficiency flame retardant for EP.
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Affiliation(s)
- Po Hu
- School of Emergency Management, Jiangsu University, Zhenjiang 212013, China
| | - Weixi Li
- School of Emergency Management, Jiangsu University, Zhenjiang 212013, China
| | - Shuai Huang
- School of Emergency Management, Jiangsu University, Zhenjiang 212013, China
| | - Zongmian Zhang
- School of Emergency Management, Jiangsu University, Zhenjiang 212013, China
| | - Hong Liu
- School of Emergency Management, Jiangsu University, Zhenjiang 212013, China
| | - Wang Zhan
- School of Emergency Management, Jiangsu University, Zhenjiang 212013, China
| | - Mingyi Chen
- School of Emergency Management, Jiangsu University, Zhenjiang 212013, China
| | - Qinghong Kong
- School of Emergency Management, Jiangsu University, Zhenjiang 212013, China
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Design of P-decorated POSS towards flame-retardant, mechanically-strong, tough and transparent epoxy resins. J Colloid Interface Sci 2023; 640:864-876. [PMID: 36907147 DOI: 10.1016/j.jcis.2023.03.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 03/01/2023] [Accepted: 03/02/2023] [Indexed: 03/09/2023]
Abstract
Epoxy resins (EPs) are known for their durability, strength, and adhesive properties, which make them a versatile and popular material for use in a variety of applications, including chemical anticorrosion, small electronic devices, etc. However, EP is highly flammable due to its chemical nature. In this study, phosphorus-containing organic-inorganic hybrid flame retardant (APOP) was synthesized by introducing 9, 10-dihydro-9-oxa-10‑phosphaphenathrene (DOPO) into cage-like octaminopropyl silsesquioxane (OA-POSS) via Schiff base reaction. The improved flame retardancy of EP was achieved by combining the physical barrier of inorganic Si-O-Si with the flame-retardant capability of phosphaphenanthrene. EP composites containing 3 wt% APOP passed the V-1 rating with a value of LOI of 30.1% and showed an apparent reduction in smoke release. Additionally, the combination of the inorganic structure and the flexible aliphatic segment in the hybrid flame retardant provides EP with molecular reinforcement, while the abundance of amino groups facilitates a good interface compatibility and outstanding transparency. Accordingly, EP containing 3 wt% APOP increased in tensile strength, impact strength, and flexural strength by 66.0 %, 78.6 %, and 32.3 %, respectively. The EP/APOP composites had a bending angle lower than 90°, and their successful transition to a tough material highlights the potential of this innovative combination of the inorganic structure and the flexible aliphatic segment. In addition, the relevant flame-retardant mechanism revealed that the APOP promoted the formation of a hybrid char layer containing P/N/Si for EP and produced phosphorus-containing fragments during combustion, showing flame-retardant effects in both condensed and vapor phases. This research offers innovative solutions for reconciling flame retardancy & mechanical performances and strength & toughness for polymers.
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Jia XW, Mu WL, Shao ZB, Xu YJ. Flame-Retardant Cycloaliphatic Epoxy Systems with High Dielectric Performance for Electronic Packaging Materials. Int J Mol Sci 2023; 24:ijms24032301. [PMID: 36768624 PMCID: PMC9916824 DOI: 10.3390/ijms24032301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 01/26/2023] Open
Abstract
Flame-retardant cycloaliphatic epoxy systems have long been studied; however, the research suffers from slow and unsatisfactory advances. In this work, we synthesized a kind of phosphorus-containing difunctional cycloaliphatic epoxide (called BCEP). Then, triglycidyl isocyanurate (TGIC) was mixed with BCEP to achieve epoxy systems that are rich in phosphorus and nitrogen elements, which were cured with 4-methylhexahydrobenzene anhydride (MeHHPA) to obtain a series of flame-retardant epoxy resins. Curing behaviors, flame retardancy, thermal behaviors, dielectric performance, and the chemical degradation behaviors of the cured epoxy system were investigated. BCEP-TGIC systems showed a high curing activity, and they can be efficiently cured, in which the incorporation of TGIC decreased the curing activity of the resin. As the ratio of BCEP and TGIC was 1:3, the cured resin (BCEP1-TGIC3) showed a relatively good flame retardancy with a limiting oxygen index value of 25.2%. In the cone calorimeter test, they presented a longer time to ignition and a lower heat release than the commercially available cycloaliphatic epoxy resins (ERL-4221). BCEP-TGIC systems presented good thermal stability, as the addition of TGIC delayed the thermal weight loss of the resin. BCEP1-TGIC3 had high dielectric performance and outperformed ERL-4221 over a frequency range of 1 HZ to 1 MHz. BCEP1-TGIC3 could achieve degradation under mild conditions in an alkali methanol/water solution. Benefiting from the advances, BCEP-TGIC systems have potential applications as electronic packaging materials in electrical and electronic fields.
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Bao Q, He R, Liu Y, Wang Q, Zhang C. Functionalized halloysite nanotubes endowing epoxy resin with simultaneously enhanced flame retardancy and mechanical properties. Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2022.111797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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