Synthesis of Cobalt Borate Compound to Confer Fire-proof Properties to Epoxy-Based Composites by Achieving Synergistic Effect with Red Phosphorus

Abstract

This study investigated the synergistic effect of a cobalt borate (CoB) compound synthesized by molten-salt-assisted borothermal reduction on epoxy resins, both alone and in combination with red phosphorus (RP) flame-retardant additives, on flame-retardancy. In the first stage of the research, the CoB compound was synthesized using a molten salt-assisted borothermal method, yielding Co3B2O6 at 750°C. X-ray diffraction (XRD), scanning electron microscopy equipped with energy dispersive x-ray spectroscopy (SEM-EDX), thermogravimetric analysis (TGA), and fourier transform infrared (FTIR) spectroscopy were used to characterize the synthesized compound. The synthesized CoB compound was first tested alone at varying weight ratios to investigate its flammability. Subsequently, it was used in combination with a RP-containing flammability additive, and its synergistic interactions were evaluated using UL- 94, limiting oxygen index (LOI), and cone calorimeter tests. The flammability tests showed that the combination containing 1% CoB and 9% RP demonstrated the highest resistance to combustion. In this sample, a V0 rating was achieved in the UL-94 vertical test; LOI increased by 1.5-2.0 units compared to the additive-free epoxy, and the heat release rate (HRR) was approximately 30% lower in the calorimeter test compared to the additive-free epoxy resin.

Keywords

• Epoxy resin
• Red phosphorus
• Cobalt borate
• Metal borate synthesis
• Flame retardancy

Supporting Institution

Bartın University Project Technology Office

Project Number

2021K12-169131/06

Ethical Statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper

Thanks

This study was financially supported by Bartın University Project Technology Office within the scope of the Regional Development Projects with project number 2021K12-169131/06

Kobalt Borat Bileşiğinin Sentezlenmesi ve Kırmızı Fosfor ile Sinerjik Etki Sağlanarak Epoksi Esaslı Kompozitlere Yanmazlık Özelliğinin Kazandırılması

Abstract

Çalışma kapsamında erimiş tuz destekli borotermal indirgeme yöntemiyle sentezlenen kobalt borat bileşiğinin, epoksi reçinelerinde tek başına kullanıldığında güç tutuşurluk etkinliğine ek olarak, kırmızı fosfor yanmazlık eklentisi ile sinerjik etkinliği araştırılmıştır. Araştırmanın ilk aşamasında, kobalt borat bileşiğinin sentez işlemi, kobalt metalin tuzu ve borik asit türevleri kullanılarak sulu ortamda otoklav içinde 240oC sıcaklıkta sıcaklık-katı reaksiyonla üretilme yöntemi ile gerçekleştirilmiştir. Sentezlenen bileşiğin karakterize edilmesinde X-ışını analizi (XRD), SEM-EDX analizi, termogravimetrik analiz (TGA) ve Fourier dönüşümlü kızılötesi ışın (FTIR) spektroskopisi kullanılmıştır. Sentezi gerçekleştirilen Co3B2O6 bileşiği, öncelikle tek başına ağırlıkça değişik oranlarda kullanılarak güç tutuşurluk etkileri incelenmiş olup, daha sonraki aşamada ise kırmızı fosfor içeren güç tutuşurluk eklentisi ile birlikte kullanılarak sinerjik etkileşimleri UL-94, sınırlayıcı oksijen indisi (LOI) ve konik kalorimetre testleri ile değerlendirilmiştir. Yanmazlık testleri sonucunda, %1 oranında kobalt borat ile %9 oranında kırmızı fosfor içeren kombinasyon, yanmaya karşı direnç açısından ön plana çıkmıştır. Bu numunede, UL-94 dikey testinde V0 değerine ulaşılmış, sınırlayıcı oksijen indisi (LOI) değerinde eklentisiz epoksiye kıyasla 1,5-2,0 birim artış olup kalorimetre testinde eklentisiz epoksiye göre %30 civarında daha düşük ısı salınım miktarı (HRR) gözlenmiştir.

Keywords

• Epoksi reçine
• Kırmızı fosfor
• Kobalt borat
• Metal borat sentezi
• Yanmazlık

Supporting Institution

Bartın Üniversitesi Proje Teknoloji Ofisi

Project Number

2021K12-169131/06

Ethical Statement

Yazarlar, bu makalede bildirilen çalışmayı etkilemiş olabilecek bilinen herhangi bir çıkar çatışması veya kişisel ilişkiye sahip olmadıklarını beyan etmektedir.

Thanks

Bu çalışma, Bartın Üniversitesi Proje Teknoloji Ofisi tarafından Bölgesel Kalkınma Projeleri kapsamında 2021K12-169131/06 proje numarasıyla mali olarak desteklenmiştir.

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