An Itaconic Acid‐Based Phosphorus‐Containing Oligomer Endowing Epoxy Resins with Good Flame Retardancy and Toughness

Abstract

With the aim to reduce the influence of flammability and brittleness of epoxy resin (EP) on its applications, a phosphorus-containing oligomer (BID) containing phosphophenanthrene group and flexible chain segment is designed and applied to methyltetrahydrophthalic anhydride (MeTHPA) curing EP systems. Compared with EP/MeTHPA, the glass transition temperature (T g ) declines after introducing BID. But the addition of BID endows EP/MeTHPA with good flame retardancy. When the dosage is only 19.2 wt.%, the limiting oxygen index (LOI) of EP/BID/MeTHPA increases by 77% to 36% (P content: 1.5 wt.%) compared with EP and reaches the vertical combustion (UL-94) V-0 rating. Cone calorimetry (CC) results reveal that PHRR and THR drop by 40% and 31%. The pyrolytic process and char residue data analysis show that BID plays flame-retardant role in gas phase and condensed phase. In addition, impact and flexural and tensile strength improve by 84%, 19% and 54% individually, proving that BID holds a potential on enhancing mechanical performance of EP/MeTHPA.

3D Printed All‐Natural Hydrogels: Flame‐Retardant Materials Toward Attaining Green Sustainability

“…h) TGA and i) derivative thermogravimetry (DTG) curves of the dried hydrogels. j) Comparison of the limited oxygen index of all-natural hydrogels with various biomass-based hydrogels: calcium alginate/poly(vinyl alcohol)/graphite (CA/PVA/EG), [38] sodium alginate/PNIPAAm/polyvinyl alcohol (SA/PNIPAAm/PVA), [3] itaconic acid/epoxy resins/methyltetrahydrophthalic anhydride (IA/EP/MeTHPA), [39] sodium alginate/poly(acroleic acid-acrylamide)/sodium chloride (SA/P(AA-AM)/NaCl), [40] sodium alginate/agar/boric acid (SA/GA/BA), [41] chitosan/sodium alginate (CH/SA). [42] Apparent topography recorded with k) AFM and l) optical microscope (magnification of 40) on the outer surface of IAE/GEV/SAV hydrogels.…”

“…Compared with the published work, in general, the as-prepared biomass-based hydrogels were designed to crosslink with at least one of our three components. [3,[38][39][40][41][42] Our fully biomass-based hydrogels have significant advantages in limiting oxygen index, implying their outstanding flame performance (Figure 2j). This beneficial phenomenon can be attributed not only to the synergistic flame-retarded effects of IAE, GEV, and SAV components but also to the peculiar manufacturing pattern: LCD 3D printing.…”

The synthesis of biphenyl ether/vanillin‐based flame retardants for enhancing both the flame retardant properties and mechanical performance of epoxy resin

“…In the development of the composite materials industry, epoxy resin (EP) is widely used in industries such as machinery, automotive, electronics, electrical, aerospace, due to its excellent chemical resistance, adhesion, insulation, dimensional stability, and flexible and convenient molding process. 1,2 However, the limiting oxygen index (LOI) of EP is 20%-26%, making it prone to combustion in air with a fast flame spread rate. 3 This potential fire hazard greatly limits the application of EP in high flame retardant requirement fields.…”

“…into the EP system can improve the toughness of EP. 2,[18][19][20][21][22] Meanwhile, most modified EP raw materials are nonrenewable, which is not conducive to green environment and sustainable resource development. 23 Moreover, people are increasingly paying attention to the preparation of flame-retardant EP thermosetting materials from biological resources, which has been reflected in many studies, including vanillin (VA), cashew phenols, soybean glycosides, eugenol, magnolol, and itaconic acid.…”

“…23 Moreover, people are increasingly paying attention to the preparation of flame-retardant EP thermosetting materials from biological resources, which has been reflected in many studies, including vanillin (VA), cashew phenols, soybean glycosides, eugenol, magnolol, and itaconic acid. 2,[24][25][26][27][28][29][30] Wang et al 31 prepared phytic acid (PA) derived flame retardant (PAPDOPO) using PA as raw material, and the modified resin system exhibited good flame retardancy. Compared with pure EP, the peak heat release rate of EP-PAPD-4 decreased by 30.4%.…”