Effects of post cure treatment in the glass transformation range on the structure and fire behavior of in situ generated silica/epoxy hybrids

Bifulco, Aurelio; Tescione, F.; Capasso, Agostino; Mazzei, Pierluigi; Piccolo, Alessandro; Durante, Massimo; Lavorgna, Marino; Malucelli, Giulio; Branda, F.

doi:10.1007/s10971-018-4710-2

Cited by 23 publications

(53 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The flammability of all the studied systems was tested through UL94 vertical spread test. All the samples (i.e., DGEBA/MNA, DGEBA/MNA_2Si, BOMF/MNA and BOMF/MNA_2Si) resulted as being not classifiable according to the UL94 vertical spread test, because it was not possible to prevent the flame propagation along the sample, as already observed for DGEBA cured with polyamines (PAs) [15]. However, a strong influence of the use of the anhydride hardener on the combustion behavior and, in the case of the DGEBA/MNA system, of silica addition was observed.…”

Section: Flame Retardant Behaviormentioning

confidence: 84%

“…The in-situ formation of the silicate phase required a temperature of 80 • C and reflux conditions. The synthesis procedure was modified and inspired by methodologies reported in the literature [15,22].…”

Section: Preparation Of the Epoxy Resins And Epoxy/silica Hybrid Nanomentioning

confidence: 99%

“…Due to the significantly lower viscosity of BOMF, compared to DGEBA, indeed, a more significant molecular motion is allowed, leading to the formation bigger silica clusters. It's worth underlining that the synthesis strategy of the present work, described in the experimental section, is similar to the one adopted in a previous paper [15] but differs for the final curing step (i.e., step 3, for which DGEBA was cured with polyamines for 4 h at 80 • C). However, in any case, performing the sol-gel method allows nanocomposites with a nanometric distribution of silica nanoparticles to be obtained.…”

Section: Morphology and Structure Of The Obtained Hybrid Systemsmentioning

confidence: 99%

“…Furthermore, the sol-gel process allows the interface between organic and inorganic phases to be tailored through the adequate selection of both the silane precursors of the inorganic phase and the sol-gel reaction conditions [12][13][14]. The silicate phase may act as a thermal protective layer and reinforcement for the epoxy matrix, improving its mechanical and flame retardant behavior [15,16].…”

Section: Introductionmentioning

confidence: 99%

“…In this context, using a sol-gel hybrid strategy for the synthesis of silica/BOMF nanocomposites cured with anhydrides may allow green materials to be obtained with satisfactory mechanical and flame retardant properties. In contrast to the phenyl analogs [12,13,15], only few papers have investigated the structure-properties relationships in hybrid furan-based materials [24,25].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Thermal and Fire Behavior of a Bio-Based Epoxy/Silica Hybrid Cured with Methyl Nadic Anhydride

et al. 2020

Self Cite

View full text Add to dashboard Cite

Thermosetting polymers have been widely used in many industrial applications as adhesives, coatings and laminated materials, among others. Recently, bisphenol A (BPA) has been banned as raw material for polymeric products, due to its harmful impact on human health. On the other hand, the use of aromatic amines as curing agents confers excellent thermal, mechanical and flame retardant properties to the final product, although they are toxic and subject to governmental restrictions. In this context, sugar-derived diepoxy monomers and anhydrides represent a sustainable greener alternative to BPA and aromatic amines. Herein, we report an “in-situ” sol–gel synthesis, using as precursors tetraethylorthosilicate (TEOS) and aminopropyl triethoxysilane (APTS) to obtain bio-based epoxy/silica composites; in a first step, the APTS was left to react with 2,5-bis[(oxyran-2-ylmethoxy)methyl]furan (BOMF) or diglycidyl ether of bisphenol A (DGEBA)monomers, and silica particles were generated in the epoxy in a second step; both systems were cured with methyl nadic anhydride (MNA). Morphological investigation of the composites through transmission electron microscopy (TEM) demonstrated that the hybrid strategy allows a very fine distribution of silica nanoparticles (at nanometric level) to be achieved within a hybrid network structure for both the diepoxy monomers. Concerning the fire behavior, as assessed in vertical flame spread tests, the use of anhydride curing agent prevented melt dripping phenomena and provided high char-forming character to the bio-based epoxy systems and their phenyl analog. In addition, forced combustion tests showed that the use of anhydride hardener instead of aliphatic polyamine results in a remarkable decrease of heat release rate. An overall decrease of the smoke parameters, which is highly desirable in a context of greater fire safety was observed in the case of BOMF/MNA system. The experimental results suggest that the effect of silica nanoparticles on fire behavior appears to be related to their dispersion degree.

show abstract

Section: Flame Retardant Behaviormentioning

confidence: 84%

Section: Preparation Of the Epoxy Resins And Epoxy/silica Hybrid Nanomentioning

confidence: 99%

Section: Morphology and Structure Of The Obtained Hybrid Systemsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Thermal and Fire Behavior of a Bio-Based Epoxy/Silica Hybrid Cured with Methyl Nadic Anhydride

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

Flame retarded polymer systems based on the sol-gel approach: recent advances and future perspectives

Bifulco

Imparato

Aronne

et al. 2022

J Sol-Gel Sci Technol

Self Cite

View full text Add to dashboard Cite

The ease of flammability of polymers represents a key issue that limits their applications in different advanced sectors. In this context, a reliable and effective solution regards the use of flame retardants, i.e., additives that are able to slow down (or even stop) the flame propagation and to enhance the resistance to an irradiative heat flux. Among the different flame retardants designed, synthesized, and applied up-to-now, the utilization of inorganic particles, inorganic and hybrid organic-inorganic coatings has gathered a great interest from either the academic and industrial community, as these structures can provide remarkable flame retardant features to different polymer systems, in which they are embedded or applied onto. In particular, the in situ generation (through sol-gel processes, i.e. hydrolysis and condensation reactions from tailored alkoxide precursors) of ceramic phases, either in the form of particles or as surface coatings, has clearly demonstrated its effectiveness in creating a physical barrier that limits the degradation of the polymer when subjected to the application of a flame or an irradiative heat flux. It also lowers the heat and mass transfer from the degrading polymer to the surroundings and vice versa, hence providing an overall enhancement of heat and fire resistance. This review work seeks to provide an up-to-date overview of the most recent advances in the use of sol-gel methods for conferring flame retardant features to bulk polymers, cellulosic textiles (cotton), and polymer foams. In addition, the current limitations and the potential progresses of these approaches are discussed.

show abstract

Solids containing Si-O-P bonds: is the hydrolytic sol-gel route a suitable synthesis strategy?

Imparato,

Bifulco,

Malucelli

et al. 2023

J Sol-Gel Sci Technol

View full text Add to dashboard Cite

Materials based on silicon-phosphorus mixed oxides have traditionally attracted interest in electronics, optics, catalysis, and related fields. The preparation of a solid containing stable Si–O–P linkages is a huge challenge due to their intrinsic instability to hydrolysis in a wet atmosphere. On the other hand, most technological applications of these materials, such as protonic conductive membranes in fuel cells and water-tolerant solid acid catalysts, are related to their interaction with water; consequently, suitable synthesis procedures that positively face this tradeoff are mandatory. Besides the traditional high-temperature techniques, sol-gel synthetic methods represent a viable, low-cost alternative, allowing for the preparation of high-purity materials with a homogeneous distribution of the components at the atomic scale. Si–O–P linkages are easily obtained by nonhydrolytic sol-gel routes, but only in inert and dry atmosphere. Conversely, hydrolytic routes offer opportunities to control the structure of the products in a wide range of processing conditions. The present review aims at providing an overall picture of the research on the sol-gel synthesis of phosphosilicate and related materials and theisr different applications, emphasizing how the interest in these systems is still lively, considering both conventional and emerging applications, such as flame retardance. The incorporation of Si–O–P nanostructures in polymer composites, coatings, and textiles is indeed a promising strategy to improve properties like thermal stability and fire resistance; however, their in-situ synthesis brings about additional difficulties related to the reactivity of the precursors. The perspectives linked with the development of Si–P-based materials are finally outlined. Graphical Abstract

show abstract

Effects of post cure treatment in the glass transformation range on the structure and fire behavior of in situ generated silica/epoxy hybrids

Cited by 23 publications

References 32 publications

Thermal and Fire Behavior of a Bio-Based Epoxy/Silica Hybrid Cured with Methyl Nadic Anhydride

Thermal and Fire Behavior of a Bio-Based Epoxy/Silica Hybrid Cured with Methyl Nadic Anhydride

Flame retarded polymer systems based on the sol-gel approach: recent advances and future perspectives

Solids containing Si-O-P bonds: is the hydrolytic sol-gel route a suitable synthesis strategy?

Contact Info

Product

Resources

About