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BR-102024018272-A2 - Nanocomposite comprising a polyester resin reinforced with natural fibers functionalized with graphene nanoplatelets (NPG); process for obtaining and use in multilayer ballistic armor.

BR102024018272A2BR 102024018272 A2BR102024018272 A2BR 102024018272A2BR-102024018272-A2

Abstract

The present invention applies to the fields of armor materials and discloses a nanocomposite formed by a resin functionalized with graphene nanoplatelets (NPG) and reinforced with natural fibers, its production and use. Multilayer ballistic armor consists of protective compositions formed by several layers of materials for absorbing and dissipating the energy of projectile impacts. However, the addition of layers increases the weight of the armor and limits the user's mobility. Therefore, the present invention offers a solution: an environmentally friendly, low-cost nanocomposite that aims to be an alternative to current market products.

Inventors

  • SERGIO NEVES MONTEIRO
  • ARTUR CAMPOSO PEREIRA
  • LUCIO FABIO CASSIANO NASCIMENTO
  • ULISSES OLIVEIRA COSTA
  • FABIO DA COSTA GARCIA FILHO
  • MICHELLE SOUZA OLIVEIRA
  • MATHEUS PEREIRA RIBEIRO

Assignees

  • INSTITUTO MILITAR DE ENGENHARIA

Dates

Publication Date
20260317
Application Date
20240905

Claims (10)

  1. 1. Nanocomposite CHARACTERIZED by comprising a polyester resin (1) functionalized with graphene nanoplatelets (NPG) (3) and reinforced with natural fibers (2).
  2. 2. Nanocomposite, according to claim 1, CHARACTERIZED by comprising up to 40% natural fiber (2) functionalized with up to 2% NPG (3) in a polyester matrix (1).
  3. 3. Nanocomposite, according to claim 1 or 2, CHARACTERIZED by the fact that the polyester resin (1) is saturated, liquid, isophthalic hardened with 1% methyl ethyl ketone.
  4. 4. Nanocomposite, according to claim 1 or 2, CHARACTERIZED in that the graphene nanoplatelet (NPG) (3) comprises nanometer thickness less than 100 nm.
  5. 5. Nanocomposite, according to claim 1 or 2, CHARACTERIZED by the fact that natural fibers (2) are structured in such a way that they are continuous and aligned and are selected from at least one of the group comprising: piaçava, jute, fique, carnauba and hemp.
  6. 6. Process for obtaining a nanocomposite comprising a polyester resin (1) functionalized with graphene nanoplatelet (NPG) (3) and reinforced with natural fibers (2) CHARACTERIZED by comprising the steps of: (a) Functionalizing the natural fibers (2) with NPG (3); (b) Aligning the functionalized natural fibers (2) together with liquid polyester resin (1); (c) Curing the resin (1).
  7. 7. Process according to claim 6, CHARACTERIZED by the fact that in step (a) the natural fibers (2) are functionalized with up to 2% by weight of NPG (3), in which liquid phase exfoliation occurs.
  8. 8. Process according to claim 6, CHARACTERIZED in that in step (b) the functionalized natural fibers (2) are aligned with the liquid polyester resin (1) in a mold.
  9. 9. Process according to claim 6, CHARACTERIZED in that in step (c), the curing of the resin (1) results from placing it in the mold in a press, preferably of 5 tons, for at least 24 hours.
  10. 10. Use of a nanocomposite characterized by being used in multilayer ballistic shielding, as a second layer after the alumina-based ceramic front layer.

Description

FIELD OF APPLICATION [0001] The present invention applies to the fields of shielding materials. The present invention discloses a nanocomposite material formed by a polyester resin reinforced with natural fibers functionalized with graphene nanoplatelets (NPG), its production and use. FUNDAMENTALS OF THE INVENTION [0002] Multilayer ballistic armor consists of protective compositions made up of multiple layers of materials with specific properties. The layers play a crucial role in absorbing and dissipating the energy from a projectile impact. These layers can include materials such as aramid fibers, ceramics, metal alloys, and special polymers. For example, armed forces worldwide use aramid fiber fabrics commercially known as Kevlar®. The combination of these materials allows multilayer ballistic armor to offer efficient protection against high-powered gunfire, distributing and dissipating the impact energy across the different layers, thus reducing the risk of penetration of the human body. [0003] However, the development and implementation of multi-layered ballistic armor also presents significant challenges. One of the main problems is finding a balance between the strength of the layers and the final weight. Adding multiple layers of materials can significantly increase the weight of the armor, making it less practical and limiting the user's mobility. Furthermore, obtaining materials that are efficient, durable, and low-cost is another obstacle to overcome. [0004] In order to solve the problems described above, the present invention reveals the application of alternative materials that are both affordable and strong enough to withstand high-powered fire. The invention notably provides the advantage of making multilayer ballistic armor more environmentally friendly, economically viable, and widely used. STATE OF THE ART [0005] Document EP1660405 discloses methods for functionalizing carbon nanotubes (CNTs) with organosilanes, where such functionalization allows the fabrication of advanced polymer composites. It is further described that by functionalizing with CNTs in the manner taught in the document, two benefits are obtained. Firstly, the functionalized nanotubes can provide strong bonding to both the fiber (or other CNTs) and the matrix (polymer) through chemical bonding. Secondly, a high level of nanotube unwinding and the formation of relatively soluble materials in common organic solvents can be achieved, thus offering the opportunity for homogeneous dispersion in polymer matrices. In this way, the document discloses polymer composites with CNTs, which in turn are constituted by carbon atoms formed from a graphite sheet (graphene). [0006] However, the information disclosed in this document differs from the present invention in that it does not consider a nanocomposite material formed by a polyester resin functionalized with graphene nanoplatelets (NPG) and reinforced with fibers of piassava, jute, fique, carnauba or hemp. [0007] The article “Piassava Fiber as an Epoxy Matrix Composite Reinforcement for Ballistic Armor Applications” by Fabio da Costa Garcia Filho and Sergio Neves Monteiro (https://doi.org/10.1007/s11837-018-3148-x) describes the ballistic performance of epoxy matrix composites reinforced with piassava fiber, evaluated as an intermediate layer in multilayer armor systems (MAS). The composites were produced by varying the volume fractions of piassava fibers, in the range of 10-50 vol.%, embedded in DGEBA/TETA as an epoxy matrix. These composites were bonded to a multilayer armor system (SBM) composed of a frontal Al2O3 ceramic plate and an aluminum foil alloy as a third layer. Ballistic tests were performed with high-velocity 7.62 mm ammunition. Ballistic results showed that the multilayered armor system using piassava fiber composites as a second layer is within the standard penetration depth limit to be considered effective protection. [0008] Unlike the present invention, the above document describes the manufacture of composites, both reinforced with natural or synthetic fibers, seeking maximum performance with the most suitable reinforcement/matrix interfacial adhesion possible. A negative example would be the case of the pullout effect, which is the tearing of the fiber from the matrix. To overcome this problem, the present invention uses graphene nanoplatelets (GNPs) to improve this interface, considerably improving the shielding product. [0009] The article “Effect of Graphene Oxide Coating on Natural Fiber Composite for Multilayered Ballistic Armor” by Ulisses Oliveira Costa, Lucio Fabio Cassiano Nascimento, Julianna Magalhães Garcia, Sergio Neves Monteiro, Fernanda Santos da Luz, Wagner Anacleto Pinheiro, and Fabio da Costa Garcia Filho (https://doi.org/10.3390/polym11081356) describes composites with natural fibers, specifically a fiber extracted from the leaves of the Amazonian plant curauá (Ananas erectifolius), which is a strong candidate to replace synthetic fibers, suc