Protective Low-Density Polyethylene Residues from Prepreg for the Development of New Nanocomposites with Montmorillonite: Recycling and Characterization

Abstract

A sustainable alternative to the destination of polyethylene (PE) residue from the prepreg package was established. This work intends to develop nanocomposites for packaging containing neat low-density polyethylene (LDPE), a compatibilizer agent (maleic anhydride grafted-LDPE, LDPE-g-MA), recycled LDPE obtained from the protective films of prepreg (rLDPE) and montmorillonite (MMT). The rLDPE, from the prepreg shield, has a primary role during the transport and storage of prepreg, which can be composed of epoxy resin and carbon fiber or glass fiber. However, this rLDPE is withdrawn and discarded, besides, it is estimated that tons of this material are discarded monthly by the company Alltec Materiais Compostos Ltd. (São José dos Campos-SP, Brazil). Due to several factors, including the lack of technology for recycling, the majority of this material is incinerated. In this context, this work presents a technical and ecologically viable alternative for the use of this discarded material. Nanocomposites of LDPE/rLDPE blends and montmorillonite (MMT) with different contents (0.0, 1.0, and 3.0 wt%) and with the addition of compatibilizer agent (LDPE-g-MA) were prepared by extrusion process. Test specimens were obtained by hot pressing in a hydropneumatic press followed by die-cutting. The nanocomposites produced using rLDPE presented good mechanical, thermal, and morphological properties, being the ideal concentration of 1 wt% MMT. Thus, the results obtained confirmed the viability of recycling LDPE from the prepreg package which contributes to the reduction of waste and the use of this material in technological applications.

The use of recycled low‐density polyethylene films from protective prepreg for the development of nanocomposites with bentonite clay

“…Nanocomposites developed from LDPE residues showed good processability, in addition to good thermal and mechanical properties. The results of the samples with rLDPE proved to be very similar to the Results of the preliminary study of Severino et al [11].…”

“…The processing of the samples was carried out using the same parameters of Severino et al 11 Prior to the melt processing, the BNT clay was oven-dried at 60 C for 24 h. The rLDPE/LDPE-g-MA/LDPE/BNT clay nanocomposites with 1 wt% of BNT clay and 5 wt% of LDPEg-MA were prepared by melt blending in a co-rotational double screw extruder from AX Plásticos (model AX16:40DR). The temperature profile was 170/180/ 180/190/190 C from the first section to the die, operating at a screw rotation speed of 120 rpm and feeding of 30 rpm.…”

“…Compatibilizer agent was prepared according to the previous works by Severino et al 11 and Braga et al, 15 using a mixture of neat LDPE (commercial), MA, and BPO by a reactive extrusion process.…”

“…The rLDPE was received in films form (Figure 1(a)), that presents red color, and it had to be milled (Figure 1(b)) for the production of the nanocomposites blends. The methodology used to milling the rLDPE films waste was based on the study of Severino et al 11…”

“…This material is usually discarded or incinerated and can cause great losses to the environment. In the preliminary study by Severino et al, 11 nanocomposites were developed from the blend of protective composite packaging (rLDPE) and commercial virgin LDPE (50/50) with the addition of maleic anhydride grafted LDPE (LDPE-g-MA) as a compatibilizer agent, and different contents (1, 2, and 3 wt%) of montmorillonite (MMT). According to the authors, the results showed the feasibility of recycling 50% rLDPE with 1 wt% of MMT, as it resulted in better mechanical and thermal properties of the nanocomposites, when compared with commercial virgin LDPE.…”