Effect of the addition of nanoclays on the water absorption and mechanical properties of glass fiber/up resin composites

Abstract

Mechanical performance of composite materials must remain satisfactory during their life in service. However, composite structures such as wind blades are usually exposed to humid and severe environments, and the absorbed water can degrade the fiber–matrix interface decreasing the composite overall performance. Dual scale (nano-micro) composites can be obtained by adding nanoparticles to the polyester resin and reinforcing that nanomaterial with a glass fiber mat. These materials have good potential in the production of composite parts such as wind blades because nanoparticles dispersed in the polymer matrix could lower the water absorption of the composites and improve their performance in humid environments. However, nanosized reinforcing particles have high internal surface and therefore they tend to agglomerate and are difficult to disperse homogeneously in the polymeric matrix. Moreover, the final properties of the nanocomposites are strongly influenced by clay particles’ morphology and dispersion. In this work, the effect of the addition of pristine and organomodified nanoclays on the water absorption and mechanical properties of glass fiber/unsaturated polyester resin composites was studied. Results showed that the chemical treatments were effective in improving clay dispersion, reducing water absorption, and increasing the composites’ performance in humid environments. In addition, this work presents a procedure to use water absorption tests as means of accelerated humidity absorption tests.

Improving the water resistance of epoxy-anhydride matrices by the incorporation of bentonite

“…Short‐time water absorption depends not only on free volume but also on the number of polar groups where water can be bounded. Several authors have attributed this behavior to the intrinsic hydrophilic clay nature and to the voids resulting of the complex polymer clay composite processing . As B and BM are an important source of polar groups, their addition can explain the M∞ increase.…”

Nanoclay and Water Uptake Effects on Mechanical Properties of Unsaturated Polyester

“…Moreover, exposure of polymers to moisture for long periods is seen to degrade their glass transition temperature (T g ) and mechanical properties. The degradation takes place because of water absorption by the resin, which plasticizes the matrix and weakens the bonded area between the matrix and nanosilicate platelets [7][8][9]. Alamri and Low [8] found that the flexural strength and modulus of epoxy-based nanoclay composites decreased due to the water absorption.…”

“…They however reported that the addition of nanofillers enhanced the flexural strength and modulus of nanocomposites compared to wet unfilled epoxy. Rull et al [9] concluded that nanoclay reinforcement particles reduced water absorption of glass fiber/unsaturated polyester resin composites and increased its performance in humid environments.…”

Pengaruh Penambahan Bentonit Termodifikasi Sebagai Pengisi Terhadap Sifat Mekanik Dan Penyerapan Air Komposit Epoksi

“…Faktor ini mempengaruhi meningkatnya penyerapan air pada komposit dengan peningkatan kandungan bentonit [6]. Faktor yang kedua adalah void, void yang terbentuk pada proses penyediaan komposit dapat menyebabkan meningkatnya penyerapan air pada komposit karena void dapat menyebabkan terbentuknya jalur untuk air agar dapat terserap ke dalam komposit [8], hal ini yang menyebabkan penyerapan air pada komposit dengan komposisi pengisi yang lebih besar mengalami peningkatan sifat penyerapan air. Faktor yang ketiga adalah sifat hidrofobik yang didapatkan setelah dilakukan modifikasi kimia pada bentonit dapat menurunkan penyerapan air pada komposit berpengisi clay [18,17].…”