Transparent Multi-Layer Acrylic Composites Reinforced with poly(Acrylated Urethane) Filled Low Grammage Bacterial Cellulose Nanopaper.

Cellulose nanopaper is a material structure that possess high mechanical performance and is widely regarded as a promising two-dimensional reinforcement for polymer matrix composites. This work explores the use of low grammage bacterial cellulose (BC) nanopaper as reinforcement for poly(acrylated urethane) interlayer adhesive to increase the impact performance of multi-layer acrylic composites. The BC nanopaper is impregnated with an acrylated urethane resin and laminated between acrylic sheets to create BC/acrylic composites consisting of one, three and five layers of BC nanopaper-reinforced poly(acrylated urethane) interlayer adhesive(s). Both the the poly(acrylated urethane)-filled BC nanopaper interlayer adhesive and the resulting laminated acrylic composites are optically transparent. The incorporation of BC nanopaper into the poly(acrylated urethane) interlayer adhesive improves the tensile modulus by eightfold and the single-edge notched fracture toughness by 60% compared to neat poly(acrylated urethane). It was also found that using poly(acrylated urethane)-filled BC nanopaper interlayer adhesive proved beneficial to the impact properties of the resulting laminated acrylic composites. In Charpy impact testing, the impact strength of the multi-layer acrylic composites increased by up to 130% compared to the "gold-standard" impact-modified monolithic acrylic, with a BC loading of only 1.6 wt.-%. This article is protected by copyright. All rights reserved.