A Review of Wet Compounding of Cellulose Nanocomposites

Cellulose nanomaterials (CNs) are an emerging class of materials with numerous potential applications, including as additives or reinforcements for thermoplastics. Unfortunately, the preparation of CNs typically results in dilute, aqueous suspensions, and the lack of efficient water removal methods has hindered commercialization. However, water may also present opportunities for improving overall efficiencies if its potential is better understood and if it is better managed through the various stages of CN and composite production. Wet compounding represents one such possible opportunity by leveraging water's ability to aid in CN dispersion, act as a transport medium for metering and feeding of CNs, plasticize some polymers, or potentially facilitate the preparation of CNs during compounding. However, there are also considerable challenges and much investigation remains. Here, we review various wet compounding approaches used in the preparation of cellulose nanocomposites as well as the related concepts of wet feeding and wet extrusion fibrillation of cellulose. We also discuss potential opportunities, remaining challenges, and research and development needs with the ultimate goal of developing a more integrated approach to cellulose nanocomposite preparation and a more sophisticated understanding of water's role in the compounding process.

Influence of different clays on the mechanical, thermal, and water absorption properties of recycled high-density polyethylene/wood flour hybrid composites

Wood plastic composites based on recycled high-density polyethylene (r-HDPE)/wood flour with the addition of organically modified clays were prepared by melt mixing and compression molding. The effect of two different types and contents of clays, bentonite and layered double hydroxide – on the mechanical, thermal, and water absorption properties of the wood plastic composites – was examined to identify the most effective clay type for wood plastic composites. It was found that incorporation of 2 wt% modified bentonite (mBNT) clay was the most effective in the composite formulation; it has significantly enhanced the properties of the wood plastic composites. The scanning electron micrographs of the fractured surfaces showed improved interfacial adhesion of the composite components. The tensile strength of wood plastic composites was increased by 9.7% when 2 wt% mBNT clay was incorporated in the composite formulation; however, the tensile strength slightly decreased as the clay content was further increased. The izod impact strength was lowered about 10.5% by 2 wt% mBNT clay. Moreover, the addition of 2 wt% mBNT clay enhanced the water resistance of the wood plastic composites by 27.5% after immersion in water for five days. On the other hand, the modified layered double hydroxide (mLDH) clay did not cause any remarkable improvement in the properties of the wood plastic composites. The tensile strength showed a decreasing trend with an increase in mLDH content. However, both clays did not improve the thermal stability of wood plastic composites. In addition, there are no noticeable changes in the values of melting temperature by increasing the content of clays. The experimental results indicated that the properties of the wood plastic composites were significantly improved when combined with the appropriate clay type and content. However, the interaction between wood flour and the intercalated clay particles as well as the processing conditions will need further study.

Recent progress on preparation and properties of nanocomposites from recycled polymers: a review

Currently, the growing consumption of polymer products creates the large quantities of waste materials resulting in public concern in the environment and people life. Nanotechnology is assumed the important technology in the current century. Recently, many researchers have tried to develop this new science for polymer recycling. In this article, the application of different nanofillers in the recycled polymers such as PET, PP, HDPE, PVC, etc. and the attributed composites and blends is studied. The morphological, mechanical, rheological and thermal properties of prepared nanocomposites as well as the future challenges are extensively discussed. The present article determines the current status of nanotechnology in the polymer recycling which guide the future studies in this attractive field.

The Influence of EB-Irradiated Treatment on Enhancing Barrier Property and Crystallization Behavior of Rubber-Toughened Nanocomposites

Electron beam (EB) irradiation technique was introduced to modify the crystallization and oxygen (O2) barrier properties of high density-polyethylene (HDPE)/ethylene propylene diene monomer (EPDM) matrix and HDPE/EPDM filled withorganophilic montmorillonite (OMMT). The absorbed dose for EB-irradiation was fixed at 100 kGy. HDPE/EPDM matrix and HDPE/EPDM filled with OMMT at 4 vol% loading were prepared via melt intercalation method. It was found that the barrier resistance of HDPE/EPDM filled withOMMT against oxygen (O2) transmission was significantly enhanced by EB-irradiation absorbed dose of 100 kGy as compared to the control system. The crystallization temperature,Tc, and melting temperature,Tm, were also improved with the addition of OMMT along with the aids of EB-irradiation technique. Field emission scanning electron microscope (FESEM) revealed that the stacking condition of OMMT particles was greatly reduced by EB-irradiation treatment as evidenced by finer surface and less formation of voids.