One‐Pot Formation of ZnO‐graft‐Poly(d,l‐Lactide) Hybrid Systems via Microwave‐Assisted Polymerization of d,l‐Lactide in the Presence of ZnO Nanoparticles

Abstract

The surface modification of inorganic nanoparticles by polymer grafting is generally required for obtaining well dispersed polymer‐based (bio)nanocomposites, and the in situ polymerization of corresponding monomers is considered to be a versatile approach to this purpose. In this work, the microwave‐assisted ring‐opening polymerization of d,l‐lactide in the presence of zinc oxide (ZnO) nanoparticles affords an original and straightforward method for generating ZnO‐graft‐poly(d,l‐lactide) hybrid systems. The influence of ZnO particle size and concentration on polymerization kinetics and molar masses of free poly(d,l‐lactide) (PLA) chains is analyzed. Several physico‐chemical techniques, including proton nuclear magnetic resonance (1H NMR), Fourier‐transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and thermogravimetric analysis, are used to characterize intermediates and/or reaction products. Taking into account the kinetic and spectroscopic investigation, competitive chemical pathways based on grafting from and grafting onto reactions are proposed for the one‐pot formation of PLA‐grafted ZnO nanoparticles.

Core–sheath nanofibrous membranes based on poly(acrylonitrile‐butadiene‐styrene), polyacrylonitrile, and zinc oxide nanoparticles for photoreduction of Cr(VI) ions in aqueous solutions

“…Regarding the composite coaxial ABS/PAN-ZnO fibers, it was observed that the higher the ZnO content, the lower the contact angle, probably due to the hydroxyl groups on the ZnO particles surface. 49,50 Considering the polarity, ABS/PAN-ZnO nanofibrous materials can be envisioned as suitable membranes for water purification.…”

Performance of Zinc Oxide Nanoparticles as Polymerization Initiating Systems in the Microwave‐Assisted Synthesis of Poly(d,l‐Lactide)/ZnO Nanocomposites

“…The acceleration effect arising from multi-modal microwave irradiation could initially be attributed to the formation of a greater amount of zinc lactate (during the freeze-drying stage) prone to form the initiating species of LA polymerization, as previously reported by several authors. [8,[9][10][11] However, the FTIR spectrum of the freeze-dried reaction mixture for multi-modal microwave irradiation did not evidence the presence of one such zinc compound (Figure 2c), i.e. after freeze-drying the mixture consisted of only D,L-lactide and ZnO nanoparticles.…”

“…Recently, Rodríguez‐Tobías et al . have carried out the microwave‐assisted ROP of D,L ‐lactide in the presence of ZnO micro‐ and nanoparticles.…”

“…Recently, Rodríguez-Tobías et al [8] have carried out the microwave-assisted ROP of D,L-lactide in the presence of ZnO micro-and nanoparticles. The authors demonstrated that the formation of PLA grafts on the ZnO nanoparticle surface occurred through a series of reactions based on grafting from and grafting onto mechanisms.…”

Surface Modification of nTiO2/Ag Hybrid Nanoparticles Using Microwave-Assisted Polymerization in the Presence of Bis(2-hydroxyethyl) Terephthalate

“…Such modified NPs can be easily homogeneously dispersed and distributed in a polymer matrix to produce a functional nanocomposite [15]. Rodríguez-Tobías et al [17] modified the surface of zinc oxide NPs (ZnO NPs) with polylactic acid (PLA), synthesized by microwaves. The authors proposed grafting mechanisms, between ZnO NPs and the PLA, establishing the existence of different reactions that explain the formation of the hybrid system (ZnO-graft-PLA).…”