The influence of oxide nanoparticles on the kinetics of free radical methyl methacrylate polymerization in bulk

Abstract

A series of poly(methyl methacrylate) (PMMA) nanocomposites were synthesized using free radical polymerization in bulk, by addition of 1 vol% of oxide nanoparticles (silica, alumina, and titania), differing in the nature and type. The influence of nanofiller presence on the kinetics of methyl methacrylate (MMA) free radical polymerization was investigated. For this purpose, the kinetic model that includes the contribution from the first-order reaction and the autoacceleration was applied on data obtained following the isothermal polymerization at 70 C by differential scanning calorimetry (DSC). The effect of the size and the surface nature of nanofillers on the interfacial layer thickness (d), as well as the influence of d on the glass transition temperature (T g ) of PMMA hybrid materials was studied. It was found that hydrophilic particles accelerated the initiator decomposition and affected the monomer polymerization on the surface, which caused the formation of thicker interfacial layer compared to the one around hydrophobic fillers. The addition of smaller nanoparticles size decreased the glass transition temperature of pure poly(methyl metacrylate). The linear increase of PMMA T g value with increasing the polymeric interfacial layer was determined. The T g values of pure PMMA and PMMA nanocomposite with d of 1.4 nm were estimated to be the same. POLYM. COMPOS., 34:1342COMPOS., 34: -1348COMPOS., 34: , 2013

The novel modeling approach for the study of thermal degradation of PMMA/nanooxide systems

“…1) and its nanocomposites, given in Figure 2c, the glass transition temperatures, Tg, are detected in the temperature interval between 310 and 390 K, which is expected, and it is in accordance with our previous investigation [26]. The glass transition temperatures determined for pure PMMA and the prepared hybrid materials are shifted to lower values by about 5 K when compared with Tg values of the same PMMA systems in reference [26]. This can be explained by the lower sensitivity of the simultaneous TG/DTG and DSC TA Instruments SDT Q600 used in regard to TA Instruments Q20 thermal analyzer.…”

“…The final mixture was put into molds, and the bulk polymerization was performed in an oven at 343 K for 90 min. The polymerization conditions were chosen on the basis of previously reported results concerning the impact of oxide nanoparticles on the kinetics of free radical bulk methyl methacrylate polymerization [26]. The codes of the samples, depending on the nanoparticles type, are given in Table 1.…”

Size effects in 3D‐printed polymer‐derived, zirconium diboride‐reinforced ceramic composites

“…These formulations will be designated as SMP‐10‐ZFA and SMP‐10‐Z, respectively. The FA (Aeroxide Alu C 805, Evonik Industries, Essen, Germany) and ZrB 2 (Grade B, H.C. Stark GmbH, Goslar, Germany) had average particle sizes of 13 nm 22 and 3.6 μm, 5 respectively. The SMP‐10‐Z ink is similar in composition to the ZrB 2 and SMP‐10 formulation described in Kemp et al., 5 with the only difference being that, in the present study, the ZrB 2 was not ball milled.…”

Mechanical and Rheological Properties of Flowable Resin Composites Modified with Low Addition of Hydrophilic and Hydrophobic TiO2 Nanoparticles

“…[28]. In some cases, polymer nanocomposites show an increase of the Tg, but in other cases, a decrease in Tg is observed [30][31][32][33]. In specimens 0.05-I, 0.2-I and 1-I, the hydrophilic TiO2 nanoparticles have a repulsive/dewetting interaction with the surrounding polymer, leading to an increase in free volume and chain mobility near the particles.…”