Development of nanocomposites based on organically modified montmorillonite and plasticized PVC with improved barrier properties

Abstract

Montmorillonite (MMT) was organically modified with tributyl citrate (TBC). Organoclays (OMMTs) were processed with diisononyl phthalate (DINP)-plasticized polyvinyl chloride (PVC) to form polymer nanocomposites. The produced composite materials showed a contradictory change in properties to that expected of a layered silicate nanocomposite, with a decreased E-modulus and increased gas permeability compared with a material without OMMT. It was experimentally shown that the TBC modifier was extracted from the OMMT and was dispersed in the PVC/DINP matrix, whereupon the OMMT collapsed and formed micrometer-sized agglomerates. Further investigation revealed that TBC has a significant effect on the gas permeability and the E-modulus, even at low additions to a DINP-plasticized PVC. A PVC nanocomposite with the TBC acting as both the OM for MMT and as the primary plasticizer was produced. This material showed a significantly increased E-modulus as well as a decrease in gas permeability, confirming that it is possible to develop a nanocomposite based on plasticized PVC, if both the organo-modification of the MMT and the formulation of the matrix are carefully selected.

Plasticized Poly(vinyl chloride) Modified with Developed Fire Retardant System Based on Nanoclay and L-histidinium Dihydrogen Phosphate-Phosphoric Acid

“…However, it should be emphasized that in the case of all modified PVC-P series, even those with a minor amount of the modifier, an increase in the VST of approximately 10 • C was recorded, which translates into a significant increase in the scope of their applicability. The results achieved in our experiments are comparable to those observed by Petersen et al [28], who reported the effects of organo-modified montmorillonite (OMMT) interactions on the thermal properties of PVC, and noted the most favorable effect in the case of a 5% nanofiller introduced into PVC plasticized by means of a 40 wt% tributyl citrate.…”

“…Moreover, it can also be a valuable tool for supplementing information about structural changes and the miscibility of polymeric compositions [24][25][26]. Referring to previous literature studies, the introduction of insoluble and inert additives to plasticized PVC, including flame retardants and fillers, may induce different tendencies (both increases and decreases) in PVC-P the thermomechanical stability as assessed by the VST criterion [27][28][29]. The results of the VST measurements are presented in Table 2.…”

Stretchable gas barrier films achieved by hydrogen-bond self-assembly of nano-brick multilayers

“…By hybridizing inorganic nanoplatelets (such as hydrotalcite and montmorillonite) with polymers, multilayer organic-inorganic films called "nano-brick" solve the problem of poor gas barrier property of polymers and simultaneously improve the mechanical property. [13][14][15][16][17][18] Layer-by-layer (LBL) assembly is an effective method to prepare gas barrier coatings through nanoscale control of film architecture. [19][20][21][22][23] Electrostatic layer assembly technology is the earliest and most common method for constructing multilayer films.…”

Role of plasticizer and dispersion methods on the properties of poly(vinyl chloride) and clay nanocomposites

“…Nanocomposites of plasticized PVC with clay have attracted the attention of many researchers , who have observed an improvement in mechanical, thermal, and plasticizer migration using organophilic clay and some authors observed a decrease in mechanical properties when natural clay was used . According to different authors , clay addition can reduce the plasticizer migration in the PVC matrix, but this behavior depends on the plasticizer employed.…”

“…The preparation of PVC/clay nanocomposites differs in the literature. Some studies prepared the nanocomposites by melt mixing without clay pre‐dispersion in the plasticizer. However, Peprnicek et al and Rodolfo Jr. prepared the nanocomposites by melt mixing with mechanical pre‐dispersion of clay in the plasticizer using mechanical mixing, observing an improvement in clay dispersion in the PVC matrix.…”