Microstructure‐properties correlations in dynamically vulcanized nanocomposite thermoplastic elastomers based on PP/EPDM

Abstract

Thermoplastic vulcanized (TPV) nanocomposites were prepared in a laboratory mixer using EPDM, polypropylene of different viscosities, maleic anhydride modified polypropylene, an organo‐clay, and a sulfur‐based curing system. Based on the obtained results from X‐ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), differential scanning calorimeter, and mechanical properties, the microstructure of the prepared nanocomposites was found to be sensitive to the viscosity difference between the two phases and the clay content. X‐ray diffraction and TEM images of the TPV nanocomposites showed that clay was nearly exfoliated and randomly distributed into the polypropylene phase. The SEM photomicrographs of the dynamically vulcanized thermoplastic elastomer samples showed that the rubber particles were dispersed through the polypropylene in form of aggregates and their size increased with the introduction of clay. The nanoscale dimensions of the dispersed clay resulted in a significant improvement of the tensile modulus of the TPV nanocomposite samples, from 20 to 90% depending on clay content and the viscosity ratio of PP/EPDM. In the PP nanocomposites, the clay layers act as nucleating agents, resulting in higher crystallization temperature and reduced degree of crystallinity. Moreover, the oxygen permeability in the TPV nanocomposites was found to be lower than in unfilled but otherwise similar materials. POLYM. ENG. SCI., 47:207–217, 2007. © 2007 Society of Plastics Engineers.

Blends of ground tire rubber devulcanized by microwaves/HDPE - Part B: influence of clay addition

“…The poor adhesion between the phases and the large particle size of the rubber phase facilitate the propagation of cracks and lead to a pronounced decline of the mechanical properties of the blends [13] . In order to improve the properties of blends containing recycled rubbers, some authors devulcanize the rubber phase [3,9,[14][15][16][17][18] , or add functional fillers [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] . Besides, it is well known that dynamic vulcanization notoriously increases the adhesion and interaction between the phases.…”

Development and applications of polyolefin– and rubber–clay nanocomposites

“…After our success, a lot of researchers have started to study in these field and a huge number of research articles have been published. [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] We expect that clay-based nanocomposite technology is grown into the universal method for high-performance materials from structural to functional ones extensively.…”

Preparation of a new polypropylene/clay nanocomposites via in situ polymerization

“…The addition of fillers, such as glass fiber, talc, and calcium carbonate to the thermoplastic polymer matrix at high loading levels improve properties like stiffness, heat distortion temperature, and dimensional stability. However, these fillers also increase the weight of the thermoplastic, rending them less attractive for automotive and aerospace applications [1,2]. On the other hand, similar benefits but without the weight penalty could potentially be obtained by using a much smaller amount of socalled nanoclays [3], owing to the nanoscale dimension of silicate layers, which brings stronger interfacial interactions between the dispersed solids and the polymer matrix [4].…”

“…On the other hand, similar benefits but without the weight penalty could potentially be obtained by using a much smaller amount of socalled nanoclays [3], owing to the nanoscale dimension of silicate layers, which brings stronger interfacial interactions between the dispersed solids and the polymer matrix [4]. Nanocomposites based on polypropylene have been prepared using a traditional melt mixing process and their properties and microstructures have been published [5][6][7][8][9].…”