Organic–Inorganic Hybrid Materials II: Some Additional Contributions to the Topic

Abstract

By following the successful editorial pathway of the recently published former Special Issue dedicated to Organic–Inorganic Hybrid Materials [...]

The Variance of the Polypropylene α Relaxation Temperature in iPP/a-PP-pPBMA/Mica Composites

“…Particularly in our case, a fourth aspect to consider was the phenomena related to this transition (the α transition) of the polymer matrix (iPP). In the fact, this is a transition usually identified between 40 • C and 90 • C [1,[6][7][8][22][23][24] (in our case between 62.08 • C and 84.28 • C). This is associated with rapid short-range diffusive motions sharply dependent on the molecular mass and the chain entanglement density.…”

“…An isotactic polypropylene, iPP ISPLEN 050 (Repsol), (ρ = 0.90 g/cm 3 ; M w = 334,400; M n = 59,500; T g = −13 • C; Tm = 164.7 • C), and phlogopite mica platelets (KMg 3 [Si 3 AlO 10 ](OH) 2 ), Alsibronz ® (BASF) (ρ = 2.85 g/cm 3 ; specific surface BET = 1.5 m 2 /g; and average particle larger size = 79.8 µm), were used as starting materials as received. Mica was used because its dimensional stability, mean size, and particle size distribution do not vary during the processing steps [3][4][5][6]11,12,25].…”

“…The first point is the fact that this polymer (iPP) represents more than 60% of all the plastics materials produced in the world, remaining at the vanguard of thermoplasticbased advanced materials in terms of performance, markets, and research activities [1,2]. The second is to assume that it is the inter-phase between the components that is going to govern the ultimate properties of the material as a whole [3][4][5][6]. Third, the processing operations play a key role in the emerging morphologies, and therefore, in the generated interfacial area responsible for the final performance of the material [3,4].…”

“…Since a study of the effect of the interfacial agent in a thermoplastic-based composite has been performed under the same processing operations, we had two options: to employ a constant amount of interface agent with a varied number of grafts, or to incorporate a different amount of the interfacial agent by keeping the grafting degree constant. The last is the route we followed in the present study [3][4][5][6]10,15,24].…”

“…Additionally, the real and precise mica content in the material must be reported to not identify as interfacial modifications those due merely to changes in the flow-dynamic of the system (and are then hardly traceable). Nevertheless, since the platelets are mainly aligned with the applied force, the percolation point provides a reinforcing effect by facilitating its transmission through the polymer matrix [3][4][5][6]8,11,24].…”