The thermal degradation behaviour of polydimethylsiloxane/montmorillonite nanocomposites

Thermal Degradation Behavior and Product Speciation in Model Poly(dimethylsiloxane) Networks

“…cyclic monomers, where the hexamethylcyclotrisiloxane or 'D 3 ' cyclic monomer is the thermodynamic and therefore most abundant product. Although it is well known that the thermal stability of polysiloxanes is sensitive to the presence of Lewis acids/bases [6] and organo-metallic catalysts [9], the overall degradation pathways of polysiloxanes have been shown to be remarkably resistant to change in the face of additives, filler materials, catalyst residues or other contaminants [10]. A similar finding was recently reported by Chinn et al [11] for a commercial silicone formulation exposed to increasing amounts of ionizing radiation.…”

“…5) corresponding to: (i) air; (ii) methane, propene and CO 2 ; (iii) branched (v) branched siloxane species & (vii); linear silanoate esters. Such species arise from low levels of secondary side reactions of catalyst residues, reactive degradation products and the products of high temperature radical reactions [10]. When the TIC plots were normalized for sample mass it was found that the levels of the D 3 cyclic as a percentage of the total volatiles evolved were consistently similar across the sample matrix, as shown in Fig.…”

“…The secondary degradation process(es) ('B' in Figs. 1, 2, 3) are generally understood to involve high temperature radically induced crosslinking and -CH 3 abstraction reactions to form branched species, di-cyclics and small molecules (CH 4 and H 2 ) [6,10]. Despite the general similarities between the TGA data shown in Figs.…”

“…This overall mechanism is well established and well understood [6,12,13], significantly less is known, however, about the effects of additives, fillers and differing network topologies on the relative distributions of higher cyclics ([D 3 ), the quantifiable yield of the D 3 thermodynamic product and on the formation of minor products such as methane and carbon monoxide. Indeed, recent work by the authors have shown that PDMS elastomers which physically incorporate nano-scale fillers whilst still forming the D 3 cyclic as the major product of degradation, have a significantly altered profile of minor degradation products [10].…”

The potential of kaolin as a reinforcing filler for rubber composites with new sulfur cure systems

“…12 Bifunctional organosilanes, known also as coupling agent, remedy the problems aforementioned and are used to enhance the reinforcing capability of silicas in rubber. 12 Other fillers such as layer silicates [13][14][15][16][17][18] , carbon nanotubes [19][20][21] , and exfoliated graphene 22,23 have been intensively researched as a potential reinforcing agent in rubber. Several examples of reviews [24][25][26][27] suggest that the nanofillers mentioned above are a promising reinforcing agent to improve mechanical and dynamic properties of rubber particularly at low filler loading.…”