Reactive blending of poly (dimethylsiloxane) with nylon 6 and poly (styrene):Effect of reactivity on morphology

Abstract

Reactive compatibilization was used to control and stabilize 20-30 wt% poly(dimethylsiloxane) (PDMS) dispersions in nylon 6 (PA6) and poly(styrene) (PS), respectively. The effect of the type of reaction (amine (NH,)/anhydride (An), NH,/ epoxy (E) and carboxylic acid (COOH)/E) on the morphology was studied with electron microscopy. PS and PDMS have mutual solvents and thus it was possible to use gel permeation chromatography (GPC) to determine the concentration of block copolymer in PS/PDMS blends. Reactive blending of PA6 with difunctional PDMS-(An], did not decrease the PDMS particle size compared to the non-reactive blend (-10 pm). Particle size decreased significantly to about 0.5 pm when PA6 was blended with a PDMS containing about 4 random An groups along the chain. For the PS/PDMS blends, GPC revealed that the NH2/An reaction formed about 3940 block copolymer and produced stable PDMS particles -0.4 pm. No reaction was detected for the PS-NH,/PDMS-E blend and the morphology was coarse and unstable. Also, PS-NH,/PDMS-An reactivity was lower compared to other systems such as PS/poly(isoprene) and PS/poly(methylmethauylate) using the same reaction. This was attributed to the relatively thinner PS/PDMS interface due to the high PS/PDMS immiscibility.

EVA reactive blending with Si–H terminated polysiloxane by carbonyl hydrosilylation reaction: From compatibilised blends to crosslinking networks

“…Jorzik and Wolf [16] focused also on the reduction of the interfacial tension between PDMS and polyethylene oxide (PEO) affected by the molecular architecture and chemical composition of the compatibiliser. This was consistent with Macosko et al [7,17], who proved that the copolymer compatibiliser needed to be short enough to diffuse quickly to the interface, but also long enough to prevent coalescence during the mixing of the blend. In the frame of our work, the influence of the different natures of polysiloxane on the final morphology of EVA/ polysiloxane reactive blends was evaluated.…”

“…Furthermore, a few studies have demonstrated the reactive blending of PDMS with organic polymers. Macosko et al [7] worked on the reactive compatibilisation of PDMS with polyamide 6 (PA6) and polystyrene (PS), involving PDMS with modified epoxy or anhydride end-groups. Zhou and Osby [9] also demonstrated the formation of polycarbonate (PC)/ PDMS compatibilised blends through the use of hydroxylterminated PDMS (PDMS-OH).…”

Reactive compatibilization of poly(methyl acrylate‐ran‐acrylonitrile)/poly(ethylene) blends through amine–anhydride coupling

“…η r approaching unity should theoretically result in the minimum domain sizes . Previous studies demonstrated that the amine‐maleic anhydride coupling with similar chain lengths achieved a sub‐micron domain size in other blend systems, even with relatively low η r (η r < 0.05) . Even using completely functional terpolymer, without dilution with non‐functional copolymer, and having η r close to unity, we were not able to achieve sub‐micron dispersions.…”

“…The molecular weights were measured relative to linear PMMA standards. Prior to analysis, polymer samples containing PAS were quenched with phenyl isocyanate to prevent sticking of the amine groups onto the column …”

“…Since a 2D surface of a 3D sample was analyzed by SEM, the calculated diameter does not represent the true size of the domains. Stereological corrections are necessary but previous studies have shown that a relatively small increase of 10–15% in domain sizes is typical and thus were not done here 〈D〉vs was calculated by using eq.…”