Characterization and Study of Properties in a Polar Solvent of a Functionalized and Quaternized Poly(dimethylsiloxane-co-methyl-hydridosiloxane)

Abstract

Poly(dimethylsiloxane-co-methyl-hydridosiloxane) (PDMSMHS) with a OSi(CH 3 ) 2 /OSi(HCH 3 ) molar ratio of 21:1 was functionalized with dimethylallylamine (DMAA) via catalytic hydrosilylation using Karstedt's catalyst and then quaternized with 1-iodooctane. The functionalized and quaternized co-polysiloxanes (PDMSMHS-1 and PDMSMHS-QAS) were characterized using 1 H, 13 C and 29 Si NMR. The physicochemical properties of the polymeric systems (the differential refractive index increment (dn/dc), the square root of the mean square radius of gyration (< RMS 2 radius > 1/2 ), the average molecular weight (M), and the second virial coefficient (A 2 )) were measured in ethanol using gel permeation chromatography/light scattering (GPC/LS). The low percentage (3-4 %) of amino side groups has an unexpected effect on the co-polymers physicochemical properties because the A 2 experimental value for PDMSMHS-1 and PDMSMHS-QAS (8.87 × 10 −3 and 1.51 × 10 −2 molmLg −2 , respectively) indicates that ethanol is a good solvent.

Study of Polymer-Solvent Interactions of Complex Polysiloxanes Using Dissipative Particle Dynamics

“…In a recent study, the solubility of a PDMS based random copolymer was modified by functionalization with a polar group [6]. This is an important phenomenon that should be addressed to understand how the functionalization changes the solubility and the interactions that take place between the solvent and the polymer.…”

“…Given the unusual behavior presented by these asymmetrical (the asymmetry, in that case, was with respect to the difference in size of the two types of side groups attached to the silicon atoms) short chains of polysiloxanes with a bulky side group (hexyl and hexadecyl), we made a subsequent theoretical study in which we analyzed the behavior of the A2 and the experimental values of the molecular conformations (obtained from the slope of the graph of the radius of gyration against molecular weight) in a good solvent for short chains of poly-n-hexylmethylsiloxane (PMHS) [5]. We also considered a series of copolysiloxanes with a hydrophilic lateral group, exhibiting good solubility in ethanol with no solubility at all in water and poor solubility in toluene for a copolymer which was mostly polydimethylsiloxane (PDMS) [6]. Even PDMS, by itself, exhibits remarkable features when it is studied in solution, like the draining effect [4,8].…”

Functionalization of polyhydromethylsiloxane with nitrogen-containing organic compounds

“…Using cyclohexylamine-functionalized polymers, membranes on porous polyethylene supports were fabricated and applied for pervaporative enrichment of 1,3-propanediol from binary aqueous mixtures. Guerra-Contreras et al [33] and Lei et al [19] hydrosilylated N,N-dimethylallylamine (DMAA), i.e. a tertiary amine, with PHMS-DMS in the presence of Karstedt's catalyst (anhydrous toluene, 90-100 °C) which afforded amine-substituted polysiloxanes.…”

“…Then Lei et al [19] introduced PDMS blocks at both termini of the modified copolymer to obtain PDMS/amine-modified PHMS-DMS/PDMS triblock copolymer. In both studies, the synthesized polysiloxanes with amine groups were converted to the QAS by treatment with 1-iodooctane [33] or benzyl chloride [19]. The prepared salts showed good solubility in polar organic solvents, such as ethanol [33] and high antibacterial activity [19].…”

Polysiloxanes Grafted with Mono(alkenyl)Silsesquioxanes—Particular Concept for Their Connection

“…It may be performed at the stage of polysiloxanes chain formation, i.a., anionic ring-opening polymerization of cyclic siloxanes, or hydrolytic polycondensation of two chloro/alkoxysilanes varying in functional groups [23,[31][32][33]. On the other hand, it may be achieved by modification of functional group present on the existing polysiloxane chain, mostly via catalytic reactions [34][35][36][37][38][39][40][41][42][43][44], to gain co-polymers with precise and tailored properties [45][46][47][48][49][50][51][52][53][54][55]. Silsesquioxanes represent a versatile group of organosilicon species, with distinct and defined structures, but the most popular are cage silsesquioxanes, especially cubic T 8 [56,57].…”