Contents 1. Selected 1 H and 13 C NMR spectra for poly(ethylene-co-t-butylethylene)s prepared by using Cp′TiCl 2 (O-2,6-i Pr 2 C 6 H 3 ) [Cp′ = Cp* (1), t BuC 5 H 4 (2), 1,2,4-Me 3 C 5 H 2 (6)]-MAO catalyst systems. 2. Selected GPC profiles for poly(ethylene-co-t-butylethylene)s prepared by using Cp′TiCl 2 (O-2,6-i Pr 2 C 6 H 3 ) [Cp′ = Cp* (1), t BuC 5 H 4 (2), 1,2,4-Me 3 C 5 H 2 (6)]-MAO catalyst systems. 3. Selected DSC thermograms for poly(ethylene-co-t-butylethylene)s 4. 13 C NMR spectra for poly(1-hexene), poly(1-hexene-co-vinyltrimethylsilane), and poly(vinyltrimethylsilane) prepared by using ( t BuC 5 H 4 )TiCl 2 (O-2,6-i Pr 2 C 6 H 3 ) (2) and CpTiCl 2 (N=C t Bu 2 ) (3)-MAO catalyst systems.
Silyl ethers of ethyl cellulose (2a-f) were synthesized in good yields by the reaction of various chlorosilanes with residual hydroxy groups of ethyl cellulose. 1 H NMR and FTIR spectra of the silylated polymers furnished the evidence for complete substitution of hydroxy protons by the silyl groups. Silylated derivatives of ethyl cellulose (2a-f) were soluble in common organic solvents and displayed enhanced solubility in relatively nonpolar solvents due to the substitution of hydroxy groups. The onset temperatures of weight loss of the silylated derivatives (2a-f) in air were higher than 270 °C, indicating fair thermal stability. Free-standing membranes of 1 and 2a-f were fabricated by casting their toluene solution, and all the silylated derivatives (2a-f) exhibited enhanced gas permeability (P) as compared to that of ethyl cellulose ( 1). An increment in the size of the silyl group led to the decrement in gas permeability of the polymers, and trimethylsilyl derivative (2a) exhibited the highest P value. The P CO2 /P N2 permselectivity values of the polymers (2a-f) were observed to be in the range of 15-19. The data for 2a, 2b, and 2c were located above Robeson's upper bound, in the plot of permselectivity vs permeability for the CO 2 /N 2 gas pair (P CO2 vs P CO2 /P N2 ). Gas diffusion coefficients (D) increased upon silylation for all the six gases under study, while gas solubility coefficients (S) underwent a decline.
First and second generation amidoimide dendrons (G1-a-II−G1-c-II and G2-a-II−G2-c-II) having
branched alkyl periphery and focal carboxyl functionality were synthesized via a convergent pathway and
incorporated into ethyl cellulose. Dendronized ethyl cellulose derivatives (2a−c, 3a−c) were synthesized in good
yield by the reaction of the terminal carboxyl moiety of various dendrons with residual hydroxy groups of ethyl
cellulose (1; degree of substitution with ethyl group (DS
Et), 2.69). 1H NMR spectra and elemental analysis were
employed to determine the degree of esterification (DS
Est) of the resulting polymers. The presence of the peak
characteristic of the CO group in the FTIR spectra accomplished further evidence for the incorporation of
dendritic moieties into ethyl cellulose. All of the derivatives (2a−c, 3a−c) were soluble in chloroform and methanol,
and the solubility window narrowed in going from G1- to G2-derivatized polymers. The onset temperatures of
weight loss of 2a−c (295−325 °C) and 3a−c (312−320 °C) in air were slightly higher than 294 °C, indicating
that the thermal stability was retained upon dendron functionalization. Free-standing membranes of 1 and 2a−c
were fabricated, and 2a−c exhibited enhanced permselectivity for He/N2, H2/N2, CO2/N2, and CO2/CH4 gas pairs
as compared to 1.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.