Modified siloxane rubbery composite membranes for C
This disclosure relates to siloxane membrane materials and polymeric membranes containing the siloxane membrane materials. The siloxane membrane materials are crosslinked with silanol polymers having backbones functionalized with bulky or rigid substituents. This disclosure also relates to methods of using the membranes for natural gas liquid recovery, such as removal and recovery of C 3+ hydrocarbons from natural gas.
1 . A polymer material comprising a repeat unit of Formula (I):
wherein:
R 2 is selected from the group consisting of phenyl, —(C 1 -C 6 alkyl), and —(C 1 -C 6 haloalkyl);
R 2 is selected from the group consisting of phenyl, —(C 1 -C 6 alkyl), and —(C 1 -C 6 haloalkyl);
R 3 is selected from the group consisting of phenyl and —(C 6 -C 18 is alkyl);
m is an integer between 0.35 and 0.4;
p is an integer between 0.03 and 0.05;
n is (1−m−p);
x is an integer between 0.03 and 0.05; and
represents —CH 3 or
2 . The polymer material of claim 1 , wherein R 1 is selected from the group consisting of phenyl and —CH 2 CH 2 CF 3 .
3 . The polymer material of claim 1 , wherein R 2 is selected from the group consisting of phenyl and methyl.
4 . The polymer material of claim 1 , wherein R 1 and R 2 are each phenyl.
5 . The polymer material of claim 1 , wherein R 1 is —CH 2 CH 2 CF 3 and R 2 is methyl.
6 . The polymer material of claim 1 , wherein R 1 is -phenyl and R 2 is methyl.
7 . The polymer material of claim 1 , wherein R 3 is —(C 8 -C 10 alkyl).
8 . The polymer material of claim 1 , wherein R 3 is —(C 8 alkyl).
9 . A crosslinked siloxane composite membrane comprising:
a polymer material comprising a repeat unit of Formula (I):
wherein:
R 1 is selected from the group consisting of phenyl, —(C 1 -C 6 alkyl), and —(C 1 -C 6 haloalkyl);
R 2 is selected from the group consisting of phenyl, —(C 1 -C 6 alkyl), and —(C 1 -C 6 haloalkyl);
R 3 is selected from the group consisting of phenyl and —(C 6 -C 18 alkyl);
m is an integer between 0.35 and 0.4;
p is an integer between 0.03 and 0.05;
n is (1−m−p);
x is an integer between 0.03 and 0.05; and
represents —CH 3 or
10 . The crosslinked siloxane composite membrane of claim 9 , wherein R 1 is selected from the group consisting of phenyl and —CH 2 CH 2 CF 3 .
11 . The crosslinked siloxane composite membrane of claim 9 , wherein R 2 is selected from the group consisting of phenyl and methyl.
12 . The crosslinked siloxane composite membrane of claim 9 , wherein R 1 and R 2 are each phenyl.
13 . The crosslinked siloxane composite membrane of claim 9 , wherein R 1 is —CH 2 CH 2 CF 3 and R 2 is methyl.
14 . The crosslinked siloxane composite membrane of claim 9 , wherein R 1 is -phenyl and R 2 is methyl.
15 . The crosslinked siloxane composite membrane of claim 9 , wherein R 3 is —(C 8 -C 10 alkyl).
16 . The crosslinked siloxane composite membrane of claim 9 , wherein R 3 is —(C 8 alkyl).
17 . The crosslinked siloxane composite membrane of claim 9 , wherein the membrane is cast on a polyacrylonitrile (PAN) support.
18 . The crosslinked siloxane composite membrane of claim 9 , wherein the membrane has a crosslinking density of about 5×10 −5 mol/mL to about 15×10 −5 mol/mL.
19 . The crosslinked siloxane composite membrane of claim 9 , wherein the membrane has a C 3 H 8 /CH 4 single gas selectivity (αc 3 H 8 /CH 4 ) of about 7 to about 25 at feed temperature of 20° C. and feed pressure of 1 bar.
20 . The crosslinked siloxane composite membrane of claim 9 , wherein the membrane has a C 4 H 10 /CH 4 single gas selectivity (αc 3 H 8 /CH 4 ) of about 25 to about 100 at feed temperature of 20° C. and feed pressure of 1 bar.
21 . A method of separating C 3+ hydrocarbons from natural gas, comprising:
providing a crosslinked siloxane composite membrane comprising:
a polymer material comprising a repeat unit of Formula (I):
wherein:
R 1 is selected from the group consisting of phenyl, —(C 1 -C 6 alkyl), and —(C 1 -C 6 haloalkyl);
R 2 is selected from the group consisting of phenyl, —(C 1 -C 6 alkyl), and —(C 1 -C 6 haloalkyl);
R 3 is selected from the group consisting of phenyl and —(C 6 -C 18 alkyl);
m is an integer between 0.35 and 0.4;
p is an integer between 0.03 and 0.05;
n is (1−m−p);
x is an integer between 0.03 and 0.05; and
represents —CH 3 or
22 . The method of claim 21 , wherein R 1 is selected from the group consisting of phenyl and —CH 2 CH 2 CF 3 .
23 . The method of claim 21 , wherein R 2 is selected from the group consisting of phenyl and methyl.
24 . The method of claim 21 , wherein R 1 and R 2 are each phenyl.
25 . The method of claim 21 , wherein R 1 is —CH 2 CH 2 CF 3 and R 2 is methyl.
26 . The method of claim 21 , wherein R 1 is -phenyl and R 2 is methyl.
27 . The method of claim 21 , wherein R 3 is —(C 8 -C 10 alkyl).
28 . The method of claim 21 , wherein R 3 is —(C 8 alkyl).
29 . The method of claim 21 , wherein the crosslinked siloxane composite membrane is cast on a polyacrylonitrile (PAN) support.
30 . The method of claim 21 , wherein the crosslinked siloxane composite membrane has a crosslinking density of about 5×10 −5 mol/mL to about 30×10 −5 mol/mL.
31 . The method of claim 21 , wherein the C 3+ hydrocarbons are more permeable through the crosslinked siloxane composite membrane than methane.