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Full text of "USPTO Patents Application 10687092"

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WHAT IS CLAIMED 



1) 



2) 



3) 



4) 



A process for the preparation of polymer-grafted 
natural fibers comprising the following steps: 
converting the hydroxyl groups on the natural 

fiber into the corresponding salified alcoholate 

groups ; 

grafting on the salified alcoholate groups a 
functionalized polyether containing a leaving 
group that favors nucleophilic substitution. 

The process according to claim 1. "herein the 
step of converting the hydroxyl groups is 
preceded by a step of pre-treating the natural 
fibers by drying. 

The process according to claim 2, wherein the 
step of pre-treating the fibers is carried out 
und er vacuum at a temperature in the range of 
•from 50«C to 100-C for a time of between 2 and 48 
hours . 

The process according to claim 1. wherein the 
step of converting the hydroxyl groups into 
salified alcoholate groups is done by adding the 



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5) 



6) 



7) 



8) 



pre-treated fiber to an anhydrous reagent 
solution in an inert atmosphere. 

The process according to claim 4, wherein the 
anhydrous reagent solution comprises an alkaline 
reagent . 

The process according to claim 5, wherein the 
reagent is potassium tert-butylate and 18-crown-6 
ether in anhydrous tetrahydrof uran. 

The process according to claim 5, wherein the 
reagent is sodium methylate in anhydrous methyl 
alcohol . 

The process according to any of the foregoing 
claims, wherein the f nationalized polyether has 
the general formula (I) 

R[-0-X-] m Y (i) 

1 

where : j 

! m is between 1 and 200; 

r is an aliphatic or aliphatic/aromatic group; 
Y is a functional leaving group; 



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9) 



X = 



Ri 

I 

-C 
I 

R 2 



Jn 






where 

n is between 1 and 20; 

Rl is the same as or different from R2 and is 
either hydrogen or a linear or branched aliphatic 
group ; 
or 



X = 



having at the positions of the ring a) , b) , c) 
and d) one or more substituting groups which may 
be the same or different from each other and 
which may be a group comprising a halogen or a 
linear or branched C1-C4 alkyl . 

The process according to claim 8, wherein the 
functional! zed polyether of the general formula 
(I) is: 

R[-0-X-] m Y (i. 

where : 

m is between 4 and 60; 



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R is hydrogen, a linear or branched C1-C4 alkyl 
group, or a benzyl group; 
Y is iodine or mesyl ; 

Ri 



X = 



-C- 
i 

R 2 






Jn 

where 

n is between 2 and 5; 

Rl is the same as or different from R2 and is 
either hydrogen or a linear or branched alkyl 
group ; 
or 



X = 



having at the positions of the ring a) , b) , c) 
and d) two substituting groups which may be the 
same or different from each other and which may 
.be a group comprising chlorine, bromine and 
iodine or a linear or branched C1-C4 alkyl. 

The process according to claim 8, wherein the 
polyether is polyoxyethylene , polyoxypropylene or 
polyethylene terephthalate . 



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11) 



12) 



The process according to claim 7, wherein the 
step of adding the reagent is followed by one or 
more steps of filtering and washing with 
anhydrous tetrahydrofuran. 

A polymer-grafted natural fiber wherein the 
polymer is a polyether. 



13) The grafted fiber according to claim 12, wherein 
the fiber is a cellulose fiber and the polyether 
graft has the general formula (I) 

R[-o-X-] m id 

where : 

m is between 1 and 2 00; 

r is an aliphatic or aliphatic /aromatic group; 

Ri " 

-c- 



X = 



R> J 



n 



where 

n is between 1 and 20; 

Rl is the same as or different from R2 and is 
either hydrogen or a linear or branched aliphatic 
group ; 



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or 



X = 






having at the positions of the ring a) , b) , c) and 
d) one or more substituting groups which may be 
the same or different from each other and which 
may be a group comprising a halogen or a linear 
or branched C1-C4 alkyl . 

14 ) A polymer-grafted natural fiber obtained using a 
process according to any of the foregoing claims 
from 1 to 11. 



15) 



16) 



A composite material comprising polymer-grafted 
natural fibers, wherein the polymer is a 
polyether . 

The composite material according to claim 15, 
wherein the natural fibers are grafted with a 
polyether of the general formula (I) : 

R[-0-X-] m d> 

where : 

m is between 1 and 200; 

R is an aliphatic or aliphatic/aromatic group; 



30 



X = 



17) 



Ri 

l 

-c- 

I 

R 2 






-in 

where 

n is between 1 and 20; 

ri is the same as or different from R2 and is 
either hydrogen or a linear or branched aliphatic 

group ; 
or 



X = 



having at the positions of the ring a), b) , O 
and d) one or more substituting groups which may 
be the same or different from each other and 
which may be a group comprising a halogen or a 
linear or branched C1-C4 alkyl . 

The composite material using polymer-grafted 
' natural fibers, wherein the natural fibers are 
grafted with polymers using the process according 
to one or more of the foregoing claims from 1 to 
11. 



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Use of polyether-graf ted natural fibers for the 
preparation of composite materials. 

Use of polymer-grafted natural fibers for the 
preparation of composite materials, wherein the 
natural fibers are grafted according to one or 
more of the foregoing claims from 1 to 11. 



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