SRT material, composite and method for producing the same
Using an organic compound having a bottle brush structure, a material having softness and resilience and having excellent low-friction performance (SRT material) can be provided. Preferably, the SRT material contains a reinforcing filler, and may contain a lubricating liquid to be gelled.
1. An organic compound having a branched polymer structure in which plural side chains are branched from a linear or crosslinked main chain and the side chains have an effective surface occupancy σ* of 1% or more represented by the following equation (1):
σ
*
=
1
(
L
×
M
n
,
side
chain
M
n
,
monomer
+
r
main
chain
)
×
(
W
side
chain
/
W
main
chain
)
(
M
n
,
side
chain
/
M
n
,
main
chain
)
×
A
side
chain
2
π
L
(
1
)
(1), wherein:
r main chain represents radius of the main chain;
A side chain represents cross-sectional area of the side chain;
M n, monomer , M n, side chain , and M n, main chain each represents molecular weight of the side chains monomer, number-average molecular weight of the side chains, and molecular weight of recurring unit in the main chain, respectively;
W side chain and W main chain each represents weight of the side chains and weight of the main chain, respectively; and
L represents unit length of polymer chain in the branched polymer structure, and
wherein at least one of the following (i) and (ii) is satisfied:
(i) the side chains have a number-average polymerization degree of 5 to 20, and
(ii) the side chains are branched from the main chain in a density of 1 chain or more per 1 nm length of the main chain.
2. A composite of the organic compound according to claim 1 and a reinforcing filler.
3. The composite according to claim 2 , wherein the reinforcing filler is a cellulose nanofiber.
4. The composite according to claim 2 , satisfying at least one of the following (1) and (2):
(1) the main chains of the organic compound bond to each other via a covalent bond, an ionic bond, a hydrogen bond, a hydrophilic-lipophilic interaction or a phase separation structure,
(2) the organic compound and any one or more of fibrous materials, nonporous inorganic materials and substances having a three-dimensional polymer network structure bond to each other via a covalent bond, an ionic bond, a hydrogen bond, a hydrophilic-lipophilic interaction or a phase separation structure.
5. The composite according to claim 2 , wherein the branched polymer structure of the organic compound has an effective surface occupancy of 1% or more.
6. A method for producing a composite of the organic compound according to claim 1 and a reinforcing filler, comprising graft polymerization using a mixture of a polymer having a recurring unit having a polymerization initiator group and a reinforcing filler.
7. The method for producing a composite according to claim 6 , wherein the mixture is one prepared through polymerization of a monomer having a polymerization initiator group and a reinforcing filler.
8. The method for producing a composite according to claim 6 , wherein the reinforcing filler used in the mixture has a fiber network structure and the fiber network structure is maintained after the polymerization.
9. The method for producing a composite according to claim 8 , wherein the reinforcing filler in the mixture is a cellulose nanofiber of a cellulose gel, and a network of the cellulose nanofiber of the cellulose gel is maintained after the polymerization.
10. A composition comprising the organic compound according to claim 1 .
11. The organic compound according to claim 1 , wherein the side chains have a number-average polymerization degree of 5 to 20.
12. The organic compound according to claim 1 , wherein the side chains are branched from the main chain in a density of 1 chain or more per 1 nm length of the main chain.
13. The composition according to claim 10 , further comprising any one or more of fibrous materials, nonporous inorganic materials and substances having a three-dimensional polymer network structure.
14. The composition according to claim 13 , satisfying at least one of the following (1) and (2):
(1) the main chains of the organic compound bond to each other via a covalent bond, an ionic bond, a hydrogen bond, a hydrophilic-lipophilic interaction or a phase separation structure,
(2) the organic compound and the any one or more of fibrous materials, nonporous inorganic materials and substances having a three-dimensional polymer network structure bond to each other via a covalent bond, an ionic bond, a hydrogen bond, a hydrophilic-lipophilic interaction or a phase separation structure.
15. The composition according to claim 10 , wherein the organic compound is present in an amount of 10% by weight or more.
16. The composition according to claim 10 , further comprising a lubricating liquid.
17. The composition according to claim 10 , having an indentation of 100 nm or more and a compressive elasticity modulus of 1 MPa or more.
18. The composition according to claim 10 , having a frictional coefficient (μ) of 0.1 or less.
19. The composition according to claim 10 , which is in the form of a sheet.
20. The composition according to claim 10 , which is for sliding mechanisms.