# Patent

## Title
Flexible maleimide polymer and method for preparing the same

## Abstract

Disclosed is a flexible maleimide polymer. The flexible maleimide polymer includes a reaction product of reactants (a)-(c). The reactant (a) is maleimide, a compound with a structure represented by Formula (I), a compound with a structure represented by Formula (II), or combinations thereof




    
    
        wherein R1 is —(CH2)10—CO2H, and R2 is H, OH, SO3Na, NO2, CN or CO2H. The reactant (b) is a compound with a structure represented by formula (III)
    
    






    
    
        wherein A is
    
    






R3 is H or methyl group, x is between 1-12, R4 is H or methyl group, and y and z are both between 1-5. The reactant (c) is a compound with a structure represented by formula (IV), or a compound with a structure represented by formula (V)





    
    
        wherein R5 and R6 are independent H or C1-4 alkyl group.

## Background
CROSS REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from the prior Taiwan Patent Application No. 100149463, filed on Dec. 29, 2011, the entire contents of which are incorporated herein by reference.
TECHNICAL FIELD
The disclosure relates to a maleimide polymer, and in particular relates to a flexible maleimide polymer.
BACKGROUND
Due to its high thermal stability, mechanical strength, and resistance to chemical corrosion, maleimide polymer is applied in a variety of electrical devices. A coating made of the conventional maleimide polymer, however, exhibits inferior film extensibility due to the rigid aromatic linking chain of the conventional maleimide polymer. Further, the conventional maleimide polymer has a high dimensional change under high temperature or by water absorption due the poor dimensional stability of the conventional maleimide polymer.
Moreover, in order to improve the ionic electrical conductivity, a polymer with high ionic electrical conductivity has to be used to blend with the conventional maleimide polymer. Therefore, the application of the maleimide polymer is limited.
SUMMARY
One embodiment provides a flexible maleimide polymer which includes a reaction product of reactants (a)-(c). Particularly, the reactant (a) is maleimide, a compound with a structure represented by Formula (I), a compound with a structure represented by Formula (II), or combinations thereof




wherein R1 is —(CH2)10—CO2H, and R2 is H, OH, SO3Na, NO2, CN or CO2H. The reactant (b) is a compound with a structure represented by formula (II)




wherein A is




R3 is H or methyl group, x is between 1-12, R4 is H or methyl group, and y and z are both between 1-5. The reactant (c) is a compound with a structure represented by formula (IV), or a compound with a structure represented by formula (V)





wherein R5 and R6 are independent H or C1-4 alkyl group.
Another embodiment provides a method for preparing the aforementioned flexible maleimide polymer. The method includes reacting the reactant (a) with the reactant (b) in the presence of a reactant (c) undergoing a polymerization to obtain the flexible maleimide polymer.
A detailed description is given in the following embodiments with reference to the accompanying drawings.


DETAILED DESCRIPTION
Below, exemplary embodiments will be described in detail with reference to accompanying drawings so as to be easily realized by a person having ordinary knowledge in the art. The inventive concept may be embodied in various forms without being limited to the exemplary embodiments set forth herein. Descriptions of well-known parts are omitted for clarity, and like reference numerals refer to like elements throughout.
According to embodiments of the disclosure, a flexible maleimide polymer with high dimensional stability, mechanical strength, and water retaining capacity is provided. The flexible maleimide polymer includes a reaction product of reactants (a)-(c). Particularly, the reactant (a) is maleimide (having a structure represented by




a compound with a structure represented by Formula (I), a compound with a structure represented by Formula (II), or combinations thereof





wherein R1 is —(CH2)10—CO2H, and R2 is H, OH, SO3Na, NO2, CN or CO2H. In order to improve the ionic electrical conductivity of the flexible maleimide polymer, the reactant (a) can include a compound represented by




The reactant (b) is a compound with a structure represented by formula (III)





wherein A is




R3 is H or methyl group, x can be between 1-12 and can not be an integer. For example, x can be 3.5, 5.5, 6.1 or 7.5 (an average value measured by evaluating the molecular weight of reactant (b)). R4 is H or methyl group, and y and z are both between 1-5. Due to the flexible linking chain A, the maleimide polymer prepared from the reactant (b) has superior extensibility and elasticity.

The reactant (b) can have long-chain polyethylene oxide (PEO) linking chain, such as




Further, the reactant (b) can have branched polyethylene oxide, such as





(y and z are from 1-5). The reactant (c) is a compound with a structure represented by formula (IV), or a compound with a structure represented by formula (V)





wherein R5 and R6 are independent H or C1-4 alkyl group. For example, the reactant (c) can be a nitrogen-containing heterocyclic compound, such as imidazole




or 2,4-dimethyl-4,5-dihydro-1H-imidazole





According to an embodiment of the disclosure, the reactant (a) can include maleimide




and the molar ratio between the maleimide and the reactant (c) can be from 5:0.05 to 1:1, or from 4:1 to 1:1. The molecular weight of the flexible maleimide polymer is in inverse ratio to the amount of the reactant (c), and the flexible maleimide polymer with high molecular weight is apt to form gel. Further, the reactant (a) can be, or further include, a maleimide with a functional group (such as





in order to modify the flexible maleimide polymer. The reactant (a) can include the compound with the structure represented by Formula (I) (and/or the compound with the structure represented by Formula (II)), and the molar ratio between the compound with the structure represented by Formula (I) (or Formula (II)) and the reactant (c) is from 4:0.05 to 1:1. Moreover, the molar ratio between the reactant (b) and the reactant (c) is from 2:0.05 to 1:1 or from 1:0.25 to 1:1.

In an embodiment of the disclosure, the method for preparing the flexible maleimide polymer includes the following steps. First, the reactants (a)-(c) are dissolved in an organic solvent (such as dimethyl acetamide (DMAC), or N-methylpyrrolidone (NMP), obtaining a mixture. Next, the mixture is heated and stirred to undergo a polymerization at a reaction temperature. After reacting for a period of time (such as 4-10 hrs), a solution including the flexible maleimide polymer is obtained. The reaction temperature can be from 25 to 180° C. For example, the mixture can be reacted at room temperature or below the boiling point of the organic solvent.
Preparation of Flexible Maleimide Polymer
Example 1
5.12 mmole of maleimide




(reactant (a)), 1.28 mmole of





(reactant (b)), 1.28 mmole of





(reactant (c)), and 30 mL of DMAC (serving as a solvent) were added to a reaction bottle, wherein the molar ratio between





was 4:1:1. Next, the mixture was stirred at 100° C. and continuously examined by gel permeation chromatography (GPC) to confirm the presence of reactants (a) and (b). After reacting for 6 hrs, a red transparent solution including a flexible maleimide polymer was obtained.

Example 2
5.12 mmole of maleimide




(reactant (a)), 1.28 mmole of





(reactant (b)), 1.28 mmole of





(reactant (c)), and 30 mL of DMAC (serving as a solvent) were added to a reaction bottle, wherein the molar ratio between





was 4:1:1. Next, the mixture was stirred at 100° C. and continuously examined by gel permeation chromatography (GPC) to confirm the presence of reactants (a) and (b). After reacting for 6 hrs, a wine-red solution including a flexible maleimide polymer was obtained.

Example 3
3.84 mmole of maleimide




(reactant (a)), 1.28 mmole of





(reactant (a)), 1.28 mmole of





(reactant (b)), 1.28 mmole of





(reactant (c)), and 30 mL of DMAC (serving as a solvent) were added to a reaction bottle, wherein the molar ratio between





was 3:1:1:1. Next, the mixture was stirred at 100° C. and continuously examined by gel permeation chromatography (GPC) to confirm the presence of reactants (a) and (b). After reacting for 6 hrs, a dark red solution including a flexible maleimide polymer was obtained.

Example 4
4.32 mmole of maleimide




(reactant (a)), 1.44 mmole of





(reactant (a)), 1.44 mmole of





(reactant (b)), 1.44 mmole of





(reactant (c)), and 30 mL of DMAC (serving as a solvent) were added to a reaction bottle, wherein the molar ratio between





was 3:1:1:1. Next, the mixture was stirred at 100° C. and continuously examined by gel permeation chromatography (GPC) to confirm the presence of reactants (a) and (b). After reacting for 6 hrs, a wine-red solution including a flexible maleimide polymer was obtained.

Example 5
4.32 mmole of maleimide




(reactant (a)), 1.44 mmole of





(reactant (a)), 1.44 mmole of





(reactant (b)), 1.44 mmole of





(reactant (c)), and 30 mL of DMAC (serving as a solvent) were added to a reaction bottle, wherein the molar ratio between





was 3:1:1:1. Next, the mixture was stirred at 100° C. and continuously examined by gel permeation chromatography (GPC) to confirm the presence of reactants (a) and (b). After reacting for 6 hrs, a red transparent solution including a flexible maleimide polymer was obtained.

Example 6
7.17 mmole of maleimide




(reactant (a)), 2.39 mmole of





(reactant (a)), 2.39 mmole of





(reactant (b)), 2.39 mmole of





(reactant (c)), and 30 mL of DMAC (serving as a solvent) were added to a reaction bottle, wherein the molar ratio between





was 3:1:1:1. Next, the mixture was stirred at 100° C. and continuously examined by gel permeation chromatography (GPC) to confirm the presence of reactants (a) and (b). After reacting for 6 hrs, a red transparent solution including a flexible maleimide polymer was obtained.

Example 7
3.60 mmole of maleimide




(reactant (a)), 1.20 mmole of





(reactant (a)), 1.20 mmole of





(reactant (b)), 1.20 mmole of





(reactant (c)), and 30 mL of DMAC (serving as a solvent) were added to a reaction bottle, wherein the molar ratio between





was 3:1:1:1. Next, the mixture was stirred at 100° C. and continuously examined by gel permeation chromatography (GPC) to confirm the presence of reactants (a) and (b). After reacting for 6 hrs, a red transparent solution including a flexible maleimide polymer was obtained.

Example 8
2.52 mmole of maleimide




(reactant (a)), 0.84 mmole of





(reactant (a)), 0.84 mmole of





(reactant (b)), 0.84 mmole of





(reactant (c)), and 30 mL of DMAC (serving as a solvent) were added to a reaction bottle, wherein the molar ratio between





was 3:1:1:1. Next, the mixture was stirred at 100° C. and continuously examined by gel permeation chromatography (GPC) to confirm the presence of reactants (a) and (b). After reacting for 6 hrs, a red transparent solution including a flexible maleimide polymer was obtained.

Example 9
Example 9 was performed as Example 6 except for substitution of 1.2 mmole of




for 2.39 mmole of





Particularly, the molar ratio between





was 3:1:1:0.5.

Example 10
Example 10 was performed as Example 6 except for substitution of 0.6 mmole of




for 2.39 mmole of





Particularly, the molar ratio between





was 3:1:1:0.25.

Example 11
Example 11 was performed as Example 6 except for substitution of 4.78 mmole of




for 7.17 mmole of





and substitution of 4.78 mmole of





for 2.39 mmole of





Particularly, the molar ratio between





was 2:2:1:1.

Example 12
Example 12 was performed as Example 6 except for substitution of 4.78 mmole of




for 7.17 mmole of





substitution of 4.78 mmole of





for 2.39 mmole of





and substitution of 1.2 mmole of





for 2.39 mmole of





Particularly, the molar ratio between





was 2:2:1:0.5.

Example 13
Example 13 was performed as Example 6 except for substitution of 2.39 mmole of




for 7.17 mmole of





Particularly, the molar ratio of





was 1:1:1:1.

Example 14
Example 14 was performed as Example 6 except for substitution of 11.95 mmole of




for 7.17 mmole of





Particularly, the molar ratio between





was 5:1:1:1.

Example 15
Example 15 was performed as Example 6 except for substitution of 11.95 mmole of




for 7.17 mmole of





substitution of 7.17 mmole of





for 2.39 mmole of





substitution of 4.78 mmole of





for 2.39 mmole of





and substitution of 0.12 mmole of





for 2.39 mmole of





Particularly, the molar ratio between





was 5:3:2:0.05.

Example 16
2.58 mmole of maleimide




(reactant (a)), 0.86 mmole of





(reactant (a)), 0.86 mmole of





(reactant (b)), 0.86 mmole of





(reactant (c)), and 30 mL of DMAC (serving as a solvent) were added to a reaction bottle, wherein the molar ratio between





was 3:1:1:1. Next, the mixture was stirred at 100° C. and continuously examined by gel permeation chromatography (GPC) to confirm the presence of reactants (a) and (b). After reacting for 6 hrs, an orange red transparent solution including a flexible maleimide polymer was obtained.

Example 17
2.55 mmole of maleimide




(reactant (a)), 0.85 mmole of





(reactant (a)), 0.85 mmole of





(reactant (b)), 0.85 mmole of





(reactant (c)), and 30 mL of DMAC (serving as a solvent) were added to a reaction bottle, wherein the molar ratio between





was 3:1:1:1. Next, the mixture was stirred at 100° C. and continuously examined by gel permeation chromatography (GPC) to confirm the presence of reactants (a) and (b). After reacting for 6 hrs, a red transparent solution including a flexible maleimide polymer was obtained.

Example 18
2.49 mmole of maleimide




(reactant (a)), 0.83 mmole of





(reactant (a)), 0.83 mmole of





(reactant (b)), 0.83 mmole of





(reactant (c)), and 30 mL of DMAC (serving as a solvent) were added to a reaction bottle, wherein the molar ratio between





was 3:1:1:1. Next, the mixture was stirred at 100° C. and continuously examined by gel permeation chromatography (GPC) to confirm the presence of reactants (a) and (b). After reacting for 6 hrs, a dark red transparent solution including a flexible maleimide polymer was obtained.

Example 19
2.52 mmole of maleimide




(reactant (a)), 0.84 mmole of





(reactant (a)), 0.84 mmole of





(reactant (b)), 0.84 mmole of





(reactant (c)), and 30 mL of DMAC (serving as a solvent) were added to a reaction bottle, wherein the molar ratio between





was 3:1:1:1. Next, the mixture was stirred at 100° C. and continuously examined by gel permeation chromatography (GPC) to confirm the presence of reactants (a) and (b). After reacting for 6 hrs, a wine-red transparent solution including a flexible maleimide polymer was obtained.

Example 20
2.49 mmole of maleimide




(reactant (a)), 0.83 mmole of





(reactant (a)), 0.83 mmole of





(reactant (b)), 0.83 mmole of





(reactant (c)), and 30 mL of DMAC (serving as a solvent) were added to a reaction bottle, wherein the molar ratio between





was 3:1:1:1. Next, the mixture was stirred at 100° C. and continuously examined by gel permeation chromatography (GPC) to confirm the presence of reactants (a) and (b). After reacting for 6 hrs, a wine-red transparent solution including a flexible maleimide polymer was obtained.

Example 21
2.37 mmole of maleimide




(reactant (a)), 0.79 mmole of





(reactant (a)), 0.79 mmole of





(reactant (b)), 0.79 mmole of





(reactant (c)), and 30 mL of DMAC (serving as a solvent) were added to a reaction bottle, wherein the molar ratio between





was 3:1:1:1. Next, the mixture was stirred at 100° C. and continuously examined by gel permeation chromatography (GPC) to confirm the presence of reactants (a) and (b). After reacting for 6 hrs, a wine-red transparent solution including a flexible maleimide polymer was obtained.

The reactants (a)-(c) and the phase of flexible maleimide polymers as disclosed in Examples 1-21 are shown in Table 1.












TABLE 1









Molar







ratio






reactant
between




reactant (a)
reactant (b)
(c)
reactants
phase







Example 1












4:1:1
liquid


 


Example 2












4:1:1
liquid


 


Example 3



 











3:1:1:1
liquid


 


Example 4



 











3:1:1:1
liquid


 


Example 5



 











3:1:1:1
liquid


 


Example 6



 











3:1:1:1
liquid


 


Example 7



 











3:1:1:1
liquid


 


Example 8



 











3:1:1:1
liquid


 


Example 9



 











3:1:1:0.5
liquid


 


Example 10



 











3:1:1:0.25
liquid


 


Example 11



 











2:2:1:1
liquid


 


Example 12



 











2:2:1:0.5
liquid


 


Example 13



 











1:1:1:1
liquid


 


Example 14



 











5:1:1:1
liquid


 


Example 15



 











5:3:2:0.05
gel


 


Example 16



 











3:1:1:1
liquid


 


Example 17



 











3:1:1:1
liquid


 


Example 18



 











3:1:1:1
liquid


 


Example 19



 











3:1:1:1
liquid


 


Example 20



 











3:1:1:1
liquid


 


Example 21



 











3:1:1:1
liquid









Accordingly, since the flexible maleimide polymer of the disclosure is prepared by reacting a N-phenylmaleimide having a specific function group (such as sulfonic group) with bismaleimide having a flexible and water-retaining linking chain, the flexible maleimide polymer exhibits a high mechanical strength, and water retaining capacity.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed methods and materials. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.

## Claims

1. A flexible maleimide polymer, which is a reaction product of a composition consisting of a reactant (a), a reactant (b), and a reactant (c), and an organic solvent, wherein the reactant (a) has a structure represented by



wherein R is H, —(CH2)10—CO2H, or





and R2 is H, OH, SO3Na, NO2, CN or CO2H;
the reactant (b) is a compound with a structure represented by formula (III)




wherein A is





R3 is H or methyl group, x is between 1-12, R4 is H or methyl group, and y and z are both between 1-5; and
the reactant (c) is a compound with a structure represented by formula (IV), or a compound with a structure represented by formula (V)




wherein R5 and R6 are independent H or C1-4 alkyl group, and wherein the molar ratio between the reactant (a) and the reactant (c) is from 16:1 to 1:1, and the molar ratio between the reactant (b) and the reactant (c) is from 4:1 to 1:1.

2. The flexible maleimide polymer as claimed in claim 1, wherein the reactant (a) is a compound with a structure represented by Formula (I) of




or a compound with a structure represented by Formula (II) of




wherein R1 is —(CH2)10—CO2H, and R2 is H, OH, SO3Na, NO2, CN or CO2H.

3. A method for preparing flexible maleimide polymer as claimed in claim 1, comprising:
polymerizing a reactant (a) with a reactant (b) in the presence of a reactant (c) and an organic solvent to obtain the flexible maleimide polymer, wherein the reactant (a) has a structure represented by




wherein R is H, —(CH2)10—CO2H, or





and R2 is H, OH, SO3Na, NO2, CN or CO2H;
the reactant (b) is a compound with a structure represented by formula (III)




wherein A is





R3 is H or methyl group, x is between 1-12, R4 is H or methyl group, and y and z are both between 1-5; and
the reactant (c) is a compound with a structure represented by formula (IV), or a compound with a structure represented by formula (V)




wherein R5 and R6 are independent H or C1-4 alkyl group, and wherein the molar ratio between the reactant (a) and the reactant (c) is from 16:1 to 1:1, and the molar ratio between the reactant (b) and the reactant (c) is from 4:1 to 1:1.

4. The method as claimed in claim 3, wherein the reactant (a) is a compound with a structure represented by Formula (I) of




or a compound with a structure represented by Formula (II) of




or the molar ratio between the compound with the structure represented by Formula (II) and the reactant (c) is from 4:0.05 to 1:1, wherein R1 is —(CH2)10—CO2H, and R2 is H, OH, SO3Na, NO2, CN or CO2H.