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BMI-689 Low Viscosity Liquid Bismaleimide

Harmonization Code : 2925.19.95.90 |   Carboxyimide-function compounds (including saccharin and its salts) and imine-function compounds : Imides and their derivatives; salts thereof : Other : Other : Other
Main features
  • Hydrophobic
  • High adhesion to various substrates
  • Superior thermal stability

Product Description

BMI-689 is a unique low viscosity liquid bismaleimide based on a non-hydrogenated dimer diamine backbone. It can be homo-cured via UV or free radical initiators to form tough, hydrophobic, cross-linked polyimides. The material has excellent low pH hydrolytic resistance and thermal stability. The amorphous nature of this BMI allows it to be used in a variety of applications including mixed cure systems (e.g. epoxy and BMI), mixed BMI systems or where a low viscosity, free radical cured resin is required. It is soluble in most aromatic and aliphatic solvents such as toluene, xylene, NMP, etc.

BMI-689 is recommended for use as an additive or base resin in adhesives that are designed for high temperature resistance. It has excellent adhesion to a variety of substrates. When used as a base resin, it can produce films that are tough, flexible and demonstrate good peel strength. 

Product Family
BMI-689  
1kg Jar
Normal Price
$1,040.829
Sale Price
$800.638/Jar
Quantity OrderedPrice per Jar
  1 - 4 Jar  $800.638 /Jar
  5 - 9 Jar  $620.594 /Jar
  10 - 24 Jar  $500.557 /Jar
  25 - 99 Jar  $440.539 /Jar
  100 - 499 Jar  $380.532 /Jar
$380.53
Shipping in 2 - 4 weeks Shipping in 2 - 4 weeks

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Technical Specifications

General Properties
Appearance
Appearance
Appearance at room temperature.
Yellow to amber liquid
Functionality 2
Molecular weight 689 daltons
Mechanical Properties
Viscosity
Viscosity
Viscosity is a measurement of a fluid’s resistance to flow.

Viscosity is commonly measured in centiPoise (cP). One cP is defined as
the viscosity of water and all other viscosities are derived from this base. MPa is another common unit with a 1:1 conversion to cP.

A product like honey would have a much higher viscosity -around 10,000 cPs-
compared to water. As a result, honey would flow much slower out of a tipped glass than
water would.

The viscosity of a material can be decreased with an increase in temperature in
order to better suit an application
Viscosity @ 25°C 1500 cP
Thermal Properties
Weight Loss
Weight Loss @ 300°C 1.0 %
Decomposition Temperature >400 °C
Other Properties
Storage Temperature 5 °C

Additional Information

The use of DMI BMI-BCI resins with epoxy can add a great deal of flexibility when optimizing a resin system to meet specific needs.

  • The BMI-BCI/epoxy system can be cured in air for a tack-free surface. 
  • Data shows lower cure temperature than either resin cured alone.
  • Increasing the BMI-BCI content decreases the moisture absorption of the system. 
  • Small quantities of epoxy can significantly increase adhesion of the mixture.

Almost linear adjustability is available for properties such as: 

  • Viscosity
  • Glass Transition Temperature
  • Coefficient of Thermal Expansion
  • Dielectric Properties

Another BMI-BCI/epoxy system feature is that most combinations turn black upon curing without the use of colorants or carbon.

 

The hydrophobic nature of the DMI BMI-BCI resins helps limit the moisture absorption observed after exposure to 168 hours of 85°C/85% RH. Significant reduction in moisture absorption was obtained with samples containing a high fraction of BMI resin. The more BMI in the system the better the resistance against humidity.

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The BMI-689/epoxy system exhibits thermal property changes in a manner similar to that of the viscosity.

The Tg, α1 CTE and modulus can all be controlled by formulation selection.

 

#

EW Epoxy:BMI

Tg (C)

α1 (ppm/C)

Modulus (GPa)

1

1:9

50

161

0.46

2

1:4

60

146

0.65

3

1:3

69

143

0.54

4

1:2

55

150

0.68

5

1:1.5

44

131

0.93

6

1:1

43

119

1.24

7

2:1

58

120

1.30

8

3:1

83

104

1.50

9

6:1

100

85

1.68

10

1:0

119

65

1.75

 

 

DK/Df values of cured BMI/Epoxy mixtures were investigated and plotted below.  The dielectric properties of the system can be controlled by varying the level of BMI to epoxy. 

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Blue= BMI-689/epoxy - Orange= BMI-1500/epoxy

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It is important to point out the improved shear strength that formulations using BMI exhibit. As you can see, the amount of BMI enhances the compression shear strength on PC/PC substrates in the initial phase and on the long run at higher temperatures. As expected there is a drop in strength at medium temperatures since Bismaleimides are generally made to perform better at elevated temperature conditions.

Something interesting to note is that initial strength at Alu/Alu substrate testing is not performing well and drops from 25MPA to 5 MPa with 20% BMI content. It is possible that this will improve in different analogies and given enough time and temperature but this has not been tested.