HSP Application note #63
Nitrile Butadiene Rubber (NBR) and Hansen Solubility Parameters (HSP)2010.11.28
HSPiP Team Senior Developer, Dr. Hiroshi Yamamoto
Nitrile Butadiene Rubber (NBR) is a family of unsaturated copolymers of AcetoNitrile and various butadiene monomers. Its physical and chemical properties vary depending on the polymer’s composition of nitrile. NBR is generally resistant to oil, fuel, and other chemicals, so it is used in the automotive and aeronautical industry to make fuel and oil handling hoses, seals, and grommets.
2011.4.16
If Radical polymerization is done, image of polymer become like below. Please change composition and push calc. button.
If you want to know much about Radical polymerization, please refer to Pirika polymer
NBR Hansen Solubility Parameters were determined and listed in HSPiP database.
HSPiP(Hansen Solubility Parameters in Practice)The first edition of HSPiP that appeared in November, 2008, greatly enhanced the usefulness of the Hansen solubility parameters (HSP). The HSP values of over 1200++ chemicals and 500 polymers are provided in convenient electronic format and have been revised and updated using the latest data sources in the second edition (March, 2009). A third edition of the HSPiP appeared in March, 2010. There are now 10,000 compounds in the HSP file which also includes data on density, melting point, boiling point, critical parameters, Antoine constants and much more. The user is able to carry out many different sorts of optimisations of solubility, evaporation, diffusion, adhesion, create their own datasets (automatically if required) and explore the huge range of applications for HSP in coatings, paints, nanoparticles, cosmetics, pharma, organic photovoltaics and much more. The 3rd Edition v3.1 was released on 12 December 2010. Current users can upgrade free (now v3.1.09) by downloading the latest .msi installer from http://hansen-solubility.com The 4th Edition v4.0.x was released on 2 Jan. 2013. The Current users can upgrade with free charge. 2013.1.28 The Visual How to manual of HSPiP. You can understand what HSPiP can do. |
| No | dD | dP | dH | Radius | |
| 382 | 19.8 | 17.8 | 3.2 | 19 | Chemical Resistance of Elastomers |
| 31 | 18.62 | 8.78 | 4.17 | 9.62 | Hycar 1052(BF goodrich chemical co.) |
The dP value or Radius is vary depending on the polymer’s composition of Nitrile, or depending on measurement of HSP. We recommend [18.62, 8.78, 4.12] R=9.62.
Hansen SphereTo determine if the parameters of two molecules (usually a solvent and a polymer) are within range a value called interaction radius (R0) is given to the substance being dissolved. This value determines the radius of the sphere in Hansen space and its center is the three Hansen parameters.
From version 3.1.X, Double Spheres function is available. Pirika provide JAVA 3D Demo Applet to browse the Sphere(s). |
This time, I got a lot of swelling data for o-ring materials and re-calculated for NBR.
Hansen Solubility Parameters (HSP)Hansen Solubility Parameters(HSP) were developed by Charles M. Hansen as a way of predicting if one material will dissolve in another and form a solution. They are based on the idea that "like dissolves like" where one molecule is defined as being 'like' another if it bonds to itself in a similar way.
What can perhaps be surprising is that one can assign HSP to so many different things. Gases like carbon dioxide, solids like carbon-60, sugar, and biological materials like human skin, depot fat, DNA, and even some proteins all have HSP. The list can be continued with drugs, polymers, plasticizers, and in fact any organic material and even many inorganic materials like salts. The only requirement for an experimental confirmation is that the material must behave differently in a sufficient number of test solvents upon contact. Pirika JAVA Demo Applet calculate HSP. HSPLight is available here. |
HSP DistanceTo calculate the distance (Ra) between Hansen parameters in Hansen space the following formula is used:
HSP distance(Ra)={4*(dD1-dD2)2 + (dP1-dP2)2 +(dH1-dH2)2 }0.5 |
At first, I prepared the Table.
| Hcode | Name | dD | dP | dH | Vol | Score |
| 552 | 1-pentanol | 15.90 | 5.90 | 13.90 | 108.60 | 0 |
| 1156 | oxalic acid | 17.00 | 17.00 | 26.00 | 61.50 | 0 |
| 1089 | 2,4,6-Trinitrophenol | 19.20 | 7.00 | 12.96 | 130.00 | 0 |
| 92 | butanol | 16.00 | 5.70 | 15.80 | 92.00 | 0 |
| 569 | propyl alcohol | 16.00 | 6.80 | 17.40 | 75.10 | 0 |
| 375 | 2-butoxyethanol | 16.00 | 5.10 | 12.30 | 131.80 | 0 |
| 236 | dichlorodifluoromethane | 14.90 | 2.00 | 0.00 | 81.30 | 0 |
| 7334 | linoleic acid | 16.24 | 3.05 | 5.10 | 311.16 | 0 |
| 3 | acetamide | 17.30 | 18.70 | 17.00 | 59.00 | 0 |
| 5355 | 2-methylheptane | 15.09 | 0.90 | 2.33 | 162.68 | 0 |
| 443 | diisopropyl ether | 15.76 | 3.20 | 3.20 | 135.80 | 0 |
| 326 | monoethanolamine | 16.80 | 6.80 | 20.00 | 60.30 | 0 |
| 368 | ethylene glycol | 17.00 | 11.00 | 26.00 | 55.90 | 0 |
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| 450 | mesityl oxide | 16.40 | 7.20 | 5.00 | 115.20 | 1 |
| 454 | methacrylic acid | 15.80 | 2.80 | 12.00 | 85.30 | 1 |
| 53 | resorcinol | 18.60 | 8.10 | 20.30 | 95.60 | 1 |
| 54 | benzoic acid | 20.00 | 6.90 | 10.80 | 112.40 | 1 |
| 442 | Isopropyl Chloride | 15.00 | 8.00 | 2.00 | 91.70 | 1 |
| 683 | vinyl chloride | 16.00 | 6.50 | 2.40 | 64.70 | 1 |
| 71 | bromobenzene | 19.20 | 5.50 | 4.10 | 105.60 | 1 |
| 334 | bromoethane | 16.50 | 8.40 | 2.30 | 74.60 | 1 |
| 237 | 1,1-dichloroethane | 16.50 | 7.80 | 3.00 | 84.70 | 1 |
○◎(A,B) set Score=0, △X（D,E) set Score=1.
I did not use C rank solvents.
And solvents (Show below) rank is not identical. So I didi not use them.
| 652 | CFC-113 | ×A |
| 650 | trichlorofluoromethane | ×B |
| 219 | dibutyl ether | △ C |
| 169 | m-cresol | △×C |
| 129 | chloroacetic acid | △×C A |
| 603 | octadecanoic acid | ○ D |
| 255 | diethyl ether | ○ E C |
| 615 | tetrachloroethylene | ○△ |
| 234 | o-dichlorobenzene | ○△ C |
| 120 | carbon disulfide | ○△C |
| 618 | 1,2,3,4-tetrahydronaphthalene | ○△D |
| 456 | methyl alcohol | ○C |
| 7032 | maleic acid | ○E |
| 545 | oleic acid | ◎, B, C |
| 325 | ethyl alcohol | ◎,C |
| 930 | 1-hexanol | ◎C |
| 376 | 2-ethoxyethanol | ◎E |
| 305 | dioctyl phthalate | ◎E |
With the total 151 Solvents, I ran the Sphere program and got result of [20.8, 11.3, 3.7] Radius 13.92. The total Wrong In/Out is 21 solvents.
Drag=Rotate, Drag+Shift=Larger/Smaller, Drag+Alt or Command(Window key)=Translate.
If you are using HTML5 enable browser such as Chrome, Safari or FireFox (IE9 is out of support), you will see the Canvas. If you pick solvent, solvent name will appear.
The acid solvents are not good.
The 13 solvents that HSP distance is shorter than sphere radius, even though that will not swell NBR polymer. 10 solvents’ molecular volume is larger than 130. These solvents are dissolve NBR from the point of HSP, but will not dissolve from point of molecular volume.
When the molecular volume become large, it is very complicated, but other case, I can understand these result more than 90% with the concept “likes dissolve likes”.
I summarized the solvents that have more than 130 molecular volume in the table below. All of the distance are shorter than Sphere radius, so from the HSP point of view, NBR will dissolve or swelling. But some of them are rank ◎，◯，B, so we can use NBR for that solvents as packing.
Butyl Stearate or Dioctyl Phthalate are used as Plasticizer.
So these chemicals should dissolve into polymer. And play as plasticizer they should not bleed out from polymer, so molecular volume should larger than free volume of polymer.
| Hcode | name | NBR | Score | Dist | Dist/R | Vol |
| 223 | butyl stearate | ◎ B | 0 | 11.33 | 0.81 | 399.3 |
| 305 | dioctyl phthalate | ◎E | 9.46 | 0.68 | 398.5 | |
| 603 | octadecanoic acid | ○ D | 12.18 | 0.87 | 320.4 | |
| 545 | oleic acid | ◎, B, C | 13.06 | 0.94 | 319.7 | |
| 7334 | linoleic acid | ○B | 0 | 12.38 | 0.89 | 311.2 |
| 7331 | hexadecanoic acid palmitic acid | ◎ | 0 | 12.40 | 0.89 | 290.6 |
| 7740 | 1-pentylnaphthalene | C | 11.07 | 0.80 | 206.1 | |
| 7309 | dicyclohexylamine | C | 11.65 | 0.84 | 198.2 | |
| 528 | glyceryl triacetate | ◎ | 0 | 12.22 | 0.88 | 189.0 |
| 219 | dibutyl ether | △ C | 12.60 | 0.91 | 170.4 | |
| 267 | diethylene glycol monobutyl ether | C | 12.58 | 0.90 | 170.4 | |
| 8064 | alpha-Terpineol | ◎ | 0 | 12.07 | 0.87 | 165.2 |
| 1197 | Dipentene dl-Limonene | ◎○ B | 0 | 11.94 | 0.86 | 162.9 |
| 900 | alpha-pinene | ◎○B | 0 | 12.31 | 0.88 | 159.0 |
| 618 | 1,2,3,4-tetrahydronaphthalene | ○△D | 9.64 | 0.69 | 136.7 | |
| 268 | 2-(2-ethoxyethoxy)ethanol | ◎B | 0 | 12.85 | 0.92 | 136.3 |
| 443 | diisopropyl ether | ◎ | 0 | 12.94 | 0.93 | 135.8 |
| 1089 | Picric Acid (2,4,6-Trinitrophenol) | ○ | 0 | 10.70 | 0.77 | 130.0 |
I selected plasticizers and Flame retardants from table.
All of these chemicals have short distance from NBR polymer, even though the molecular volume is larger than 250.
| Hcode | Name | NBR | Score | Dist | Dist/R | Vol |
| 223 | butyl stearate | ◎ B | 0 | 11.33 | 0.81 | 399.3 |
| 8153 | Decanedioic acid, diethyl ester | × | 1 | 11.70 | 0.84 | 269.4 |
| 16596 | Dioctyl decanedioate | × | 1 | 12.71 | 0.91 | 469.2 |
| 221 | dibutyl phthalate | ×E | 1 | 6.59 | 0.47 | 267.2 |
| 305 | dioctyl phthalate | ◎E | 9.46 | 0.68 | 398.5 | |
| 7334 | linoleic acid | ○B | 0 | 12.38 | 0.89 | 311.2 |
| 7331 | hexadecanoic acid palmitic acid | ◎ | 0 | 12.40 | 0.89 | 290.6 |
| 603 | octadecanoic acid | ○ D | 12.18 | 0.87 | 320.4 | |
| 20645 | Ethanol, 2-butoxy-, phosphate | × | 1 | 10.17 | 0.73 | 398.4 |
| 641 | Tri-n-Butyl Phosphate | ×E | 1 | 10.31 | 0.74 | 274.0 |
| 653 | Tricresyl Phosphate | △×E | 1 | 3.82 | 0.27 | 316.2 |
Some can use for NBR (◎，◯，B) -> blue region.
Some can not use for NBR(X, E) -> red region.
Almost all trend of developing plasticizers or Flame retardants are modify chemicals larger.
But, the Index of Dist/R can suggest other way.
0.80< Dist/R <1.0 with intermediate volume is other choice, I believe.
Data of Seals Eastern, I got swelling data for NBR.
With Gasoline-Alcohol co-solvents, NBR will swelling well, even though individual solvents will not swell.
I calculated Gasoline-Ethanol mixture of HSP and plot the Distance from NBR and Swelling %.
We can easily understand why this co-solvents swell NBR.
(I already explain this phenomena with fluoro containing packing)
Drag=Rotate, Drag+Shift=Larger/Smaller, Drag+Alt or Command(Window key)=Translate.
If you are using HTML5 enable browser such as Chrome, Safari or FireFox (IE9 is out of support), you will see the Canvas. If you pick solvent, solvent name will appear.
HSP of Solvents Mixture[dDm, dPm, dHm]=[(a*dD1+b*dD2), (a*dP1+b*dP2),(a*dH1+b*dH2)]/(a+b)
Volume base ratio. Pirika Java demo applet design solvents mixture. GSD is available here. |
