Home                               Tg Calculation of a Polymer

This program uses the group contribution approach according to Dick W. Van Krevelen to calculate the properties of a polymer . Computational Modeling of Polymers Marcel Dekker (Pg 55 to Pg 123).

Enter the moles or fractional moles of the building blocks. Please check if the total number of moles corresponds to the moles entered. The results are for a high molecular weight polymer.

For low molecular polymers or oligomers enter the number average MW of the oligomer. The Tg as a function of MW is calculated according to: J. V. Alemain J. Poly. Sci. Pol. Chem. Ed. 18 (1980) 256. The constant k is characteristic for a given polymer structure. It can be calculated from know viscosity-composition data of similar polymer structures. 

Tgolig=Tg-k/Mn,  Tgolig Tg of oligomer, Tg of polymer, k constant for a polymer structure, Mn Number average MW,

Viscosity of the oligomer is calculated using the WLF equation according to: L. E. Nielsen, Polymer and Rheology, Marcel Dekker 1977, pp 33, 74, 133

log(vist)=A-[t-Tg]*B/(C+[t-Tg])    A (13), B (17.44), C (51.6) are universal constants for many polymers.

log(vist) is log of viscosity (Poise) at temperature t, Tg is glass transition temperature of polymer.

The WLF equation also permits the calculation of the viscosity at different temperatures. 

  Data to be entered Results      


  Aliphatic Abbreviation


27 acetylene    
16 dimethyl    
38 dimethylsilane    
2 ethylene    
3 ipropyl    
1 methylene    
4 tbutyl    
24 unsaturated_cis    
25 unsaturated_methyl_cis    
25a unsaturated_methyl_trans    
24a unsaturated_trans    
35 anthracene    
60 benzophenone    
55 biphenyl    
58 diphenylether    
57 diphenylsulfide    
59 diphenylsulfone    

17 methylenediphenyl    
56 methyl_phenyl    
8 methylphenyl    
30 mphenyl    
34 naphthalene    
29 ophenyl    
7 phenyl    
22 phenylene    
31 pphenyl    
32 pphenyl_dimethyl    
33 pphenyl_diphenyl    
6 cyclohexane    
5 cyclopentane    
23 1,4-cyclohexane    
44 amide    
9 hydroxyl    
12 acrylester    
45 anhydride    
39 carbonate    
43 ester    
36 ether    
28 ketone    
10 methoxy    
18 meth_acrylic_ester    
37 sulfide    
46 sulfone    
11 vinyl_ester    
13 nitrile    
41 urea    
40 urethane    
15 chloride    
20 chloride_fluoride    
21 dichloride    
19 difluoride    
14 fluoride    
26 unsaturated_chloride    
51 benzimidazole    
53 benzobisthiazole    
54 benzodioxazole    
42 pyromellitic_dimide    
47 oxadiazole    
50 phthalimide    
52 benz_bisimidazole    
48 thiadiazole    
49 thiazole    
  Total Moles of Polymer Fractions       
  Molar Mass, repeating monomer  {M}      
  Molar Number Backbone Atoms {Z}    
  Molar Volume (van der Waals), cm3.mol-1 {Vw}    
  Specific gravity, g/cm3 {M}/{V}    
  Glass transition temperature 1000*{Yg}/{M}, K C
  Melt transition temperature 1000*{Ym}/{M}, K C
  Specific heat capacity {Cps}/{M}    
  Specific heat capacity {Cpl}/{M}    
  Cohesive energy density, Ecoh kJ.mol-1    
  Solubility Parameter, calcm-3/2    
  Oligomer Molecular Weight    
  Oligomer K 10000x k can vary from 3x104 to 5x104    
  Oligomer Glass transition temperature 1000*{Yg}/{M}, K C
  Temperature of oligomer, C    
  Oligomer Viscosity, Poise log              If Viscosity log >6.0 polymer is probably a solid    
  Oligomer Viscosity, Poise    
  Oligomer Viscosity, cps    

Automatic recalculation 

Last edited on:

October 20, 2010

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