The Solubility of Hydrocarbon Gases in Glassy Polymers: Fractal Modeling

Table 1

Values of diameters and force constants (𝜀/𝑘) of C₁–C₄ hydrocarbon gases for the calculation of a solubility coefficient in PVTMS.

Hydrocarbon	𝑑, Å [9, 10]	𝑑ef, Å [11]	𝑑ef, Å, from (6)	(𝜀/𝑘), K [11]
CH4	3.3–4.2	3.18±0.14	3.30	154±15.6
C2H6	3.7–5.2	3.69±0.08	4.06	250±22
C3H8	4.1–5.8	4.09±0.08	4.76	305±28
C4H10	4.6–6.9	4.40±0.08	5.66	364±35
C2H4	3.6–5.5	3.57±0.08	3.82	225±15
C3H6	4.1–5.4	3.86±0.13	4.63	294±32
C4H8	4.5–5.2	4.18	5.36	356
C2H2	3.5–5.7	3.38±0.06	3.70	223±23
C3H4 (m)^a	4.0–4.8	3.62±0.07	4.62	321±25
C4H6 (e)^b	4.4–5.0	3.81	5.26	360
C3H4 (a)^c	4.6–4.9	3.64±0.07	5.38	335±14
C4H6 (b)^d	5.0	3.85	5.45	327

am is methylacetylene.
^be is ethylacetylene.
^ca is allene.
^db is butadiene.