Organic Membranes for Selectivity Enhancement of Metal Oxide Gas Sensors

Table 1

Selected structural, thermal, and mechanical properties of the homopolymers used in our study. dc refers to the degree of crystallinity, the glass transition temperature is , is the crystallite melting point, is the continuous operating temperature, and WA is water absorption in 24 h based on weight percent, the density , and the thickness of the membrane sheet. Adapted from data sheets of the suppliers Goodfellow (GF) and Reichelt Chemietechnik (RCT) [69, 70].

Polymer	Structure at (21°C)	[°C]	[°C]	[°C]	WA [24 h, m%]	[g/cm^3]	[μm]
LDPE	Partially crystalline; (dc 40–50%)	<−110; −10	105–110	50–90	<0,015	0,92	10; (GF)
HDPE	Partially crystalline; (dc 70–80%)	<−110	130–135	55–120	<0,01	0,95	10; (GF)
PE + graphite	Partially crystalline	—	—	—	—	0,96	80; (RCT)
PP	Partially crystalline; (dc 60–70%)	−15	160–168	100	<0,05	0,9	10; (RCT)
PMP	Partially crystalline; (dc 65%)	−55; 50	236	120	<0,01	0,83	50; (GF)
PC	Amorphous	148	—	125	0,15–0,35	1,2	20; (RCT)
PET	Amorphous or partially crystalline; (dc 30–40%)	98	250–265	115–150	0,1	1,3 (amorphous); 1,4 (crystalline)	13; (GF)
PEN	Amorphous or partially crystalline; (dc ≈ 5%)	122	267	155	0,4	1,36	12; (GF)
PEEK	Amorphous or partially crystalline; (dc ≤ 48%)	143	334	250	0,1–0,3	1,26 (amorphous); 1,32 (crystalline)	12; (GF)
PA6	Partially crystalline; (dc 50–60%)	−8; 28; 55	230	80–100	2,7	1,13	15; (GF)
PI	Amorphous	250–270	—	250	0,2–2,9	1,42	8; (RCT)
PEI	Amorphous	215	—	170–200	0,25	1,27	25; (GF)
PES	Amorphous	230	—	180–220	0,4–1,0	1,37	25; (GF)