The thermal properties required for the design of SUMIKAEXCEL PES are shown in Table 3-1-1.

Table 3-1-1 Thermal Properties of SUMIKAEXCEL PES

Heat resistance	Test method	Unit	Unreinforced	Glass fiber reinforced
			4100G 4800G	3601GL20 4101GL20	3601GL30 4101GL30
Deflection temperature under load (0.45MPa)	ASTM D648	°C	210	-	-
Deflection temperature under load (1.82MPa)	ASTM D648	°C	203	210	216
Deflection temperature under load (0.45MPa)	ISO 75	°C	214	222	223
Deflection temperature under load (1.80MPa)	ISO 75	°C	205	221	221
Vicat softening point (1kg)	ASTM D1525	°C	226	-	-
Vicat softening point (5kg)	ASTM D1525	°C	222	-	-

Arrhenius Plot

The temperature range where the resin can be used for a long period of time is limited by the thermal stability of the resin. According to the UL-compliant relative temperature index (RTI), the aging test continues until the observation target property value becomes half the initial value. Perform aging tests at several different temperatures and create an Arrhenius plot based on that data. An Arrhenius plot is a graph created by plotting the heat aging time (also called half-life) required for the property value to reach half the initial value against the reciprocal of the aging temperature (K).

Long-Term Heat Resistance

SUMIKAEXCEL PES has excellent long-term heat resistance. The following shows the relative temperature index (RTI) for SUMIKAEXCEL PES. The RTI indicates the temperature at which the impact strength (Imp) and tensile strength (Str) of the electrical properties (Elec) and mechanical properties (Mech) become half their initial values after the material is aged 100,000 hours. Generally, deterioration is more rapid for thin test pieces, so RTI evaluation for UL is performed according to the thickness of the test piece.

Table 3-1-2 Relative Temperature Index of SUMIKAEXCEL PES (UL746B)

Grade	Thickness (mm)	RTI
		Elec	Imp	Str
3600G	0.41	-	-	-
	0.75	180	170	180
	1.6	180	170	180
	3.0	180	170	180
4100G	0.41	180	170	180
	0.75	180	170	180
	1.5	180	170	180
	3.0	180	170	180
4800G	0.30	180	170	180
	0.46	180	170	180
	1.5	180	170	180
	3.0	180	170	180
3601GL20	0.43	180	180	180
	3.0	180	180	180
3601GL30	0.43	190	190	190
	3.0	190	190	190
4101GL20	0.43	180	180	180
	1.5	180	180	180
	3.0	180	180	180
4101GL30	0.43	190	190	190
	1.5	190	190	190
	3.0	190	190	190

Temperature Dependence of Flexural Modulus

Figure 3-1-3 shows the temperature dependence of flexural modulus. The flexural modulus shows almost no change from 100 to 200°C. It is far superior to noncrystalline polycarbonate resins and glass fiber reinforced grades of crystalline PPS resins, especially above 100°C, and belongs to the highest class of thermoplastic resins.

Figure 3-1-3 Temperature Dependence of Flexural Modulus of 4100G and 4101GL30

Aging Characteristics (in Air and in Hot Water)

Heat Aging Resistance

PES has excellent heat aging resistance property. Even after aged in air at 150°C, the strength remains stable.

Figure 3-1-4 Heat Aging Resistance of Tensile Strength, in Air at 150°C

Hot Water Resistance

When SUMIKAEXCEL PES is immersed in water (23°C) or hot water (100°C) without loading, there is almost no change in tensile strength. The impact strength of SUMIKAEXCEL PES will initially decrease when exposed to hot water (100°C), but will thereafter remain stable, maintaining a sufficiently high level of impact resistance.

Figure 3-1-5 Hot Water Resistance of Tensile Strength

Figure 3-1-6 Hot Water Resistance of Impact Strength

Steam Resistance (Steam Sterilization Resistance)

No changes to impact strength were observed as a result of cyclical tests using a steam pressure of 3.2 atmospheres (143°C) vacuum dehydration (room temperature).
However, when PES is to be used in steam, testing should be performed prior to usage at actual operating temperatures, in accordance with the specified application.