Page 74 - 《橡塑技术与装备》英文版2026年1月

HINA R&P TECHNOLOGY AND EQUIPMENT

2.3 Mechanical properties
As can be seen from Table 3, the addition of modifiers
has increased the surface tension of the MVQ phase, making
it closer to that of the EPDM phase. This has improved the
compatibility between the two, enhanced the interfacial
adhesion, and increased the tensile strength and tear resistance.
The tensile strength of the EPDM/MVQ blend remains
relatively unchanged and is at a similar level. The tear strength
of the blends with EVM, NBR, and KH-550 as modifiers has
been improved. Overall, the mechanical properties of blends
3#, 4#, and 5# are better than those of the unmodified blend.
(Note: M-1 refers to MVQ, M-2 refers to MVQ/ACM, M-3 refers to MVQ/
EVM, M-4 refers to MVQ/NBR, and M-5 refers to MVQ/KH-550) Furthermore, the increase in tensile strength of blend 5# is
Figure 1 Water contact angles of MVQ, modified MVQ, attributed to the enhanced interaction between rubber and filler
and EPDM due to KH-550. The significant decrease in the elongation at

break is due to the condensation of hydroxyl groups generated
by KH-550 with hydroxyl groups on the surface of silica,
forming chemical bonds, and the formation of hydrogen bonds
on the surface of amino silica. This increases the aggregation
of fillers and the number of stress concentration points. In other
words, the changes in the mechanical properties of blend 5#
are caused by a combination of multiple factors.
Table 3 Mechanical properties of EPDM/MVQ blends
serial number 1 # 2 # 3 # 4 # 5 #
Hardness / Shore A 60 59 61 60 59
Tensile strength / MPa 6.2 5.5 6.3 6.4 6.6
Figure 2 Surface tension and interfacial thickness of the Elongation at break /% 457 428 465 422 387
blend 50% modulus at fixed extension / MPa 1.1 1.1 0.9 1.0 1.1
100% modulus at fixed extension / MPa 1.4 1.5 1.3 1.4 1.6
200% modulus at fixed extension / MPa 2.1 2.1 2.0 2.2 2.8
By modifying MVQ, its surface tension is increased, 300% modulus at fixed extension / MPa 3.2 3.2 3.0 3.4 4.4
narrowing the gap with EPDM's surface tension, achieving Permanent set at break /% 17.5 15.8 14.2 13.3 11.7
-1
Tear strength /(kN·m ) 19.9 19.3 22.6 21.2 23.5
similar surface tension, and enhancing the compatibility
between MVQ and EPDM. As shown in Figure 2, the 2.4 Wear resistance
introduction of NBR can significantly increase the surface Figure 3 compares the wear resistance of different
tension of the MVQ phase, enhancing its compatibility with the EPDM/MVQ blends. Generally speaking, the greater the wear
EPDM phase. This leads to an increase in the mutual attraction volume, the worse the wear resistance. As can be seen from
force between the two phases and an increase in the interfacial the figure, blends 2# and 5# have smaller wear volumes and
thickness. Among the five EPDM/MVQ blends, the 4# blend better wear resistance, while blends 1#, 3#, and 4# have larger
exhibits the best compatibility, with the closest surface tension wear volumes and poorer wear resistance. Among them, the
between the two phases, the strongest mutual attraction force, wear resistance of blends modified with ACM and KH-550 is
the strongest interfacial adhesion, the thickest interphase, and better than that of unmodified blends, while the wear resistance
the worst compatibility in the unmodified 1# blend, with the of blends modified with NBR is inferior to that of unmodified
thinnest interphase. blends.

·28· Vol.52，No.1