Page 92 - 《橡塑技术与装备》英文版2026年3期

HINA R&P TECHNOLOGY AND EQUIPMENT

of rubber compound was weighed and placed in a mold, and 7 days. Then take it out and dry it in vacuum until it reaches
vulcanization was performed at 160℃ and 10 MPa to obtain constant weight (ω 3 ). The calculation formula for bound rubber
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KKNFs SiO 2 /EPDM nanocomposites. The corresponding content (BdR) is as follows:
rubber compound formulation and sample numbers are shown ω 3 -ω 2 -ω 1 m f /(m f +m r )
BdR(%)= ×100 （3）
in Table 1. ω 1 m f /(m f +m r )
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Table 1 Formula of KKNFs SiO 2 /EPDM composite Where m f and m r represent the mass of rubber and filler
material in the rubber compound, respectively.
Sample EPDM/phr KKNFs SiO 2 /phr mKNFs SiO 2 /phr The tensile properties of the sample were tested using
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EPDM 100 0 0
5-mKNFs SiO 2 /EPDM 100 0 5 an electronic universal tensile machine of model CMT-4254.
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1-KKNFs SiO 2 /EPDM 100 1 0 The test was conducted in accordance with the GB/T528-2009
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3-KKNFs SiO 2 /EPDM 100 3 0
5-KKNFs SiO 2 /EPDM 100 5 0 standard, and the sample was a dumbbell-shaped test strip. The
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7-KKNFs SiO 2 /EPDM 100 7 0
results were obtained as the average of five tests.
The ablation performance of EPDM-based insulators was
1.3 Analysis and test tested on a test bench manufactured by Xi'an Zhirui Industrial
Infrared absorption spectroscopy was conducted using
System Engineering Co., Ltd. The experiments were conducted
an FTIR-8400S infrared spectrometer, with a testing range under conditions of oxygen-acetylene gas flow rates of 1512
-1
spanning from 4,000 to 700 cm and a testing step size of 4
L/h and 1116 L/h, and the actual heat flux was calculated to
cm .
-1
be 457 W/cm using a calibrated water-cooled heat flux meter.
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The thermal stability of the sample was tested using a
The test samples used had a diameter of 30 mm and a height of
DTG-60 differential thermal analyzer, with a heating rate of
10℃/min. The temperature range was 25~800 ℃. 10 mm, with a distance of 10 mm between the sample surface
and the nozzle tip. The high-speed oxygen-acetylene flame
The swelling behavior of vulcanized rubber was tested
was positioned vertically at the center of the sample, and the
at room temperature using cyclohexane as the solvent. The ablation process lasted for 20 seconds. The main parameters for
sample was weighed before soaking to obtain ma. After
characterizing the ablation resistance of composite materials
soaking, the soaked sample, which was in swelling equilibrium
are the Mass Ablation Rate (MAR) and the Linear Ablation
and had a stable weight, was wiped and weighed to obtain Rate (LAR), defined as follows:
ms. The crosslinking density of the sample and the average
MAR=(m 1 -m 2 )/t （4）
molecular weight between crosslinks can be calculated
LAR=(d 1 -d 2 )/t （5）
according to the following formula:
Where m1 and d1 represent the initial mass and thickness
m a /ρ
ν r = （1） of the sample before testing, m 2 and d 2 represent the mass
(m s -m a )/ρ 1 +m a /ρ
and minimum thickness of the sample after ablation, and t
2 represents the experimental time.
In(1-ν r ) + ν r+ χν r
ν r = 1/3 （2）
ν o ν r The cross-section of the carbon layer of the ablation
Where ve represents the crosslinking density of the sample was observed using a JSM-6380 scanning electron
sample; ν r denotes the swelling volume fraction of the microscope.
specimen; χ stands for the Flory-Huggins interaction parameter
(0.465); ν o signifies the molar volume of cyclohexane; ρ is the 2 Results and discussion
density of EPDM before swelling; and ρ 1 indicates the density 2.1 Characterization and performance testing
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of cyclohexane. of KKNFs SiO 2
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Weigh 0.5 g of rubber compound sample (ω 1 ), wrap it Figure 1 shows the FTIR spectra of KNFs SiO 2 before
with filter paper (ω 2 ), soak it in 300 ml of cyclohexane at room and after modification with KH550. As can be seen from the
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temperature, replace the solvent every 2 days, and soak for figure, the unmodified mKNFs SiO 2 exhibits peaks at 3,300,

·46· Vol.52，No.3