Page 91 - 《橡塑技术与装备》英文版2026年3期

TEST AND ANALYSIS

strength (9250~11100 MPa), high modulus (over 200 GPa), orthosilicate (TEOS), and epichlorohydrin (ECH) were all
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and low density (1.57 g/cm ). By undergoing deprotonation, provided by Sinopharm Chemical Reagent Co., Ltd.
Kevlar fibers can be nano-dispersed into Kevlar nanofibers 1.2 Preparation method
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(KNFs), combining the advantages of Kevlar fibers, such as Preparation of KKNFs SiO 2 : Weigh 5g of Kevlar49
high strength, high modulus, and low density, with the nano- yarn and cut it into 1~2 cm segments. Soak the segments in
effects of high-performance polymer nanofibers, including anhydrous ethanol and subject them to ultrasonic treatment
high specific surface area and high aspect ratio. After further for 6 hours. After washing with deionized water and drying
modification, the interfacial interaction between KNFs and thoroughly, mix them with 5g of potassium tert-butoxide in a
EPDM can be significantly enhanced. Wang et al. prepared round-bottom flask containing DMSO and stir for 10 minutes.
modified KNFs with good water dispersibility by grafting Then, add 5g of anhydrous methanol and stir for 6 hours to
epoxy groups onto KNFs, and then prepared modified KNFs/ obtain a DMSO dispersion of KNFs. React this dispersion
XNBR nanocomposites. The results showed that after adding with 2mL of epichlorohydrin at 30℃ for 24 hours to obtain
5 parts of modified KNFs, the tensile strength of the XNBR modified Kevlar nanofibers (mKNFs), and wash them until
nanocomposites increased by 182.0%, the tear strength neutral at 12,000 rpm. Subsequently, react them with KH550
increased by 101.0%, and the mechanical properties were for 5 hours, and then add 10mL of TEOS and react for 3 hours
significantly improved. to obtain Kevlar nanofibers with in-situ grown nano-silica on
In this paper, EPDM served as the matrix, and nano- the surface (mKNFs SiO 2 ). Disperse the mKNFs SiO 2 aqueous
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silica was grown in situ on the surface of KNFs. Subsequently, dispersion in deionized water to obtain a dispersion with a
γ-aminopropyl triethoxysilane (KH550) was grafted onto concentration of 2.5 mg/mL. Add 0.02 mol of KH550 to the
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the KNFs through condensation polymerization, resulting mKNFs SiO 2 aqueous dispersion and stir at 60℃ for 2 hours
in γ-aminopropyl triethoxysilane (KH550) modified KNFs @ to obtain KKNFs SiO 2 . Vacuum filter the unreacted KH550
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SiO 2 (KKNFs SiO 2 ). The influence of the amount of KKNFs @ and wash it with an ethanol aqueous solution until neutral.
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SiO 2 on the mechanical properties, crosslinking density, Finally, disperse KKNFs SiO 2 in deionized water to obtain a
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thermal stability, and ablation performance of KKNFs SiO 2 / dispersion with a concentration of 2.5 mg/mL and subject it to
EPDM composites was investigated. ultrasonic treatment.
Preparation of KKNFs SiO 2 /EPDM nanocomposites:
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1 Experimental part The final dispersion obtained from the previous step was
1.1 Experimental raw materials stirred and dispersed with 800 mL of cyclohexane at 50℃
Ethylene-propylene-diene monomer (EPDM, 4045; for 2 hours to form a stable dispersion. Then, 100 g of EPDM
ethylene content, 47.0%; ENB content, 5.0%) was provided was cut into small pieces and gradually added to the aqueous
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by China Petroleum & Chemical Corporation; Kevlar 49 solution of KKNFs SiO 2 . After mechanical stirring for 12
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yarn was purchased from DuPont; zinc oxide (ZnO) was hours, the KKNFs SiO 2 /EPDM mixed solution was vacuum
provided by Shanghai Jinghua Chemical Reagent Co., Ltd.; distilled at 60℃ until no more cyclohexane condensate was
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stearic acid (StA) was provided by Sinopharm Chemical produced. The obtained wet KKNFs SiO 2 /EPDM material was
Reagent Co., Ltd.; dicumyl peroxide (DCP) was provided vacuum dried at 60℃ until constant weight. The rubber was
by AkzoNobel Chemicals Co., Ltd.; zinc borate (ZB) was mixed on a rubber mill at room temperature, with the feeding
provided by Qingdao Yusuo Chemical Technology Co., Ltd.; sequence being as follows: 100 parts of EPDM, 5 parts of ZnO,
benzoxazine (BA, BZ7413) was provided by Puyang Enying 1 part of StA, 10 parts of ZB, 15 parts of BA, variable amount
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Polymer Materials Co., Ltd.; γ-aminopropyltriethoxysilane of mKNFs SiO 2 or KKNFs SiO 2 , 4.5 parts of DCP, 1 part of
(KH550) was provided by Nanjing Zhongdong Chemical Glass TMTD, and 1.5 parts of S. The rubber compound was allowed
Instrument Co., Ltd.; dimethyl sulfoxide (DMSO), potassium to stand for 24 hours, and the optimal cure time was measured
tert-butoxide (KTB), methanol, cyclohexane, tetraethyl on a vulcanizer at 160℃. Subsequently, an appropriate amount

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