空心玻璃微珠改性对喷涂型环氧涂层性能影响OA北大核心CSTPCD
Effect of Hollow Glass Microspheres Modification on Spray-type Epoxy Coating Properties
目的 通过表面改性提升空心玻璃微珠(HGM)在喷涂型环氧涂层中的分散性并提升涂层性能.方法 应用KH560作为桥联单元,链接NaOH刻蚀后HGM表面的羟基与CTPB的端羧基,制备HGM-CTPB.应用SEM、FTIR、TGA和UV对过程中各表面改性HGM的表面形貌、接枝基团及在环氧涂层中的分散性进行分析,并将HGM-CTPB作为低密度填料加入环氧涂层中,研究其添加量对涂层的附着力、柔韧性、耐冲击性、表面粗糙度以及耐腐蚀性能的影响.结果 CTPB可通过KH560成功桥接在NaOH刻蚀过的HGM表面,所制备的HGM-CTPB相较于HGM本身、NaOH刻蚀HGM以及KH560接枝改性的HGM可在环氧涂层中实现更为均匀的分散,同时CTPB基团可与树脂分子反应将HGM牢固锚定.将HGM-CTPB作为填料,其添加量与环氧树脂质量比为0.08和0.16时,所制备的环氧涂层性能较优.面密度较纯环氧涂层分别降低5.6%和11.3%;涂层附着力分别提高0.97、2.14 MPa,达到15.57、16.74 MPa,依据国标方法,涂层可耐50 cm·kg的正、反向冲击,柔韧性达到1 mm;在60℃,浓度为5%(质量分数)的热盐水中浸泡144 h后,低频阻抗可以保持在108Ω以上,较纯环氧涂层提升2个数量级.结论 CTPB的成功接枝可以使HGM在环氧涂层中实现最优的分散性,并与树脂基体实现良好结合;适量添加HGM-CTPB,可显著降低环氧涂层面密度,提升附着力和耐腐蚀性.
To improve the dispersion of hollow glass microspheres (HGM) in the spray-type epoxy coating by surface modification and analyze the effect of modified HGM on the coating performance,in this paper,KH560 was used as the bridging unit linked to the hydroxyl group on the surface of HGM after NaOH etching with the terminal carboxyl group of CTPB to prepare HGM-CTPB.The surface morphology,grafting groups,and dispersion in the epoxy matrix of each surface-modified HGM were analyzed by SEM,FTIR,TGA,and UV.Then,HGM-CTPB was added as a low-density filler into the epoxy matrix,and the effects on the adhesion,flexibility,impact resistance,surface roughness,and corrosion resistance were studied.According to the analysis result,the characteristic peaks of—C═C—and—CH2 belonging to CTPB could be seen respectively in the FT-IR spectra of HGM-CTPB which were located at 3100-3000 cm-1 and 3000-2700 cm-1.In thermogravimetric analysis,HGM-CTPB lost the highest mass,reaching 7.2%,and HGM-CTPB had the fastest weight loss rate during the heating process from 200 to 500 ℃,mainly due to the largest molecular weight of the CTPB segment grafted with HGM after the sample was removed by the bound water addition.An obvious morphological difference between HGM-CTPB and bare HGM could also be seen in the SEM images.Such results proved that KH560 could successfully bridge CTPB to the surface of NaOH-etched HGM.Through the SEM images of the cross section of coatings,HGM-CTPB could achieve better dispersion without migration and enrichment in the epoxy matrix compared with bare HGM,NaOH-etched HGM,and KH560 grafted HGM,which were also confirmed by the coating transmittance curve.The result showed that CTPB groups could provide sufficient steric hindrance for dispersion and react with epoxy groups to firmly anchor HGM.The epoxy coating prepared performed best when HGM-CTPB was used as filler and its additional mass ratio of epoxy resin was 0.08 and 0.16.The density was 5.6% and 11.3% lower than the pure epoxy coating;Where the average adhesion was increased by 0.97 and 2.14 MPa,reaching 15.57 and 16.74 MPa.Such coatings could withstand forward and reverse impacts of 50 cm·kg,and 1 mm flexibility was passed without cracks.After soaking in 5wt.% NaCl solution at 60 ℃ for 144 h,low-frequency impedance could be maintained above 108 Ω,which was 2 orders of magnitude higher than the pure epoxy coating.Above all,the successful grafting of CTPB can enable HGM to achieve optimal dispersion and a good combination with the epoxy matrix.The density of fabricated coatings can be significantly reduced,while the adhesion and anti-corrosion properties can be improved with a proper amount of HGM-CTPB.At present,epoxy-based protective coatings for large-scale equipment are mostly applied by the spraying process.This study provides a new strategy for the lightweight of such coatings,which can effectively solve the serious migration and phase separation problems of low-density fillers in the dilution,especially during the curing process,due to the low viscosity of the epoxy matrix,so as to ensure the performance and uniformity of coatings.
邓龙;贺辉;张立国;关振威;王智勇
中国航发北京航空材料研究院,北京 100095航空工业第一飞机设计研究院,西安 710089
金属材料
空心玻璃微珠环氧涂层填料改性端羧基聚丁二烯低密度附着力防腐蚀性能
hollow glass microspheresepoxy coatingfiller modificationterminal carboxyl polybutadienelow densityadhesionanti-corrosion properties
《表面技术》 2024 (016)
129-138 / 10
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