Preparation and properties of cellulose isocyanate based lubricating grease
-
摘要: 随着石化资源的日益枯竭以及人们环保意识的提高，润滑脂的绿色可持续发展迫在眉睫。本文以天然可再生的微晶纤维素为原料，对其进行表面异氰酸酯化改性进而制备了环保型纤维素基润滑脂。采用FTIR、SEM、XRD以及TG等手段分析了纤维素表面的接枝效果。利用流变仪和四球摩擦试验机系统研究了纤维素基润滑脂的流变特性和摩擦学性能。研究结果表明：纤维素经过异氰酸酯改性后，极大地提高了其对基础油的增稠能力。相较于纯纤维素基润滑脂，改性纤维素基润滑脂的抗剪切能力得到了提升，临界点和流动点显著增加。并且，两种润滑脂表现出相似的粘弹性规律，在0~50 ℃范围内，线性粘弹性函数随温度升高而下降；在50~100 ℃范围内，线性粘弹性函数则随温度升高而升高。改性纤维素基润滑脂的抗磨性有所提高，磨斑直径从0.873 mm下降到0.820 mm。该工作为环保型润滑脂的制备提供了创新思路。Abstract: With the increasing depletion of petrochemical resources and the improvement of people's awareness of environmental protection, the green and sustainable development of grease is extremely urgent. In this study, environmental-friendly cellulose-based lubricating grease was prepared by surface isocyanate modification using natural and renewable microcrystalline cellulose as raw material. The grafting effect on the surface of cellulose was analyzed using FTIR, SEM, XRD, and TG methods. The rheological and tribological properties of cellulose based lubricating grease were studied using a rheometer and a four ball tribotester. The research results indicate that after modification with isocyanate, cellulose greatly improves its thickening ability on base oil. Compared to pure cellulose-based grease, the shear resistance of modified cellulose-based grease has been improved, and the critical point and flow point are significantly increased. Moreover, the two types of lubricating greases exhibit similar viscoelastic laws, with a linear viscoelastic function decreasing with increasing temperature in the range of 0-50 ℃; In the range of 50-100 ℃, the linear viscoelastic function increases with increasing temperature. The wear resistance of modified cellulose-based grease has been improved, and the wear spot diameter has decreased from 0.873 mm to 0.820 mm.
-
Key words:
- lubricating greases /
- cellulose /
- isocyanation /
- rheological properties /
- tribology
-
图 1 微晶纤维素(MCC)-二苯基甲烷二异氰酸酯(MDI)的合成示意图
Figure 1. Schematic diagram of the synthesis of microcrystalline cellulose (MCC)-Diphenylmethane diisocyanate (MDI)
图 3 (a, b)MCC和(d, e)MCC-MDI的SEM图；(c)MCC和(f)MCC-MDI的EDS图；(g-i)MCC-MDI的元素Mapping图
Figure 3. SEM micrographs of (a, b) MCC and (d, e) MCC-MDI; EDS images of (c) MCC and (f) MCC-MDI; elemental Mapping images of MCC-MDI
图 4 (a, b) MDI、MCC、MCC-MDI以及(c, d)润滑脂的TG和DTG曲线
Figure 4. TG and DTG curves of (a, b) MDI、MCC、MCC-MDI and (c, d) lubricating grease
图 5 MCC/O和MCC-MDI/O的(a)表观粘度(η)和(b)剪切应力(τ)随剪切速率(γ)的扫描图
Figure 5. The (a) apparent viscosity (η) and (b) shear stress (τ) of MCC/O and MCC-MDI/O with the shear rate (γ) sweep
图 6 (a) MCC/O和(b) MCC-MDI/O的触变测试
Figure 6. Thixotropic test of (a) MCC/O and (b) MCC-MDI/O
图 7 (a) MCC/O和(b) MCC-MDI/O的应变扫描
Figure 7. Strain sweep of (a) MCC/O and (b) MCC-MDI/O
图 8 MCC/O和MCC-MDI/O的(a)储能模量(G')、损耗模量(G'')以及(b)损耗因子随角频率ω的变化规律
Figure 8. Frequency dependence of (a) storage modulus (G'), loss modulus (G'') and (b) loss tangent ω for MCC/O and MCC-MDI/O
图 9 (a, b)MCC/O和(c, d)MCC-MDI/O在不同温度下的G´、G´´以及ω的变化规律
Figure 9. Frequency dependence of G´, G´´ and ω for (a, b) MCC/O and (c, d) MCC-MDI/O at different temperature
图 10 MCC/O、MCC-MDI/O以及MCC-MDI-ODA/O润滑过的钢球磨斑照片
Figure 10. Photo of wear spots on steel balls lubricated with MCC/O, MCC-MDI/O and MCC-MDI-ODA/O
图 11 MCC-MDI/O在逐量加入十八胺后的红外图
Figure 11. FTIR characterization of MCC-MDI/O after gradually adding octadecylamine
图 12 MCC/O、MCC-MDI/O以及MCC-MDI-ODA/O的外观以及内部结构示意图
Figure 12. Appearance and internal structure diagram of MCC/O, MCC-MDI/O and MCC-MDI-ODA/O
表 1 MDI、MCC、MCC-MDI以及润滑脂的TGA数据
Table 1. TGA characteristic parameters for the MDI、MCC、MCC-MDI and lubricating grease
Samples T5% /℃ Tmax /℃ Yc /% MDI 169.0 262.5 1.8 MCC 271.2 350.7 4.3 MCC-MDI 290.1 347.7/373.0 14.3 MCC/O 296.1 352.8/424.8 2.3 MCC-MD/O 298.7 369.5/424.5 3.3 Notes: T5%－Onset degradation temperature; Tmax－Maximum decomposition; Yc－Char yield at 800 oC 
下载: 导出CSV
表 2 MCC/O、MCC-MDI/O以及MCC-MDI-ODA/O的摩擦学性能表
Table 2. Friction performance of MCC/O, MCC-MDI/O and MCC-MDI-ODA/O
Samples Friction coefficient Friction force/N Wear scar diameter/mm MCC/O 0.077 3.783 0.873±0.075 MCC-MDI/O 0.113 5.542 0.820±0.062 MCC-MDI-ODA/O 0.085 4.169 0.455±0.037
下载: 导出CSV
表 3 与其他生物质基润滑脂的摩擦学性能对比
Table 3. Comparison of friction performance with other bio-based lubricants
Thickener type Friction coefficient Ref. Montmorillonite/cellulose 0.095 [21] Cellulose pulp 0.086 [22] Ethylcellulose nanofibrous 0.075 [23] Barley straws 0.092 [24] Wheat straws 0.095 [24] Epoxidized lignocellulosic 0.12 [25] Eucalyptus lignin/cellulose acetate 0.092 [26] Poplar lignin/cellulose acetate 0.076 [26] Olive lignin/cellulose acetate 0.070 [26] Kraft lignin/cellulose acetate 0.067 [27] Kraft lignin/ethylcellulose 0.088 [28] Alkylated lignin 0.097 [29] NCO-functionalized lignin 0.083~0.089 [30] Acylated chitosan 0.12 [31] MCC-MDI 0.085 This work
下载: 导出CSV
-
[1] 楼高波, 张恒, 饶青青, 等. 生物基阻燃剂在环氧树脂中的应用研究进展[J]. 林业工程学报, 2023, 8(5): 13-26.LOU G B, ZHANG H, RAO Q Q, et, al. Recent advances of application of bio-based flame retardant in epoxy resin[J]. Journal of Forestry Engineering, 2023, 8(5): 13-26(in Chinese) [2] LOU G B, Ma Z, DAO J, et al. Fully biobased surface-functionalized microcrystalline cellulose via green self-assembly toward fire-retardant, strong, and tough epoxy biocomposites[J]. ACS Sustainable Chemistry & Engineering, 2021, 9(40): 13595-13605. [3] LOU G B, PEI G, WU Y T, et al. Combustion conversion of wood to N, O co-doped 2D carbon nanosheets for zinc-ion hybrid supercapacitors[J]. Chemical Engineering Journal, 2021, 413: 127502. doi: 10.1016/j.cej.2020.127502 [4] WU Z P, THORESEN P P, MATSAKAS L, et al. Facile synthesis of lignin-castor oil-Based oleogels as green lubricating greases with excellent lubricating and antioxidation properties[J]. ACS Sustainable Chemistry & Engineering, 2023, 11(34): 12552-12561. [5] SANCHEZ R, ALONSO G, VALENCIA C, et al. Rheological and TGA study of acylated chitosan gel-like dispersions in castor oil: Influence of acyl substituent and acylation protocol[J]. Chemical Engineering Research and Design, 2015, 100: 170-178. doi: 10.1016/j.cherd.2015.05.022 [6] YI T, ZHAO H Y, MO Q, et al. From cellulose to cellulose nanofibrils—A comprehensive review of the preparation and modification of cellulose nanofibrils[J]. Materials, 2020, 13(22): 5062. doi: 10.3390/ma13225062 [7] NECHYPORCHUK O, BELGACEM M N, BRAS J. Production of cellulose nanofibrils: A review of recent advances[J]. Industrial Crops and Products, 2016, 93: 2-25. doi: 10.1016/j.indcrop.2016.02.016 [8] KE W T, CHIU H L, LIAO Y C. Multifunctionalized cellulose nanofiber for water-repellent and wash-sustainable coatings on fabrics[J]. Langmuir, 2020, 36(28): 8144-8151. doi: 10.1021/acs.langmuir.0c01145 [9] OBERLINTNER A, LIKOZAR B, NOVAK U. Hydrophobic functionalization reactions of structured cellulose nanomaterials: Mechanisms, kinetics and in silico multi-scale models[J]. Carbohydrate Polymers, 2021, 259: 117742. doi: 10.1016/j.carbpol.2021.117742 [10] SOUZA G D, BELGACEM M N, GANDINI A, et al. Synthesis and characterization of nanofibrilated cellulose films modified with blocked isocyanates in aqueous media and their barrier properties to water vapor and oxygen[J]. Carbohydrate Polymer Technologies and Applications, 2022, 4: 100249. doi: 10.1016/j.carpta.2022.100249 [11] GALLEGO R, ARTEAGA J F, VALENCIA C, et al. Chemical modification of methyl cellulose with HMDI to modulate the thickening properties in castor oil[J]. Cellulose, 2013, 20(1): 495-507. doi: 10.1007/s10570-012-9803-4 [12] XING L D, HU C S, ZHANG W W, et al. Transition of cellulose supramolecular structure during concentrated acid treatment and its implication for cellulose nanocrystal yield[J]. Carbohydrate Polymers, 2020, 229: 115539. doi: 10.1016/j.carbpol.2019.115539 [13] WANG Y, ZHANG P, LIN J, et al. Rheological and tribological properties of lithium grease and polyurea grease with different consistencies[J]. Coatings, 2022, 12(4): 527. doi: 10.3390/coatings12040527 [14] DAI W T, ZUO J H, LIU D H, et al. Tribological properties and seasonal freezing damage evolution of rotating spherical hinge self-lubricating coating[J]. Applied Sciences, 2022, 12(16): 8329. doi: 10.3390/app12168329 [15] REN G L, ZHOU C J, WANG S Y, et al. Improving the rheological and tribological properties of lithium complex grease via complexing agent[J]. Tribology International, 2022, 175: 107826. doi: 10.1016/j.triboint.2022.107826 [16] LI Y, ZHOU W D, XUE W A, et al. The enhancement of overall performance of lubricating grease by adding layered double hydroxides[J]. Lubricants, 2023, 11(6): 260. doi: 10.3390/lubricants11060260 [17] ZAKANI B, ANSARI M, GRECOV D. Dynamic rheological properties of a fumed silica grease[J]. Rheologica Acta, 2018, 57(1): 83-94. doi: 10.1007/s00397-017-1064-6 [18] BARTOLOME M, GONCALVES D, TUERO A G, et al. Greases additised with phosphonium-based ionic liquids - Part I: Rheology, lubricant film thickness and Stribeck curves[J]. Tribology International, 2021, 156: 106851. doi: 10.1016/j.triboint.2020.106851 [19] GALLEGO R, ARTEAGA J F, VALENCIA C, et al. Thickening properties of several NCO-functionalized cellulose derivatives in castor oil[J]. Chemical Engineering Science, 2015, 134: 260-268. doi: 10.1016/j.ces.2015.05.007 [20] SANCHEZ R, FRANCO J M, DELGADO M A, et al. Rheological and mechanical properties of oleogels based on castor oil and cellulosic derivatives potentially applicable as bio-lubricating greases: Influence of cellulosic derivatives concentration ratio[J]. Journal of Industrial and Engineering Chemistry, 2011, 17(4): 705-711. doi: 10.1016/j.jiec.2011.05.019 [21] GORBACHEVA S N, YARMUSH Y M, ILYIN S O. Rheology and tribology of ester-based greases with microcrystalline cellulose and organomodified montmorillonite[J]. Tribology International, 2020, 148: 106318. doi: 10.1016/j.triboint.2020.106318 [22] MARTIN-ALFONSO J E, LOPEZ-BELTRAN F, VALENCIA C, et al. Effect of an alkali treatment on the development of cellulose pulp-based gel-like dispersions in vegetable oil for use as lubricants[J]. Tribology International, 2018, 123: 329-336. doi: 10.1016/j.triboint.2018.02.027 [23] BORREGO M, MARTIN-ALFONSO J E, VALENCIA C, et al. Developing electrospun ethylcellulose nanofibrous webs: An alternative approach for structuring castor oil[J]. ACS Applied Polymer Materials, 2022, 4(10): 7217-7227. doi: 10.1021/acsapm.2c01090 [24] BORRERO-LOPEZ A M, BLANQUEZ A, VALENCIA C, et al. Influence of solid-state fermentation with Streptomyces on the ability of wheat and barley straws to thicken castor oil for lubricating purposes[J]. Industrial Crops and Products, 2019, 140: 111625. doi: 10.1016/j.indcrop.2019.111625 [25] CORTES-TRIVINO E, VALENCIA C, DELGADO M A, et al. Thermo-rheological and tribological properties of novel bio-lubricating greases thickened with epoxidized lignocellulosic materials[J]. Journal of Industrial and Engineering Chemistry, 2019, 80: 626-632. doi: 10.1016/j.jiec.2019.08.052 [26] RUBIO-VALLE J F, VALENCIA C, SANCHEZ M, et al. Oil structuring properties of electrospun Kraft lignin/cellulose acetate nanofibers for lubricating applications: influence of lignin source and lignin/cellulose acetate ratio[J]. Cellulose, 2023, 30(3): 1553-1566. doi: 10.1007/s10570-022-04963-2 [27] RUBIO-VALLE J F, SANCHEZ M C, VALENCIA C, et al. Production of lignin/cellulose acetate fiber-bead structures by electrospinning and exploration of their potential as green structuring agents for vegetable lubricating oils[J]. Industrial Crops and Products, 2022, 188: 115579. doi: 10.1016/j.indcrop.2022.115579 [28] BORREGO M, MARTIN -ALFONSO J E, VALENCIA C, et al. Impact of the morphology of electrospun lignin/ethylcellulose nanostructures on their capacity to thicken castor oil[J]. Polymers, 2022, 14(21): 4741. doi: 10.3390/polym14214741 [29] WU Z, THORESEN P P, MATSAKAS L, et al. Facile synthesis of lignin-castor oil-Based oleogels as green lubricating greases with excellent lubricating and antioxidation properties[J]. ACS Sustainable Chemistry & Engineering, 2023, 11(34): 12552-12561. [30] BORRERO-LOPEZ A M, SANTIAGO-MEDINA F J, VALENCIA C, et al. Valorization of kraft lignin as thickener in castor oil for lubricant applications[J]. Journal of Renewable Materials, 2018, 6(4): 347-361. doi: 10.7569/JRM.2017.634160 [31] SANCHEZ R, STRINGARI G B, FRANCO J M, et al. Use of chitin, chitosan and acylated derivatives as thickener agents of vegetable oils for bio-lubricant applications[J]. Carbohydrate Polymers, 2011, 85(3): 705-714. doi: 10.1016/j.carbpol.2011.03.049 -
下载:
点击查看大图
计量
- 文章访问数: 52
- HTML全文浏览量: 34
- 被引次数: 0
