Effects of several factors on anti–vibration ability of epdm rubber - Phan Quoc Phu

Journal of Science and Technology 55 (1B) (2017) 202–207 EFFECTS OF SEVERAL FACTORS ON ANTI–VIBRATION ABILITY OF EPDM RUBBER Phan Quoc Phu*, Nguyen Khac Tien, La Thi Thai Ha 1Faculty of Materials Technology, HCMUT–VNUHCM 268 Ly Thuong Kiet Street, Ward 14, District 10, Ho Chi Minh City, Vietnam *Email: pqphu@hcmut.edu.vn Received: 30 December 2016; Accepted for publication: 6 March 2017 ABSTRACT In this research, ethylene–propylene–diene (EPDM) rubber, a type of synthetic rubber with excellent anti–vibration and anti–noise properties, was studied for the application in anti–vibration pads. Via changes in the concentration of substances in the mixtures such as carbon black, triethanolamine (TEA) and sulfur, the mechanical properties and the anti–vibration efficiency of the EPDM rubber samples were determined using mechanical tester. As a result, the EPDM rubber samples containing about 45 % of carbon black N330, 1 % of TEA and 1 % of sulfur showed some good results including the shore hardness about 62 A, the compressive stress at peak of 1.04 N/mm2 and the anti–vibration efficiency approximately 72 %. Keywords: EPDM rubber, anti–vibration properties, anti–vibration pads. 1. INTRODUCTION In modern industry, the major problems associated with vibrations such as deterioration mechanisms, productivity decreases and lifetime depression in rotating machines have been indicated. The vibrations have also illustrated serious health effects in humans. Since Cyril M. Harris and Allan G. Pierol wrote the first book to give the concepts of vibration and anti–vibration as well as its application in 1961 [1], there were a lot of significant achievements for minimizing the vibrations such as effect of viscoelastic damper on high–rise buildings during earthquakes [2], viscoelastic material properties for passive vibration damping [3], system dynamics and long–term behaviour of rubber vibrations in scientific research [4], and so on. In Vietnam, there are many companies have manufactured and supplied a wide variety of anti–vibration products from rubber like natural rubber, chloroprene rubber, EPDM rubber, etc. Until recently, however, measures of determining as well as researches related to the anti–vibration ability have not been concentrated, especially no specific survey to determine the current performance of these products in the market. Therefore, this paper focuses on studying the anti–vibration ability of EPDM rubber by research on the effects of some factors including carbon black, TEA and sulfur contents by testing some anti–vibration performances and mechanical properties. Phan Quoc Phu, Nguyen Khac Tien, La Thi Thai Ha 203 2. MATERIALS AND METHODS 2.1. Materials All matrix materials including EPDM rubber, stearic acid, zinc oxide, paraffin, carbon black (N330), 2–mercaptobenzothiazole (MBT), disulfur tetramethylthiuram (TMTD), TEA and sulfur used in this research were bought at Hiep Phat Hung Services Trading Co., Ltd in Ho Chi Minh City, Vietnam. The recipes for the vulcanization system using in this research contained about 100 % EPDM rubber, 3 % zinc oxide, 1 % stearic acid, 2.5 % paraffin, 1.5 % MBT and 1 % TMTD accompanied with the various contents of carbon black, TEA and sulfur. The mixtures were mixed into the EPDM rubber together with the vulcanisation system on the two– roll mill. All materials were vulcanised at 150 °C for 30 min under a pressure of approximately 12 MPa. 2.2. Tensile test Stress–strain properties of the materials were evaluated based on ASTM D 412 using Testometric M350–10CT machine at Faculty of Materials Technology, HCMUT–VNUHCM. The samples were “dog bones” with the cross–section of approximately 2 × 6 mm. The crosshead speed was 500 mm/min. Due to varying degrees of strain of the samples, the stress was considered as a more appropriate property for comparisons than the strain at break. 2.3. Compression test The compression properties of the materials were evaluated using Testometric M350–10CT machine with the crosshead speed was 2 mm/min according to ASTM D 695 at Faculty of Materials Technology, HCMUT–VNUHCM. All samples were cut in cylinders of approximately 20 mm diameter and 12 mm height. Due to the compression test process, the deflection and the force were determined to calculate the stiffness (K), the natural frequency (fn), the forced frequency (fd), the transmission coefficient (T) and the anti–vibration performance (H) according to some of the formulas below [1, 5]: ○ K = F/d ○ fn = 3.13 x (K/W)1/2 ○ fd = fmin/60 ○ T = ((fd/fn)2 – 1)–1 ○ H = (1–T) x 100 (%) Where: F is the force corresponding to the static deflection (N), d is the static deflection (mm), W is the design load (15 kg) and fmin is the Duress frequency (60 Hz). 2.4. Density measurement Density measurements were performed on all samples in the research related to TEA concentration. Collecting data for results from measurements upon TCVN 3976-1984 at Faculty of Materials Technology, the density was calculated by applying the Archimedes principle according to the formula: Density = Pa / (Pa – (Pe – go). With: Pa is the mass of the rubber sample in the air, Pe is the mass of the rubber sample in water and the density of water (about 1 g/cm3). 2.5. Morphological studies Eff 20 EP La 3.1 lev we ects of seve 4 Scanning DM rubber boratory for . TEA conte In this su el of fillers re presented Figure 1 Figure 2. S Figur ral factors o electron mi morphology Nanotechno nt rvey, the am and sulfur w in Figure 1 . Hardness Sh tress at 300% e 3. SEM ima n anti–vibrat croscope (S by observa logy in Viet 3. RESU ounts of TE ere fixed ab . ore A (a) and (a) and Youn ge at a magn the 1. ion ability of EM) was u tions of the nam Nationa LTS AND A were cha out 50 % an density (b) o g module (b) ification of 20 5 % TEA am EPDM rubb sed to analy cross–sect l University DISCUSSI nged from 0 d 1 %, respe f the samples of the sampl 00 at the cen ount sample. er ze how the ionals by SE HCM City. ON % to 1.5 % ctively. The with differen es with differe ter (a) and the TEA effect M JSM–64 whilst the measureme t TEA amoun nt TEA amo outer (b) of s on the 80LV at selected nt results ts. unts. TE 62 sam fro for de 30 lar S 0 1 Ta pe 1.5 the va low 3.2 of for me Wh va As can be A contents w Shore A w ples also r m 0 % to mation of composition 0% and You ge porous fo T ample Fo 0.1 0% 52 .5% 52 1% 49 .5% 49 Fig Besides t ble 1 and F ak rose and % TEA am 1 % TEA a lues were de est value at . Sulfur con One of th rubber mole enhancing chanical pro The bar c en the sulfu lue by about seen from t ere increas ith 1.5 % TE educed from 1.5 %. The foam struct process of ng module v aming in the able 1. The co rce at mm (N) C str .870 .514 .113 .767 ure 4. Stress hat, the com igure 4. Wh hit the highe ount sample mount samp creased whe 491.1 N/mm tent e most impo cules. In this the mechani perties of th hart in Figu r contents w 69 Shore A he Figure 1 ed. Particula A. Besides 1.064 g/cm decrease o ure in the TEA. In par alues of the center of th mpression m ompressive ess at peaks (N/mm2) 1.09 1.12 1.32 1.24 at peak (a), st the sample pression m ile the TEA st value at (Figure 4a) le also show n the TEA with the op rtant factors experiment cal propertie ese samples re 5a gave ere increase with 2 % s Phan Q a, the hardne rly, the lowe that, Figure 3 to 1.032 f the hardn sample cau ticular, the sample with is sample (F easurement d Stiffness K (N/mm) 528.7 525.1 491.1 497.7 iffness K (b) a s with differe easurement contents w 1.32 N/mm2 . Furthermo n the highes levels rose u posite trend related to th , three level s and anti–v were shown the compari d, the hardn ulfur in the uoc Phu, N ss values of st value of t 1b showed g/cm3 when ess and den sed by the results in Fi 1.5 % TEA igure 3). ata of the var Natural frequency (Hz) 29.88 29.78 28.80 29.00 nd anti–vibra nt TEA amou data illustr ere increased , and then d re, the resul t anti–vibra p to 1.5 %. . e anti–vibra s of sulfur (1 ibration abi by the bar c son of the h ess results a sample. Bec guyen Khac the samples he hardness that the de the TEA co sity results generated gure 2 show reduced rap ious amounts Transmis coefficie 0.33 0.33 0.30 0.31 tion performa nts. ated the op from 0 % ecreased to ts in the Figu tion perform In contrast, tion perform %, 1.5 % a lities of the harts in Figu ardness and lso increase ause of the i Tien, La Th decreased was reached nsity values ntent was i were relate gases from ed that the idly because of TEA. sion nt Anti–v perfo ( nce (c) of posite resul to 1 %, the 1.24 N/mm2 re 4c illustr ance at 70 % the stiffnes ance is the f nd 2 %) wer rubber samp re 5. the sulfur d and got th ncrease of t i Thai Ha 205 when the at about of these ncreased d to the thermal stress at of some ibration rmance %) 67 67 70 69 ts in the stress at with the ated that and the s got the lexibility e studied les. The contents. e highest he sulfur Eff 20 con Yo sm 2.1 the app sul we the S ects of seve 6 tent, the cro ung module allest value Figure 5. H Figure Observing 6 N/mm2 to increase of eared the s fur were ad re appearan stress at 30 Ta ample Fo 0.1 1% 49 1.5% 52 2% 51 Figure 7. St ral factors o ss–linkings result show of 2.64 N/m ardness Sho 6. The photo o the bar ch 2.38 N/mm the cross–l urface bloom ded to the m ce of excess 0 %. ble 2. The co rce at mm (N) C str .113 .252 .191 ress at peak ( n anti–vibrat in the rubbe ed the oppos m2 at the 2 % re A (a), stres di f the surface art in the 2 when the inkings. The phenomen ixture rubbe sulfur amou mpression m ompressive ess at peaks (N/mm2) 1.32 1.37 1.33 a), stiffness K di ion ability of r were built ite trend com sulfur cont s at 300 % (a fferent sulfur bloom pheno Figure 5b, sulfur amou 2 % sulfur on (Figure r, besides pr nts probably easurement d Stiffness K (N/mm) 491.1 522.5 511.9 (b) and anti– fferent sulfur EPDM rubb up causing t pared with ent sample. ) and Young m contents. menon of the the stress a nts were inc sample, ho 6). Therefor esenting the acting like ata of the vari Natural frequency (Hz) 28.8 29.7 29.4 vibration per amounts. er he higher ha the Shore A odule (b) of 2 % sulfur co t 300 % re reased from wever, got t e, when the forming of plasticiser ca ous amounts o Transmiss coefficien 0.30 0.32 0.32 formance(c) o rdness. How Hardness an the samples w ntent sample sults increas 1% to 1.5 he lowest s high amoun cross–linkin used the de f sulfur. ion t Anti–v perfo ( f the samples ever, the d hit the ith s. ed from % due to tress and ts of the gs, there crease of ibration rmance %) 70 68 68 with the the low res eff per 3.3 the res an 2.2 low fill ind car par ab res tha com Sa 4 5 5 The comp Figure 7a s stiffness K er anti–vib ults indicate ects on the formance. . N330 carb Carbon bl amounts of earch were f Figure 8. H When the d the stress a 3 N/mm2, r er than the er occurring In additio icated that bon black ticular, the out 72 % and ults in the F n the 50 % c pound. Table mple F 0 5% 4 0% 4 5% 5 ression test hown that th by 1.37 N ration perfor d that only mechanica on black co ack is one o carbon blac ixed with 10 ardness Sho filler conte t 300 % val espectively. value of the the excess c n, the result the stiffness were increa sample with the lowest igure 9a illu arbon black 3. The comp orce at .1 mm (N) 6.187 9.113 2.870 results were e 1.5 % sul /mm2 and 5 mance comp the minor c l properties ntent f the major k from 45 % 0 % EPDM re A (a), stres differ nts of the m ues increase However, th 50 % carbo ontaining in s obtained fr K values o sed leading 45 % carbon stiffness val strated that sample bec ression measu Compressiv stress at peak (N/mm2) 1.04 1.32 1.20 Phan Q also presen fur sample g 22.2 N/mm, ared with th hanges in th but showed factors affec to 55 %, th . The mecha s at 300 % (a ent carbon bla ixtures were d and reache e Young m n black sam the 55 % ca om the com f these sam to the dec black show ue at approx the stress at ause of a sm rement data e s Stiffnes K (N/mm) 461.5 491.1 528.7 uoc Phu, N ted in Table ot the highe respectivel e value of t e sulfur con very little ting to the p e other comp nical proper ) and Young m ck amounts. increased f d the highes odule value ple, probab rbon black s pressed mea ples were r rease of the ed the highe imately 461 peak of thi all shortage of the various s Natural frequency (Hz) 27.9 28.8 29.9 guyen Khac 2 and Figu st value of t y. However, he 1 % sulfu tent in the r variation i roperties of onents in th ties were pre odule (b) of rom 45 % to t results at a of this sam ly because o ample. surement in un up when anti–vibrat st anti–vibr .5 N/mm (Ta s sample sho of this filler amounts of c Transmiscoefficie 0.28 0.30 0.33 Tien, La Th re 7. The ba he stress at this sampl r sample. T ubber gave n the anti– rubber. By e recipes usi sented in Fi the samples w 50 %, the bout 74 Sho ple was sign f the overu Table 3 and the amoun ion perform ation perform ble 3). How wed the low amount in th arbon black. sion nt Anti–v perfo ( i Thai Ha 207 r chat in peak and e got the herefore, the high vibration changing ng in the gure 8. ith hardness re A and ificantly se of this Figure 9 ts of the ance. In ance by ever, the er value e rubber ibration rmance %) 72 70 67 Eff 20 sam con the of eff we bu req va go res con 1 2 3 4 5 ects of seve 8 Figure 9. St The resul ple by usi tents to cha sulfur linka the filler wi ects of chan re done whe t also the uirements o lues of the sa t the best p earch, there taining carb . Cyril M edition, . Fuyuki A velocity building . Ambesh improve Compos . Xiu–Yin propertie Purificat . David Fr Technol ral factors o ress at peak ( ts in this st ng TEA to nge the amo ges between th the rubber ging a lot of re the EPDM effective pe f the anti–vi mple with t roperties at are nume on black in . Harris, Al R. R. Donne dachi, Koh on optimal s, Engineerin Kumar, Sa d free/cons ites Part B: E g Zhao, Ya– s of nitril ion Technol ankovich – ogies, 2009. n anti–vibrat a), stiffness K di 4. udy indicate make the p unt of cross the chains o matrix), the parameters, rubber sa rformance bration rubb he recipe usi approximat rous applica building con lan G. Pier lley & Sons ei Fujita, M along–heig g Structure tyajit Panda trained laye ngineering Jun Cao, H e–butadiene ogy 123 (20 The Basics o ion ability of (b) and anti– fferent sulfur CONCLU d that, by t orous struct –linking in f the rubber anti–vibrat some comp mple showe of the anti– er pads, the ng with abo ely 62 Sho tions for a struction, m REFEREN ol – Harris Company, 2 asaaki Tsuj ht allocation s 56 (2013) 4 – Design r passive 96 (2016) 20 ua Zou, Jing rubber/hin 12) 3696–37 f Vibration EPDM rubb vibration per amounts. SIONS he way of ure or alter the compou molecules a ion ability c arative analy d up not onl vibration a hardness an ut 45% carb re A and 7 nti–vibration achine techn CES ’ Shock and 002, pp. 145 i, Izuru Tak of viscous 89–500. of a 1–3 v damping tre 4–214. Li, Li–Qun dered phen 02. Isolation Us er formance(c) o changing the ing the sulf nd (the stron nd the stron an be modif sis for the s y the high m bility. In c d the anti–v on black, 1% 2%, respecti systems u iques, envir anti–vibrat 6. ewaki – Imp oil damper iscoelastic atment of Zhang – St ol composi ing Elastom f the samples morpholog ur and carb g chemical g interfacial ied. Accordi elections of echanical p omparison ibration perf TEA and 1 vely. Based sing EPDM onment and ion handbo ortance of i s in super composite structural v ructure and tes, Separa eric Materia with y in the on black bonds of bonding ng to the materials roperties with the ormance % sulfur on this rubber health. ok, Fifth nterstory high–rise layer for ibration, dynamic tion and ls, Aearo