TAP CHi HOA UQC
DOT 10.15625/0866-7144.2015-00170
53(4) 503-508 THANG 8 NAM 2015
NGHIEN CLfU VAI TRO C O A N A N O C L A Y NHU" MOT C H A T
TRa TUONG HOP TRONG BLEND CSTN/EPDM
Le Nhu Da, Daog Vift Hung, U6ng Dinh Long, Nguyen VTnh Dgt, Hoang Nam, Biii Chmmg*
Trung tdm Nghien cuu vgt lieu polyme. Tru&ng Dgi hgc Bdch khoa Ha Ngi Den Tda sogn 26-3-2015; Chip nhgn ddng 26-8-2015
Nanoclay I28E was infroduced in NR/EPDM blends by meh mixing and through masterbatcbs. Its compatibilization effect was evaluated at high deformation (ultimate tensile testmg, saturated swell) and low deformation properties (sfretching - unloading cycles) of filled blends in comparison with that of unfilled one. Results showed that there is ahnost no effect of nanoclay at high deformation degree of mbber blends. In contrary, at low deformation, nanoclay has strong effect on blend properties: the tensile stress of filled blends is higher about 30-60 % than that of unfilled blend, It is assumed that nanoclay being dispersed in mbber matrix at "rough" level - aggregate of 50-100 nm size, has compatibilization effect mainly at low deformation degree of rubber blends.
Keywords. Rubber blends, NR/EPDM blends, nanoclay 128E, deformation.
I.M6DAU
Cao su ty nhien (CSTN) Id mft trong nhung polyme ty nhifn phd biln rgng rdi nhit hifn nay.
Nhd cd cdc tinh chdt ca hgc uu vift nhu do bin co hQC cao, kha nang chju biln dgng chu ky tdt v.v...
CSTN dugc ling dyng trong nhilu nganh kinh tl - ky thugt [I]. Tuy nhien, nhiing nhugc diera nhu chju lao hda nhift, Ido hda thdi tilt kem da hgn chl phan nao ling dyng ciia CSTN.
Nguyen nhdn co bdn ciia khd ndng chiu lao hda k^m ciia CSTN Id do cdc lien kit ddi cd hoat tfnh h6a hpc cao trong phdn tir cua nd. Df khac phyc nhugc dilm ndy, nhifu phuang phap da dugc dp dyng de bien tfnh CSTN, trong dd cd vifc che tao blend CSTN vdi polyme khde, chdng ban polyetylen [2], PVC vd ragt so copolyme [3], cao su clopren [4]. Dgc bift, blend ciia CSTN vd cao su EPDM (CSTN/EPDM blend) rit dugc chii y tron^ vifc chl tgo cdc san pham cao su ky thugt cd dg ben co hgc dgt yeu cdu sii dyng vd kha ndng chju Ido hda cao [5]-
Tuy nhien, do cd dg khde bift rat Idn ve miic dg khdng no trong phdn tii, hai logi cao su CSTN vd EPDM cd khd ndng vd toe dg luu hda khac nhau rit xa [5]. Chfnh vi vgy, CSTN va EPDM khd Urong hgp vdi nhau d l tgo tiianh blend vdi dg bin co hgc chdp nhgn dugc. Da cd nhilu nghien ciiu nhim tdng cudng dg tuong hgp ciia blend CSTN/EPDM. Chdng hgn da thay doi cac hf xiic tiln khde nhau nhdra thay dli toe dg luu hda trong cdc pha CSTN va EPDM
dan den sy ddng deu luu hda trong cac pha [6-8]
bien tinh EPDM hoge CSTN [9, 10]. Sir dyng cdc chit frg tuong hgp khac nhau de tgo lien kit hai pha cao su trong blend [11, 12]. Trong [13] da dua ra nhgn xet vl su djch chuyen xue tifn giira cac pha cao su trong qua frinh tgo blend da lam thay doi dang kl toe dg luu hda ciia cdc cao su frong blend CSTN/EPDM.
Mft xu hudng dang quan tam la sii dyng mgt so chat dgn vd ca de tdng miic dg tuong hgp gi&a hai polyme frong blend. Trong [14] da chi ra rang neu cd sy cdn bdng ve tuang tde giii'a chdt dgn vdi hai polyme, chdt dgn se djnh vj trfn bl mgt tifp xiic hai pha va tao nen su can bang ciia hf thong. Trong [15]
da chi ra vai trd ciia chat d$n nano den hifu qud tuong hgp frong polyme blend. Ching hgn, cac tac gid [16] da danh gia vai tro ciia nanoclay Cloisite I5A den mgt sd tinh chat co hgc cua blend CSTN/EPDM. Da xdc djnh dugc sy tdng cudng tfnh chat CO hgc ciia blend vd cdc kit qua tfnh toan md phdng triing hgp kha tot vdi thye nghifm.
Trong nghien ciiu nay, tde dyng tuong hgp ciia nanoclay dugc danh gla qua miic dg anh hudng cua nd din cdc tinh chdt ciia blend cd nanoclay so vdi blend CSTN/EPDM doi chiing khdng cd nanoclay.
2. THVC NGHIEM 2.1. Nguyen lieu
Cao su ty nhien: logi SVR 3L (Vift Nam) do
TCHH, 53(4), 2015
Cong ty c6 phin cao su chat deo D&i Mo cung cap.
Cao su EPDM: loai V3666 (Hoa Ky) Cac hoa chit khac: ZnO, S, axit stearic, phong lao, XUC tien DM, TMTD, EZ loai ky thuat (Trung Qu6c).
Nanoclay: loai I28E ciia hang Nanocor (Hoa ky) Chit chu masterbatch (MB) I28E: ch6 lao tai Trang tam NCVL Polyrae - Truong Dai hoc Bach Khoa Ha Noi.
2.2. Che tao vat lifu
Vat li?u cao su co don ph6i lieu sau:
Cao su tu nhien (CSTN) Cao su EPDM Nanoclay I28E ZnO Axit stearic Xiic tien DM Xue tien TMTD Phong 150 RD
60 40 3 5 1 1,5 0,7 2
Bid Chuang va cgng su vi tri ban ddu, rdi tiep tyc keo tuong ty vdi tong cdng 3 chu ky fren may INSTRON 5582 (Hoa Ky).
- Xac djnh dg truong: theo tieu chuan TCVN 2572 - 2008 frong toluen.
3. KET QUA VA THAO LUAN
Trong cdng bd trudc day [17] chung tdi da tiidng bdo ring nanoclay I28E phan bo frong nen CSTN cd thi xem nhu mdt chdt dgn nano d hai miic: "mirc thd" - cdc hgt nanoclay vdi kich thudc khoang 50- 100 nm va muc "tinh" hon - sy phan tan ciia silicat xip lap dgng xen ke hoge frdc ]ap. Ty If ciia hai dgng phan tdn nay cdn chua dugc xac djnh, rJiung cd thi thiy anh hudng cua chiing tdi tinh chdt vat lieu la khde nhau.
Trong cdng frinh nay, nanoclay dugc dua vao blend CSTN/EPDM theo hai each d l tgo ra blend 11 va blend HI. Hiin nhien Id frong cdc blend nay cd tbi cd sy phan tdn nanoclay khac nhau theo hai miic do phdn tan ndi tren. Trong hinh I la anh SEM ciia CSTN vdi nanoclay phan tdn tdi miic cac a
Blend CSTN/EPDM dugc hdn luyfn trong may frgn kin BRABENDER D 47055 (Diic) tiieo don phdi lifu nhu tren nhung khdng cd nanoclay I28E,
dugc ggi la blend I. i Nanoclay dugc dua vao blend CSTN/EPDM
theo hai each:
- Dira trye tiep vdo hdn hgp cao su d frang thdi ndng chdy, dugc ggi la blend II.
- Dua vao hon hgp cao su qua chdt chii (MB) vdi tinh todn sao cho hdm lugng nanoclay diing theo don phoi lifu nhu tren, dugc ggi la blend III.
Cd 3 blend deu dugc hdn luyen d nhift dg 110
°C, thdi gian 9 phiit, tde dg trye quay 65 vdng/phiit.
Luu hda d nhift dg 155 "C frong 6 phut.
2.3. Phuong phap thir nghiem
Hmh I. Anh SEM be mgt cat cua CSTN vdi 3 phr nanoclay I28E
- Dg bin keo xdc djnh theo tifu chuin TCVN 3.1. Anh hudng coa nanoclay USE deo d^ tmmg 4509-2006 tren may INSTRON 5582 (Hoa Ky). Tde
dg keo 300 mm/phut.
- Xac djnh vdng fri: dugc thye hifn vdi mdu hrong ty tieu chuin TCVN 4509-2006. Mau dugc keo tdi dg ddn dai 300 % sau dd thao tdi cho frd vl
hgp cQa blend CSTN/EPDM trong toluen Trong bdng I la dg truong cua cac blend II va III Irong toluen. De so sanh, dg truong ciia blend khdng cd nanoclay (blend I) cung dugc dua vao bang I.
Bdng 1: Dg fruang bdo hda trong toluen cua blend CSTN/EPDM cd yk khdng cd nanoclay, % Dp truong bao hoa
Theo khoi luting, % Theo thS tich, %
Blend I 364 367
Blend 11 337 324
Blend UI 341 333
TCHH, 53(4), 2015
Sd lieu bang I cho thdy, vifc dua nanoclay vdo da lam gidm dg truong cua blend CSTN/EPDM mde dil khdng nhilu: khoang 6-7 % (khdi lugng) hoac 10-12 % (thi tich) so vdi blend khdng cd nanoclay (blend I). Cd thi coi miic do gidm do truong bao hda nay la do xuat hifn cac lien kit ciia nanoclay trong nen cao su, bao gom lien kit nanoclay - cao su vd lifn ket clay - clay frong cac tgp hgp hgt (aggregate) frong nen cao su. Miic dg truong bao hda ciing cho
Nghien ciru vai trd cita nanoclay...
thdy mat dg mgng ciia cdc blend II vd III xip xi nhau vd chi cao hon blend I khdng nhilu.
3.2. Anh huomg ciia nanoclay den tinh chit co hoc cua blend CSTN/EPDM
Tfnh chit co hgc ciia cdc blend CSTN/EPDM cd vd khdng cd nanoclay dugc ddnh gid qua cdc dudng cong biln dgng - iing suit (hinh 2).
Hmh 2- Do thj bien dgng - iing sudt ciia blend CSTN/EPDM cd va kbdng cd nanoclay I28E I. Blend I; 2. Blend II; 3. Blend III
Cd the thay nanoclay khdng dnh hudng dang ke dfn gid frj dg ben kfo cua cdc blend, vdo khoang 10,3-10,8 MPa. Tuy nhien, dg ciing (the hifn qua modun vd dg dan dai khi diit) ciia blend cd nanoclay cao hon. Difu nay cho thay cdc lien kft ciia nanoclay cd anh hudng trye tiep den df» ciing nhung ft anh hudng din dg ben frong blend. Ngoai ra, dgng lifn kit ciia ngnoclay cd the cd anh hudng khde nhau.
Dd biet rdng khi dua nanoclay vao nen cao su theo phuong phap frgn hgp ndng chdy, ragt sd hgt nanoclay cd till ton tgi d dgng tap hgp agregat
(aggregate); frong khi dd vifc sii dyng chit chii Idm khd ndng tgo agregat frong blend giara mgnh. Neu so sanh tuong doi cac blend II va blend III, cd thf coi frong blend II cd hai logi lien kit ciia nanoclay: lifn ket nanoclay - cao su va lien ket clay - clay frong agregat. Trong khi do, blend III chi cd lifn kit nanoclay - cao su. Tuong quan ciia hai loai lien kit nay frong blend cd thi danh gia djnh tinh thdng qua khao sat vdng tre ciia chung trong chu ky keo - thao tai ddu tifn (hinh 3).
Tir dd thj tren da xac dinh mgt so thdng sd ciia vdng frf nhu sau (bdng 2).
Bdng 2: Cac thdng so cua vdng frf thir nhit cua cdc blend CSTN/EPDM Thong so
Ong suat keo Dien tich vong tre
Don vj tinh MPa Don vi dien tich
Blend I 3,42 1320
Blend II 4,93 2830
Blend III 4,27 I860 Sd lifu frong bang 2 cho thdy, difn tfch vdng trf ldn so vdi blend I, ddng nghia vdl ndng lugng mit ciia blend II cac hon 2 lan, cdn cua blend III - 1,4 mdt frong chu ky kf o thir nhit cua blend II Id Idn
TCHH, 53(4), 2015
nhit N I U I ^ nai^ higng mit mat cua blend I Iam chuan, tfai sy chenh Ifch nang lucmg cua cac blend n vd in so vdi blend I cd the coi la do lAa hiiy cac Uen kit ciia nanoclay tnmg blend.
Bin Chmmg vd cgng su Trong hf t b ^ g cao su — chit dgn, nang lugng
|rfia h i ^ cac lien k ^ cua fae thdng dugc phdn bd cho tiing logi lien ket theo so dd sau (hieu ung Payne) [18] (hinh 4).
.J.
1 . 3.
^ 2 .
0 -
- D - Blend 111 - o - B l e n d II
^ A - B l e n d l
L ^
c:^^
^ ^ , 3
^ 1
Hinh 3: Vdng frf ciia cac blend CSTN/EPDM 1. Blend L 2. Blend II, 3. Blend m
Hinh 4: So do sy phy thudc cua modun trugt G vao bien do dan ddi cua cao su Trong viing I, su giam nhanh modun G xdy ra do fiha hiiy cdc lien kit ben trong tap hcfp hat chit dgn (lien kit chit dgn - chat dgn). Vimg II dgc trung cho cac lien kit ciia chdt dgn vdi cao su, bao gdm cd lien kit trvc tiep chit dgn — cao su vd hifu iing thiiy dgng. Viing III la cac lien kit cua cao su khdng ddn.
Nhu vdy, sy tang dg cung ciia cac blend cd nanoclay (hinfa 1) la do sy xuat hifn cdc Hen kit ciia nanoclay (Vimg I, II - hinh 4). Khi bi keo dan, cac lien ket ndy bi pha hiiy va tda ra nang lugng tuong irng vdng til. Difn tich vdng tri ciia blend II Idn ban so vdi blend IH chfrng td frong blend CSTN/EPDM, tdng ndng lugng lien kit clay - clay vd clay - cao su cua blend II ldn hon naog lugng lien ket clay — cao
su ciia blend OI. Ndi each khde, phucmg p h ^ dua nanoclay vao blend cd anh hudng den tuong quan giua hai loai lien kit ciia nanoclay frong nen cao su.
Nhgn xet tien cimg phu hgp vdi gia trj ung suat keo ciia cdc blend d chu ky keo thu nhdt (bang 2).
Sau chu ky keo thii nhat, mgt phan Idn cac lien ket nay bi pha vd, do dd iing suat keo d chu ky keo tiiu hai cua cac blend n vd HI gidm mgnh so vdi blend I;
ngodi ra blend II gidm manh ban blend III, tuong ung vdi cac gid tri dien tich vdng tte ndi tren (bang 3).
Miic do gjam iing sudt keo ciia blend I ta do hieu ung lam mem thdng thudng ciia cao su, khi cac lien kit cao su - cao su bj phd vd frong qua trinh keo (hifu ling Patrikeev — Mullins), do do d do bifn dang t h ^ , gia tri nay khdng cao (dudi 10%). Trong cdc blend II va III, do cd them sy pha huy cac tien kit cua nanoclay (hieu iing Payne), iing sudt keo giam manh hon d chu 1^ thu nhdt khoang 15-20 %.
Ngodi ra, sd lifu frong bang 3 cdn cho tiiay anh hudng dang kl cua lien ket clay - clay trong blend II den iing sudt keo so vol blend III: ung suit keo d chu ky keo thii hai cua blend II gidm tdi 20 % so vdi chu ky I, tiong khi d blend III do gidm nay chi khoang 13 %.
Tai chu ky keo thii ba, su giam ting suit keo cua ca ba loai blend CSTN/EPDM deu xip xi nhau, khoang 4 %. Dieu nay chiing td tai biln dgng keo da
, TCHH, 53(4), 2015
H cho, cac lien kit cua nanoclay dd dn djnh va sy dong
^ gdp ciia cac lien kit nay vao vifc tang ling suit keo cua cdc blend II, III la rd rft - khoang 20-30 % so vdi blend I.
Luu y rdng, dg bin kfo ciia cdc blend cd va khdng CO nanoclay xip xi nhu nhau (hmh 1) do dd cd the thay tac dgng tang cudng ciia nanoclay xdy ra
Nghien cuu vai tro cua nanoclay...
ro rft ban d dg biln dgng thip. Tir dd cd the suy doan ring mgc dii nanoclay da dugc phdn tdn trong nfn cao su din cip df nano, nhung mdi chi d miic dg "thd" - cdc tgp hgp hgt cd kich thudc 50-100 nm.
Cac cdu tnic xen ke hoge tdch Idp cua nanoclay frong nln cao su tuy vln cd tde dyng gia cudng, nhung phan ddng gdp cua chOng nhd ban.
Bdng 3: Miic dg giam irng suit keo ciia cac blend CSTN/EPDM theo cdc chu ky keo
Blend CSTN/EPDM
Blend I Blend 11 Blend III
Ung suat keo tai cdc chu ky keo Chu ki I
MPa 3,42 4,93 4,27
100
%
100 100
Chu ki 2 MPa 3,13 4,02 3,74
91,5
%
81,5 87,5
Chu ki 3 MPa 2,98 3,87 3,58
87,1
%
78,5 83,8
m
M
m
0
11)1 iil>
w
4. KET LUAN
Vifc dua nanoclay vao blend CSTN/EPDM cd khd ndng tdng cudng dg tuang hgp giiia hai pha cao su nhd sy xuat hifn cac lifn ket ciia nanoclay. Tuy nhifn, d miic df kfo dan ldn (bien dang khi dirt hodc truong bao hda) dnh hudng ciia cdc lifn ket ndy khdng thi hifn rd.
Vai trd cdc lien ket cd nanoclay thi hifn khd ro d miic dg keo ddn khdng Idn (khodng 50 % biln dgng khi dut). Nguyfn nhan cua hifn tugng ndy Id do raiic df phan tdn ciia nanoclay trong cao su chu yeu mdi d mirc dg thd - cdc tap hgp hgt kfch thudc 50-100 nm, do dd cdc lien kit cua t|lp hgp hgt vdi cao su dl bj phd hiiy d bien dgng Idn.
TAI LI$U THAM K H A O
1. S. Kohjiya, Y. Ikeda. Infroduction, hi the book Chemistry, Manufacture and Application of Nature Rubber, Woodhead Publisbmg Ltd. (2014).
2. Nguyin Quang, D6 Quang Kbdng, Nguyen Vdn Khfii, Phgm Anh Dung, Le Thj MJ Hgnh. Nghien cim dnh hu&ng cua cdng ngh^ trgn hgp din tinh chdt vgt liiu CSTN td hgp v&i LDPE ung dvng ldm vgt Uiu chdng va dgp tau biin, Tgp chf H6a hpc, 39(4B), 46-52 (2001).
3. Nguyen Phi Trung, Thdi Hoang, Vu Minh Diic, Tran Thanh Son. Chi tgo vd nghien cuu tinh chdt vgt lieu blend Iren ca sa CSTN. PVC vd butadien acrylonitril copolyme, Tgp chf Khoa hpc vd Cong nghf, 35(5) 34-37 (1997).
4. Hodng Nam, Trin VTnh Difu, Phgm Anh Tudn, Hd Tbu Hudng, Le Nhu Da. Nghien cim chi tgo vgt li$u blend tren ca s& CSTN vd cao su clopren, Tgp chf Hda hpc, 45(SA), 165-169(2007).
5. Stuart Cook. Solution to the basic problems of poor physical properties of NR/EPDM blends. In book Blends of Natural Rubber, Ed. by Andrew J. Tinker
and Kevin P. Jones. Cbapman&HatI Publisher, London, 169-183(1998).
Ponghom Sae-oui, Cbakrit Sirisinha, Utbai Thepsuvan, Phuchong Thaptbong. Influence of accelerator type on properties of NR/EPDM blends.
Polymer Testing, 26,1062-1067 (2007).
Amp Kumar Ghosh, Subbas Chandra Debrath, Nityananda Naskar, Dipak Kumar Basu. NR-EPDM covulcanizatiom A new approach, J. Applied Polym.
Sci., 81, 800-808 (2001).
Arup Kumar Ghosh, Dipak Kumar Basu. Effect of diisopropyl thiophosphoryl-N-oxydiethilene sunphenamide and some disulphide compounds in covulcanization of NR/EPDM blends. Polymer Intemat, 52,1370-1381 (2003).
A. Mounu El Sayed, H. Afifi. Improvement of Compatibility of NR/EPDM rubber blends via Natural rubber Epoxydation, J. Appl. Polym. Sei., 86,2816-2819(2002).
Alex. S. Sirqueira, Bluma G. Scares. Compatibility of NR/EPDM blends by Anhydride - and mercapto - funetionalized copolymers, 3. Macromol. Sci., Part
B: Physic, 46, 639-650 (2007).
S. H. El - S a b b ^ . Compatibility Study of NR- EPDM rubber blends. Polymer Testing, 22, 93-100 (2003).
M. O. Abou - Helal. A Study on Compatibility of NR/EPDM blends using electrical and mechanical techniques, J. Elastomers and Plastics, 37, 319-346 (2005).
, Le Nbu Da, Dang Viet Hung, Uong Dinh Long, Nguyen Pham Duy Luih, Bui Chuong. Preparation and Characterization of NR/EPDM blends. P.L Effect of mixing Procedures on curative distribution and migration, Viefriam J. CbemisUy, 52(5), 596- 601 (2014).
. Cor Konmg, Martm Van Duin, Cbristophe PagnouIIe, Robert Jerome. Strategies for
507
TCHH, 53(4X2015
Compatibility of Polymer Blends, Process in Polym.
Sci., 23,707-757 (1998).
15. A. Taguet, P.Cassagnau, J. M Lopez - Cuesta.
Structuration. selective dispertion and compmibilizing effect of (nano) fdlers in polymer blends. Progress in Polymer. Sci., 39(8), I526-I563 (2014).
16. Abdobnajid Alipour, Ghasem Naderi, Mir Hamid Reza Gboreirfiy. Effect of nanoclay content and Matrix composition on properties and Stress - strain behavior of NR/EPDM nanocomposites, S. Appl.
Bui Chuang vd cgng su Poiym. Sci., DOI: 10.1002/app. 37752, onUne 19-5- 2012.
Bui Chuong, Dang Viet Hung, Trinh Thi Thu Huong, Doan Yen Oanh, Ta Thi Phuong Hoa. Smdy on Dispersion ofNomxlgy in Natural Rtd)ber (NR) Latex and Its effect on NR vulcanization, Kautschuk - Gummi - Kunstoffe, 7-8, 30-33 (2012).
Uxilenhie Elastomerov, Ed. by G. Kraus (ti«ig Nga), Nxb. Khimia, Moskova, 1968 - Djch tir tilng Anh: Reinforcement of Elastomers, Ed. by G. Kraus, Interscience Publisher.
Liin h?: Biii Chuong
Trang tdm Nghifn ciiu vat lieu polyme Trudng Dgi hgc Bach khoa Ha Ngi Sd I, Dgi C6 Vift, Hai Ba Tnmg, Ha Ngi
E-raail: [email protected]; Difn thogi: 0903446055.
