TAP CHI HOA HOC
DOI: 1015625/0866-7144.2014-0073
T. 52(6) 780-783 T H A N G I 2 N A . ^ ^ ^ 0 1 4
NGHIEN CIJU CH^ TAO VAT LIEU POLYME COMPOZIT TU' H$ NHLTA EPOXY/MHHPA GIA CU'aNG SOl" T H O Y TINH CO MAT VI SOI XENLULO
Phin 2. K H A O S A T ANH HU-eyNG CLIA HAM LlTaNG VA KJCH THUOC VI SOI XENLULO D^N MLFC DO DONG RAN C O A NHIJA EPOXY
Phan Thi Minh Ngoc', Vu Minh Dure'", Phgm Thi Lanh', Doan Thj Yen Oanh^ Ha Thi Ha' Trung tdm Nghien cuu vdt lieu polyme. Tnrdng Bgi hgc Bdch khoa Hd Ndi 'Nha Xudt bdn Khoa hgc tu nhien vd Cdng nghe. Vi?n Hdn Idm Khoa hgc vd Cong nghe Viet Nam
Bin Tda soan 7-10-2014; Chip nhan dang 4-12-2014
Abstract
In this sUidy, effects of contents and size of bacterial cellulose (DC) to the curing kinetics of glycidyl ether of bisphenol A (DGEBA) using 4-methyl hexahydrophtalic anhydrite (MHHPA) as a curing agent, 1-methyl imidazole (NMI) as an accelerator and glycerin was studied. The method to define gel content and Origm software version 8.6 was used to survey the curing process. Results showed that the curing rate and degree of crosslink of the epoxy resin were affected by contents and size of BC. Il was found that the degree of crosslink and curing rate decreased with the rise of BC size and BC contents.
Keywords. Epoxy resin, bacterial cellulose, curing 1. MO DAU
Can day, vi?c dua mgt lugng vi sgi xenlulo dang micro va nano phu hgp vao vat lieu polyme compozit da lam tang mgt sd tinh chat ca hgc ctia vat li?u ddng thai md ra nhieu ITnh vuc ung dung mdi cho loai vat li$u nay so vdi cac vat lieu ciing lo^i vdi sgl xenlulo thdng thudng [1].
Vi sgi xenlulo hinh thanh do vi khuan (Bacterial cellulose - BC) dugc tao ra nhd qua trinh sinh tong hgp xenlulo bang cac loai vi sinh vat khac nhau, la loai polyme sinh hgc cd nhieu ung dung khac nhau do nhung dac tinh quy bau duy nhat chi nd mdi cd nhu: ham lugng tinh thg cao (len den hon 90%), do ben CO hgc cao, ciu triic mang ludi chSng chit, do tinh khi^t cao,... [1,2].
Hien nay tren the gidi da cd mdt so cdng trinh nghien cuu dugc cdng bo lien quan den viec phan tan, ehe tao va tinh chat ciia compozit cd mat BG vdi cac nhn polyme khac nhu polyuretan [3], xenlulo axetat butylrat [4], nhua acrylic nhiet dn [5], nhua phenolic [6], poly (etylen oxit) [7], tinh bdt da dugc deo hda [8, 9], polylactic axit [10] ... va g^n day la cdng trinh nghien ciiu cua Toru Fuji va cac cdng sir [11]. Trong cong trinh nay da su dung BC da nang cao linli chit nhua nln epoxy bien tinh cao su Idng trong vat ti^u compozit gia cudng vai cacbon nhung chua khao sat anh hudng ciia BC den qua trinh ddng
ran nh^ra epoxy. Chinh vi vay, cdng trinh nay da di sau nghien cuu cti-u van de neu tren.
2. THUC NGHIEM 2.1.H6achat
Nh\ra epoxy epikote 828 (Shell Chemicals) co ham lugng nhdm epoxy 22,63 %, dd nhdt 12-14 Pa.s (25 °C). _
Vi sgi xenlulo dugc ch6 tao tu thach dira cita ca sd san xuat Anh Khoa (Ben Tre).
Anhydrit 4-metylhexahydrophtalic (Jiaxing Alpharm, Trung Qudc).
1-metylimldazol (BASF, Singapore).
2.2.Phiroiig phap phan tich
- Ham lugng phkn gel dugc xac djnh bSng each trich ly bang axeton trong bg Soxhlet vdi thdi gian 14-16 gid.
- Phan bd kich thudc vi sgi dugc xac djnh tren thiet bj HIROBA laser scattering j-Tticle size distribution analyzer LA-950 (My).
2.3. Phuffng phap xu- ly so lieu thurc n;.. hicn, Cac sd li?u thgc nghiem dugc xu ly hktig phSn
TCHH, T. 52(6), 2014
mim Origin phien ban 8.6. Cac dd thj anh hudng ciia cac yeu td khao sat din miic dg ddng ran ctia nhua epoxy dugc lay theo md hinh dudng Bolzman vdi phucmg trinh'tdng quat:
Y = A2 + (ArA2)/[l+exp(x-Xo)/dx].
3. KET QUA VA THAO LUAN
3.L Anh huomg ciia kich thudc BC den qua trinh ddng r5n he ER/MHHPA
De khao sat anh hudng cua kich thudc BC den
va Minh Buc va cdng su qua trinh ddng r5n he ER/MHHPA da su dung 2 loai BC (BCl va BC2) vdi ham lugng 0,2 % BC (tinh theo khoi lugng nhua epoxy). Phan bd kich diudc vi sgi BC dugc trinh bay tren hinh 1 va 2.
Qua trinh ddng ran nhira epoxy bSng chSt ddng rin MHHPA vdi ty le mol ER/MHHPA = 1/0,8 dugc thuc hien d nhiet dd 100 "C khi cd mat 1,5 % xiic tac 1-metylimidazol (1-NMl) va 1,5 % glyxerln (tinh theo khoi lugng he ER/MHHPA).
Anh hudng cua sir phan bd kich thudc BC din muc do ddng ran va van tdc ddng r4n ctia nh^ra epoxy dugc trinh bay tren hinh 3 va 4.
Hinh 1: Gian do phan bo kich thudc BCl
Kich thudc trung binh ciia vi sgi: 765,40 jim; dai phan b6 kich thudc vi sgi tir khoang 10 nm d^n gdn 3000 nm
as-*
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D10C' 1000 -iOOO 1000 1000 30C
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Hinh 2' Gian dd phan bd kich thudc BC2
Kich thudc trung binh cua vi sgr 1,30 \im; dai phan bo kich thudc vi sgi trong khoang 0,1 \im den 70 pm Ket qua cho thiy khi cd mat BC mijc do ddng
ran cua nhira epoxy thay ddi khdng dang ke, sau khoang 40 phiit qua trinh ddng ran xay ra gan nhu hoan toan. Qua trinh ddng rdn nhua epoxy cd mat BC Cling mang tinh tu xiic tac tuong tu nhu khi khdng cd BC [12] va van tdc ddng r4n bi giam nhe so vdi nhua epoxy nguyen thi, kich thudc BC cang Idn v^n tdc ddng rdn cang giam (hinh 4).
3.2. Anh hirdng cua ham Ivtfng BC den qua trinh ddng ran nhtra epoxy
De khao sat anh hudng cua ham lugng BC2 den qua trinh ddng r5n he ER/MHHPA = 1/0,8 (tinh theo ty le mol) da tien hanh phan ung ddng ran h? tren d 100 "C khi cd mat 1,5 % xiic tac NMI va 1,5 % glyxerin (tinh theo khdi lugng he ER/MHHPA).
TCHH, T. 52(6), 2014
Ham lugng BC2 thay ddi tir 0; 0,1; 0,2 va 0,3 % (tinh theo khdi lugng nhua epoxy).
Hmh 3: Anh hudng ctia su phan bo kich thudc BC dSn miic dd ddng r4n nh\ra epoxy vdi
0,2%BC2(1);0,2%BC1(2);
nhua epoxy nguySn the (3)
Nghiin cuu chi tgo vgt li "^ • 0,1 % BC. Vdi ham lugng 0,3 % BC, van -jc ddn^g rin giam khd nhilu so vdi nh\ra epox> ..^lyen the.
Di6u nay cd the la do s\t can trd khdng gian ciia BC Iam cac phan tii hoat d^ng di chuyin khd khan hon va ket qud Id phan umg ddng rdn hi han ehe. Hdm lugng BC cang cao, cdn trd khdng gian cdng Idn va do dd vSn tdc ddng rdn cang gidm. Do cd chira nhieu nhdm hydroxyl trong thanh phan cua BC, le ra BC xuc tiSn phdn litig ddng i ^ nhga epoxy nhung th\rc t l l^ii lam ch§m phan ung ddng ran. Nguyen nhan cd the Id do cd s^r tao thdnh lien ket hydro giua BC vdi nhdm hydroxyl trong mach nhua epoxy lam gidm cac phan tiir boat ddng trong nhyra epoxy.
Tbbi gian. pbfit
Hinh 4: Anh hudng ctia sir phan bd kich thudc BC den v|n tdc ddng ran nhua epoxy vdi
0,2 % BC2 (1); 0,2 % BCl (2);
nhua epoxy nguyen the (3) Ket qud dugc the hien tren hinh 5 va 6.
Cac sd lieu nhan dugc cho thay khi ham lugng BC thay ddi tir 0 den 0,3 %, mtjc do ddng rdn cita nhua theo thdi gian thay ddi khdng dang kl. Sau khoang 40 phiit, muc do ddng rin dat tren 90 %.
Van toe ddng ran ciia he nhua epoxy giam khi cd m§t BC va khi ham lugng BC cang tang, van tdc ddng ran cang gidm, tuy nhien d ham lugng 0,2 % BC mdc dg gidm khdng dang kl so vdi ham lugng
Thdi gian, phut
Hinh 5: Anh hudng cua hdm lugng BC din miic dO ddng ran nhua epoxy vdi
0,1 % BC (1); 0,2 % BC (2); 0,3 % BC (3);
nhua epoxy nguyen the (4)
Thdi gian, phiit Hinh 6: Anh hudng ciia ham lugng B j
ddng rin nh\ra epoxy vdi 0,1 % BC (1).
(2); 0,3 % BC (3); nhua epoxy ngu>
n van toe
%BC tr.e.'^)
TCHH, T. 52(6), 2014 4. KET LUAN
Da tiln hanh khao sat anh hudng ctia sir phan bd kich thudc BC din qua trinh ddng ran he ER/MHHPA va nhan thiy khi kich thudc BC cang Idn, cang can trd phan trng ddng rin va kit qud la cang lam gidm miic do ddng ran va van tdc phan ting ddng ran.
Da tiln hanh khdo dnh hudng cua ham lugng BC den qud trinh ddng rin he ER/MHHPA va nhan thiy ham lugng BC cang cao, mire do ddng ran ciing nhu van tdc ddng rin cang giam.
Ltrf cam on. Cdc tdc gid trdn trgng cdm an Phdng thi nghiem trgng diem Vgt lieu Polyme va Compozit - Truang Bgi hgc Bdch khoa Hd Ngi vd di tdi
"Ndng cao tinh chdt ca hoc cua vgt lieu compozit nin nhua nhiet ran (epoxy, polyeste khdng no PEKN) cd mat vi sgi xenlulo. md sd PTNTD. 2011- C/01 dd hd trg vi ca sa vdt chdt vd tdi trg kinh phi di thuc hien nghiin cuu ndy.
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Lien he: Vu Minh Due
Trung tam Nghien ciiu vat lieu polyme Trudng Bach khoa Ha Ngi
So 1, Dai Cd Viet, Hai Bd Trung, Ha Ngi E-mail: [email protected] Dien thoai: 0945467576.
