Tgp chi Hoa hgc,
T. 48(6), Tr. 758 - 762, 2010
NGHEN CQU CHE TAO VAT LIEU POLYME COMPOZIT TREN CO S6 NHL/A NEN POLYESTE KHONG NO VA SILICAFUM
PHAN I - CAU TRUC VA T I N H CHAT VAT LIEU POLYME COMPOZIT TREN NEN NHUA POLYESTE KHONG NO VA SILICAFUM KHI CHUA CO CHAT LIEN KET
De'nTda sogn 11-8-2010
TRINH MINH DAT', BUI CHUONG', BACH TRQNG PHUC',
NGUYEN THI P H U O N G NHUNG'
'Trung tdm Vdt lieu hdu ca vd Hda phdm xdy dung, Vien Vdt lieu xdy dung 'Trung tdm Nghien cUu Vdt lieu Polyme, Trudng Dgi hgc Bdch Khoa Hd Ndi
ABSTRACT
Ortho unsaturated polyester/silieafume composite were prepared by high rate mixing with unchangeable temperature, then using ultrasound wave and vacuum to eliminate bubbles.
Dispersion of the silieafume was characterized by viscosity, SEM and TGA. The results showed that viscosity of composition and dispersion level of silieafume depend on time and speed of mixing. The best mechanical properties were obtained at silieafume content 1.5 wt%.
I - MO DAU
Silicafum la oxit silic sieu min d dang vd dinh hinh thu hdi tQ khdi Id che tao thep silic hoac ferosilic. Silicafum da dugc sQ dyng nhilu trong cdng nghiep san xudt son, nhya bdi le chung dugc coi la chdt dgn gia cudng cd khd nang lam tang do cQng, bin cdo xude, mai mdn,... [1]. Tuy nhien, de dat dugc nhQng tfnh chdt mong mud'n thi khd khan ldn nhdt la lam sao phan tdn ddng nhat silicafum trong nin nhya do di Mc giQa cdc hat ldn ludn cd khuynh hudng tao thanh cac tap hgp hat. De tang kha nang phan tan thi khuay trgn d td'c dd cao la mgt phuang phdp thdng dyng nhdt, ngodi ra cd thi su dyng chdt lien kit silan de tao cho b l mat hat silicafum tilp xuc ldn ban ldm gia tang lien kit giua hat dgn vd nen nhua [2].
Trong cdng trinh nghien cQu nay, da tap trang vdo nghien cQu qui trinh che tao vd cdc dac tfnh cua hdn hap nhua octo polyeste khdng
no vd silicafum khi chua cd chdt lien kit.
II - THUC NGHIEM 1. Nguyen lieu
- Nhua octo polyeste khdng no 2508 PT-WV cua Han Qud'c cd chi so axit 14 mg KOH/g, do nhdt (20°C) 260 cP.
- Chdt xuc tac metyl etyl keton peroxyt (MEKP) cua Hdn Qud'c.
- Chdt xuc tiln octoat coban 10% cua Nhat Bdn.
- Silicafum dang nen cua Trang Qude co phan bd kfch thudc hat trinh bdy tren hinh 1.
2. Phuong phap thuc nghiem
- Qui trinh c h i tao: vQa cho silicafum vdo vQa khua'y M tQ cho din khi bgt phan tan hit trong nhua, tilp dd khudy d td'c do cao cd dn dinh nhiet, sau khodng thdi gian xdc dinh mang
di sieu am. Sau khi cho chdt xuc tac vdo thi khudy diu, hut chan khdng vd cudi cung mang di dd mdu tren khudn Teflon phuc vu xac dinh cac tfnh chdt cua vat lieu.
- Phan bd kfch thudc hat duac xdc dinh tren mdy LS 320-COULTER cua Hoa Ky vdi dai do tQ (0,04 ^ 2.000) ^m.
- Do nhdt dugc xdc dinh theo tieu chuan DIN 53018 do tren nhdt ke Broockfield dang RVT cua Hoa Ky.
- Anh SEM cua vat lieu dugc chup tren may hien vi dien tQ quit Jeol JSM 6360 LV (Nhat
Ban).
- Dd bin keo xdc dinh theo tieu chuan ISO 527-1993, do tren may INSTRON 3382 (My).
- Dd bin udn xdc dinh theo tieu chuan ISO 178-1993, do tren mdy INSTRON 3382 (My).
- Dd bin nen xac dinh theo tieu chuan ISO 604-1993, do tren mdy INSTRON 3382 (My).
- Do mdi mdn xdc dinh theo tieu chudn ISO 9352-1995 do tren may Taber model 519-1 (Anh), banh mdi CSIO, chu ky 1.000 vdng.
- Phan tfch nhiet khdi lugng (TGA, DSC) tren may STA 409 PC/PG cua hang NETZSCH.
Differential Volume
20 ao ParticlR Diameter {\iu\)
100 200 400
Hinh 1: Phan bd kich thudc hat cua silicafum
III - KET QUA VA THAO LUAN 1. Anh hudng cua che do cong nghe
Silicafum cd kfch thudc hat tQ 0,1 -^ 0,2 pm, dien tfch be mat rieng (BET) 20 m'/g va b l mat phang nhdn khdng xdp, dilu nay cd thi kfch boat ldm gia tang tuang tdc vat ly giua chung vd nin nhua polyme. Bl mat silicafum tdn tai cdc nhdm silanol va siloxan. Cac nhdm silanol tao lien kit hidro vdi nhau hinh thdnh cau tnic tap hgp hat nhu sau:
Cdc lien kit nay keo giu cae hat silica rieng
le kit tu lai cung vdi nhau vd cdu tnic tap hgp dd duy tri khdng thay ddi tham chf dudi cdc dilu kien khudy trdn tdt nhat nlu nhu khdng cd su tuang tdc manh giua silica vd nin nhya [3].
Kit qua khdo sat vl thdi gian vd td'c dd khudy cho thdy, d thdi gian khuay 2 gid vd td'c do khudy 1.000 vdng/phut, polyme chua tham thdu hit vdo trong hat dgn (0,5 PKL so vdi nhya), cdc cdu tnic tap hgp hau nhu giQ nguyen, khdng bi phan tdch. Sau 6 gid khuay d td'c do 4.000 vdng/phQt da cd thi phan tach cdu tnic tap hgp hat va cdc tap hgp dugc phan chia phan bd diu hgn trong nin polyme. Kit qua do do nhdt da chi ra rdng, do nhdt cua hdn hap phu thugc vdo thdi gian, tdc do khuay vd tang len hai ldn.
anh SEM (hinh 2) cho thdy hat silicafum da phan bd ddng diu han, cac tap hgfp hat nhd ban nhilu so vdi khi khudy d td'c do thap trong thdi gian ngdn.
Nhu vay, thdi gian khudy dai da lam tang dien tfch tilp xue cdc hat silicafum vdi nhua nen
va td'c do khuay ldn da ngan can vd phan tdch cac cdu tnic hat kit ty. Dieu nay cung thi hien ro khi do ben keo, do bin nen, do ben udn, do bin va dap deu tang vd do mai mdn gidm xud'ng.
6 dilu kien khudy td'c do 4.000 vdng/phut trong 6 gid, khi tang hdm lucmg silicafum (0,5 de'n 2,5) PKL thi do nhdt cua hdn hgp tang tuye'n tfnh theo ham lugng dgn (hinh 3).
(a) (b) Hinh 2: Anh SEM cua mdu vdi thdi gian vd td'c do idiudy khde nhau
(a) 2.000 vdng /phut trong 2 gid; (b) 4.000 vdng/phut trong 6 gid
Q.
o
<o- Q
0 0,25 0,5 1 1,5 2 2,5 Ham lugng silicafum, PKL
Hinh 3: Su thay ddi do nhdt cua hdn hgp nhya theo hdm lugng silicafum
TQ hinh 3 cho thdy, khi cd mat silicafum chi vdi mgt lugng rdt nhd (0,25 PKL) do nhdt cua hdn hgp cung da tang gdn gdp ddi. Sy gia tang dd nhdt Id do trong qud trinh chuyen dgng cdc hat hoac tap hgp hat tragi len nhau ldm tang Mc ma sat ngi, vi t h i khi tang ham lugfng silicafum thi do nhdt cua hdn hgp cung tang len.
2. Cac dac trung cua vat lieu polyme compozit gia cudng silicafum khi chua co chat lien ket
Cdc mdu compozit dugc ky hieu nhu sau:
- SO: mdu trd'ng.
- S0,5: mdu chQa 0,5 PKL silicafum.
- Sl,5: mdu chQa 1,5 PKL silicafum.
- S2,5: mdu chQa 2,5 PKL silicafum.
Bang 1 trinh bay cdc tfnh chat ca hgc cua 4 mdu tren.
Sd lieu bdng 1 cho thdy, chi them vdi mgt lugng rat nhd silicafum trong dilu kien khudy trgn 4.000 vdng/phut trong 6 gid thi hdu hit cac tfnh chat ca hgc diu tang. Sy tang nay la do compozit chQa silicafum da cd sy phan tan vd sy dfnh kit b l mat tdt, vi t h i khi tac dung Qng suat thi Mc tac dyng chuyen din cdc hat silicafum thdng qua lien kit pha vd cdc hat silicafum nay trd thdnh tdc nhan nhan ting suat dd. Tfnh chdt ca hoc tdi tm xuat hien d ti le silicafum Id 1,5
PKL vd d ham Mgng cao hon thi tfnh chat ca hgc giam xud'ng. Dilu nay xdy ra la do sy phan bd cua hat lam gia tang xu hudng kit ty cac hat d mQc do cao ban.
Anh SEM (hinh 4) chi ra rdng, khi khdng cd
silicafum thi bl mat bi be gay cua mdu phdng, nhdn khdng dong diu va tdn tai nhieu Id rdng rat rd net (hinh 4a). Tuy nhien, khi cd mat silicafum, b l mat bi be gay cua mdu da thay ddi hoan toan, giam cdc Id rdng (hinh 4b, 4c).
Bdng 1: Cdc tfnh chdt ca hgc cua vat lieu polyme compozit gia cudng bdng silicafum
Mdu SO S0,5 Sl,5 S2,5
Dd bin keo, ' MPa
42,7 43,1 45,5 39,5
Do gian ddi khi dot, %
4,43 4,68 5,84 4,40
Dd bin nen, ' MPa
91,9 92,2 100,2
87,7
Dd bin udn, ' MPa
81,7 82,0 88,6 77,8
Do mdi mdn, mg/1000 vdng
60,6 58,6 54,0 56,5
(a) (b) (c) Hinh 4: Anh SEM cua vat lieu polyme compozit vdi hdm lugfng silicafum khde nhau
(a) 0 PKL silicafum; (b) 1,5 PKL silicafum; (c) 2,5 PKL silicafum
™
fa to
3Q
to 1%
— — TC OSC
I X y.C 7CG
f
• /
v/
V
.-^™
^-^
VS:
osc;
10
:„.,
05
WJ
DO
£ ^ ,%» lB-":ia. Wy'£r' (KQ..».i.J. SST
/ • ^ N n
-:o -ji. &;c
(a) (b) Hinh 5: TGA va DSC cua vat lieu polyme compozit cd va khdng cd silicafum
(a) mdu khdng cd silicafum; (b) mdu chQa 1,5 PKL silicafum
Sy cd mat ciia silicafum phan tan dong diu lien kit vdi nin, vi t h i Qng xu nhiet tren hinh 5 trong nin nhua polyeste khdng no lam gia tang cho thay nhiet do hda thuy tinh (Tg) cua mdu cd dang k l dien tfch tilp xuc bl mat va gia tang silicafum (hinh 5b) cao ban mdu trdng (hinh
5 a). Dac biet la mdu chQa silicafum cd do bin nhiet ldn ban mdu trdng, tai nhiet do 520°C thi mdu trd'ng bi phan buy 91,13% cdn mdu cd silicafum bi phan buy thdp ban 90,65%.
IV - KET LUAN
Khd nang phan tdn silicafum trong nin nhya polyeste khdng no tdt nhdt vdi td'c do khuay 4.000 vdng/phut trong 6 gid. Viec dua silicafum chi vdi lucmg rat nhd da lam tang dang ke do nhdt cua hdn hgfp nhua va do nhdt tang Myln tfnh khi tang hang lugng silicaMm. Cdc tfnh chdt eg hgc dat dugc tdi tm d ham lugfng silicafum la 1,5 PKL. Tren eg sd phan tfch bdng dnh SEM vd DSC chi ra rdng nhiet do hda thuy tinh cua mdu cd silicafum cao ban mdu khdng
cd silicafum va d nhiet do 520°C thi mdu khdng cd chat gia cudng bi phan buy (91,13%) ldn han mdu cd chat gia cudng (90,65%).
T A I LIEU THAM K H A O
1. Herbert Barthel, Michael Dreyer, Torsten Gottschalk-Gaudig, Victor Litvinov and Ekaterina Nikitina. Macromol. Symp, Vol.
187, 573 - 584 (2002).
2. C. Lekakou, I. Kontodimopoulos, A.K.
Muragesh, Y. L. Chen, D.A. lesson, J. F.
Watts, P. A. Smith. Polymer Engineering, and Science, Vol. 48, 216 - 222 (2008).
3. Hua Zou, Shmshan Wu, and Jia Shen.
Chemical Review, Vol. 108(9), 3893 - 3957 (2008).
Lien he: Bach Trong Phuc
Trang tam Nghien cQu vat lieu polyme Trudng Dai hgc Bach khoa Ha Ngi S o l , Dai Co Viet, HaNgi.
Email: [email protected].
