Nghien ciru. Phdt triin yg Ung dun? Cong nehe Vdt lieu (KC.02/06-10)- Ha Noi 27/11/2009<br />
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D A N H GIA A N H HUONG CUA PHUONG PHAP XU" L Y DEN T I N H CHAT SOI<br />
NUA DUNG DE CHE TAO V A T L I E U P O L Y M E PHAN HUY SINH HOC<br />
<br />
Tran VInh Dieu, Doan Thi Yen Oanh, Nguyln Pham Duy Linh, Le Due Luong<br />
Trung tam Nghien cuu Vat lieu Polyme, Truang DHBK Ha Noi<br />
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Abstract. Neohouzeaua fibers were prepared by mechanical method. Its composition<br />
and morphology of fibers were studied. The analytical result shown most of hemi-<br />
cellulose and lignin were removed. FTIR spectroscopy shows that strong sharp peak in<br />
the untreated bamboo spectrum at about 1736 cm' corresponding to carbonyl group<br />
1<br />
<br />
<br />
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(C=0), but this peak disappeared in alkaline treated bamboo spectrum. Bamboo fiber<br />
reinforced polylactic acid composites have been prepared by 40% fiber contents. The<br />
mechanical properties of composite were also tested.<br />
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I. GlOl THIEU<br />
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Ngay nay vat lieu polyme phan huy sinh hoc ngay cang dugc nhieu nha khoa hoc quan<br />
tam nghien curu vi chung khong gay ra tac ddng xau vdi moi truang sinh thai. Tuy nhien, hau<br />
het cac vat lieu polyme phan huy sinh hoc dugc che tao tu nhua nen va chat gia cudng cd kha<br />
nang phan huy sinh hoc thudng cd gia thanh dat hon vat lieu plastic truyen thong. Trong<br />
nhung nam gan day, nguon sgi tu nhien da dugc nhieu nha khoa hoc chu y den do cay cho sgi<br />
phat trien nhanh va cd kha nang tai tao. Tre nua cd do ben rieng ldn, nhat la theo chieu doc<br />
sgi va ti trong nhd nen con dugc goi la "sgi thuy tinh tu nhien" [1-3]. Nhung tren thuc te viec<br />
sir dung sgi tre nua lam vat lieu gia cudng van con gap kho khan nhu dd hut am ldn, lien ket<br />
sgi nhua phu thudc nhieu vao tinh chat be mat sgi...[4,5,7,8]. Chinh vi vay, viec che tao sgi,<br />
bien tinh sgi va irng dung lam chat gia cudng cho vat lieu polyme phan huy sinh hoc la nhung<br />
hudng nghien cuu dang dugc quan tam. De khac phuc nhung nhugc diem neu tren va tang<br />
cudng kha nang lien ket giua nhua nen va sgi gia cudng, da tien hanh danh gia anh hudng ciia<br />
phuang phap xir ly den tinh chat soi nua dung d l chi tao vat lieu polyme phan huy sinh hoc.<br />
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H. THUC NGHIEM<br />
<br />
1. Nguyen lieu<br />
- Nhua polylactic axit ciia hang Nature Works @ PLLA polymer 2002 D (My), san pham<br />
d dang hat cua Nature Works LLC, ty trong 1,24 g/cm , nhiet dd ndng chay 160-180°C<br />
3<br />
<br />
<br />
<br />
- Nua tuoi ciia tinh Thanh Hda, cd ham lugng phan tro 2,61%;<br />
- NaOH ky thuat (Trung Qudc).<br />
<br />
2. Phuong phap gia cong<br />
a) Phirong phdp che tao soi nua<br />
Nua tuoi dugc cat va che thanh thanh dai, dugc can tren may can hai true va cao tach cd<br />
ky hieu SNO. Sgi xir ly bang dung djch NaOH 0,1 N , trong 72 gid d nhiet dd phong cd ky hieu<br />
SN1 [5, 6]; sgi nua xir ly bang dung dich NaOH 1 N, d nhiet dd 90°C trong 2 gid cd ky hieu<br />
SN2 va soi nua tach nd bang hoi nude cd ky hieu SN3 [7]. Sgi nira sau khi xir ly trong dung<br />
dich NaOH dugc rua sach bang nude, phoi va say kho, sau dd ep thanh cac tam mat de che<br />
tao vat lieu compozit.<br />
b) Phirong phdp che tao vdt lieu compozit<br />
Vat lieu compozit dugc ep ndng trong khudn tren may ep Gotech 30 tan (Dai Loan) d<br />
nhiet do 170°C, ap lire 50 kG/cm trong 25 phut.<br />
2<br />
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67<br />
Nshien cicu. Phdt trien va Ung duns Cons nshe Vdt lieu iKC.02/06-10)- Ha Noi 27/11/2009<br />
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3. Cac phirong phap xac dinh tfnh chat<br />
a) Tinh chdt cua soi<br />
- Dp ben keo ciia soi nua xac dinh tren may keo soi LLoyd, 0,5 K N (Anh), tdc do kdo 5<br />
mm/phiit.<br />
- Do bin bam dinh ciia soi va nhua xac djnh tren may LLoyd 0,5 K N (Anh), tdc dd keo 2<br />
mm/phut.<br />
- Duong kinh soi xac dinh bang kinh hiln vi quang hoc vdi dd phong dai 1000 lan.<br />
- Thanh phan hoa hoc b i mat soi nghien cuu thong qua phan tich phd hong ngoai IR tren<br />
may Tensor 27 ciia hang Bruker (My) vdi dd phan giai 4 cm" .<br />
b) Tinh chdt ciia vdt lieu compozit<br />
- Do bin keo xac dinh theo tieu chuin ISO 527-1 tren may INSTRON 5582-100 K N<br />
(My). Tdc dd keo 5 mm/phut d 25°C, dd i m 75%.<br />
- Dd ben uon xac dinh theo tieu chuin ISO 178-1993 tren may INSTRON 5582-100 K N<br />
(My). Tdc do udn 5 mm/phiit d 25°C, do i m 75%.<br />
- Dd bin va dap xac dinh theo tieu chuin ISO 179-1993 tren may Radmanna ITR-2000<br />
(Uc).<br />
- Cau tnic hinh thai ciia soi va vat lieu xac dinh bang phuong phap chup anh tren kinh<br />
hien vi dien tu quet (SEM) JEOL JMS 6360 L V (Nhat Ban).<br />
<br />
in - KET QUA VA THAO LUAN<br />
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1. Tinh chat cua soi nira<br />
a) Xac dinh ham dm ciia soi nira<br />
Ham am ciia soi nua che tao theo cac phuong phap neu tren cd ky hieu SNO, SNl, SN2 va<br />
SN3 trinh bay d bang 1.<br />
Ket qua d bang 1 cho thay, loai soi SNl sau khi xir ly bang dung dich kiem 0,1N, 72 gid d<br />
nhiet do phong cd dp hut am cao nhat. Cd the sau khi xir ly da loai bdt mot phan tap chit tren<br />
be mat soi va sd lugng nhdm - O H tren be mat cao hon so vdi ba loai soi neu tren nen kha<br />
nang hut am ldn hon.<br />
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Bdng 1. Ham dm ciia soi nira tnroc va sau khi xir ly kiim<br />
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Loai spi Ham am, %<br />
SNO 11,1181<br />
SNl 18,3964<br />
SN2 14,5297<br />
SN3 11,8947<br />
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b) Xac dinh dp ben keo ciia soi<br />
Da khao sat bdn loai spi nira SNO, SNl, SN2 va SN3 moi loai 50 mau do. K i t qua trinh<br />
bay tren hinh 1. Tir hinh 1 nhan thay, dp ben ciia spi SNl va SN2 ldn hon loai SNO lan luot la<br />
30,74% va 18,37%. Dd la sau khi spi dupe xu ly kiem thi mot phin lignin va hemixenlulo bi<br />
tach ra, do dd cac spi de dang dinh hudng theo hudng keo va su phan bd tai trong tron^ bd soi<br />
tdt hon nen dp ben keo ciia loai spi SNl ldn hon loai chua dugc xir ly kiim. Sgi SN3 cd do<br />
ben keo thap hon so vdi SNO, cd the do dieu kien tach sgi chua dat tdi uu. Tir ket qua nay da<br />
lira chon loai SNO va SNl de so sanh va lam cac thi nghiem tiep theo.<br />
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68<br />
Nghien a'ai. Phdt trien va Ung dune Cone nehe Vdt lieu (KC.02/06-10)- Ha Noi 27/11/2009<br />
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393,78<br />
400 356,51<br />
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301,191 283,791<br />
2<br />
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300<br />
o<br />
a<br />
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Q 200<br />
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inn SNO SNl SN2 SN3<br />
Loai sod nua<br />
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Hinh 1. Dp ben keo trung binh cua 4 loai soi nua<br />
Xac suat tich tu do ben keo cua hai loai sgi nua SNO va SNl dugc trinh bay tren hinh 2.<br />
Tu hinh 2 nhan thay, ddi vdi loai sgi SNO, dd ben keo tap trung trong khoang tir 100 den 300<br />
MPa cdn ddi vdi sgi S N l , do ben keo phan bd trong khoang rdng hern tir 100 den 400 MPa.<br />
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<br />
100.00<br />
90.00<br />
80.00<br />
70.00<br />
60.00<br />
0 50.00 • Sgi chua xir ly<br />
s<br />
a 40.00 • S g i xir ly hda<br />
(J 30.00<br />
X 20.00<br />
10.00 3 t<br />
0.00<br />
200 400 600 800 1000 1200<br />
Dd ben keo sgi, MPa<br />
Hinh 2. Xac sudt tich tu dp ben keo ciia soi SNO va SNl<br />
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c) Cau true be mat soi nua trudc vd sau khi xir ly kiem<br />
Be mat sgi nua trudc va sau khi xir ly kiem trinh bay tren hinh 3. Tir hinh 3 cho thay, sgi<br />
nua loai SNl sau khi xu ly kiem cd be mat ddng nhat hon so vdi cac loai con lai chimg to<br />
trong qua trinh xu ly da loai bd dugc mot phan ldn lignin va hemixenlulo va cac tap chat khac<br />
tren bd mat sgi do dd lam thay ddi dang ke khong nhirng cau true be mat sgi ma con ca thanh<br />
phin hoa hoc cua sgi. Ket qua nay cd the lam sgi cd the tham nhua tdt hon va tang kha nang<br />
bam dinh giua sgi va nhua.<br />
Sir thay ddi thanh phan be mat sgi nua dugc the hien rat ro qua phan tich phd hong ngoai. Ket<br />
qua phan tich dugc trinh bay d hinh 4. Tir hinh 4 nhan thay, sir ton tai dinh hip thu 1736 cm" 1<br />
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ro net tren phd hong ngoai ciia sgi nua chua xir ly, dinh hip thu nay dac trung cho lien k i t<br />
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69<br />
Nnhien cicu, Phdt trien va Lfne duns Cons nshe Vdt lieu (KC.02/06-10)- Ha Noi 27/11/2009<br />
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C=0 ciia hemixenlulo va lignin nhung no da khong xuat hien trong pho hip thu ciia soi da xir<br />
ly SNl.<br />
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d) Do bam dinh giua nhua polylactic axit (PLA) va soi nua<br />
Do bam dinh giua soi nira va nhua PLA the hien a do ben trupt trinh bay a bang 2.<br />
Ket qua bang 2 cho thay, loai soi SNl cd do bam dinh tdt hem so vdi cac loai spi con lai va<br />
cao hem 57,3% so vdi SNO.<br />
2. Khao sat anh huong cua ty le soi/nhua den tinh chat cua vat lieu compozit<br />
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Soi nira tdch no hoi nude Soi nira xir ly kiim ndng IN, 90°C, 2 gid<br />
Hinh 3. Anh SEM cua be mat soi nira trudc vd sau khi xir ly kiim<br />
Da tien hanh khao sat anh hudng ciia ty le giua spi/nhua din tinh chit ciia vat lieu<br />
compozit, ham lupng mat nira thay ddi tir 30 din 40% khdi lupng. Dp bin keo, udn va dp va<br />
dap ciia cac mau vat lieu trinh bay tren hinh 5, 6 va 7.<br />
<br />
XXX T790 StOD ?za ax,<br />
\f~\i SoTnCractaiaxCtK I ft<br />
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>c=o<br />
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1!<br />
m 8 s<br />
Jcor r? 2MO 32V><br />
Hinh 4. Phd IR cua soi nira SNO vd SNl<br />
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70<br />
Nghien cim. Phdt thin va ting dune Cone nehe Vdt lieu (KC.02/06-10)- Ha Noi 27/11/2009<br />
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Tir cac hinh 5 va 6 cho thay, khi tang ham luong soi nira thi do ben ciia vat lieu compozit<br />
tang va dat gia tri cao nhat d 40%. Dd cd t h i la do ham luong mat nua tang lam kha nang tiep<br />
nhan img suat ndi cua vat lieu tang theo. Nhu vay, ve If thuylt con cd kha nang tang ham<br />
luong soi nira trong vat lieu compozit. Tuy nhien, d ham luong sgi nira tang den 50% thi vat<br />
lieu compozit nhan dugc khong ddng nhat do PLA cd tinh chay kem.<br />
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Bdng 2. Dp bam dinh trung binh giua soi nira va nhua PLA<br />
<br />
Loai Do ben trugt, MPa<br />
soi<br />
SNO 2,11<br />
SNl 3,32<br />
SN2 2,98<br />
SN3 3,07<br />
<br />
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25 23,70<br />
20,73 20,81<br />
19,60<br />
20-<br />
<br />
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15-<br />
o<br />
M<br />
c 10-<br />
X)<br />