KHOA HOC CbNG NGHE
MGHIEIV C i i u TilMH DIM DflMH KICH THIJOC CUA GA TRAIVI TRAIMG X U LY BOI OMDHEU
T ? Thj Phuong Hoa^
T6MTAT
Nghifen ctiu tinh dn dinh kich thudc ctia gd tram frdng xir ly bdi DMDHEU (dimetila dihydroxyt etylen urea) nong d6 khac nhau: 10%. 20%, 30%, 35%, 40% frong hai trudng hpp gd c6 qua xti ly lupc d nhi^t dd 70°C va khong xu ly lupc trudc khi tdm hoa chdt Khi xtr ly hoa chat vdi cac nong dp nhu frfen vdi 5.5% chat xtic tac MgClz da lam tang tinh on djnh kich thudc ctia gd tram frang; dp tang khdi lupng dat tir 9,85% din 26.24%. chiing to hoa chat da tham vao gd. Khi nong do tang tir 10%-35% lirong boa chat vao gd s€ tang, tuy nhifen sau do se hau nhu khong tang nua, frong khoang tir 35-40%. Khdi lupng thi tich kho kifit ctia mlu trudc xu ly va mdu ddi chting la 0,537 g/cm', con ctia mau xii ly dat tir 0.569 den 0.637 g/cm', tang tir 5,96%
din 19,85% so vdi trudc xti ly. Cac chi tifeu vl dn dinh kich thirdc: dp tang khdi lupng (dac trung cho lupng hoa chat vao go), dp tang khdi lupng thi tich ctia mau gd co xir ly lupc cao hon so voi mlu gd khong xOt ly lupc trudc khi tdm hoa chat D6 am gd ctia mdu ddi chting ldn hon eda mau xti ly khi lim giir frong cimg diiu ki$n moi trudng. 6 diiu ki6n moi truong vdi nhi?t dp (20t2)"C va dp am (65±3)% dp dm cua mau ddi chting la 12.37%, trong khi do do am ctia mau xtr ly dat 9.68% din 8,40%. Ty 1$ dan nd ldn nhdt theo chiiu tiep tuyen ctia mdu ddi chting la 6,81%, con chi ti6u nay cua mlu xir ly la 4,11% din 2,89%, tuong ting vdi h^
sd ASE dat 39,63% din 57,54 %. H? sd chdng dan nd ctia mlu khong qua xii ly lupc va qua xir ly lupc trudc khi xii ly hoa chat khong ch6nh l$ch nhilu khi so sanh d cimg dp tang khdi lupng.
Tir khda: Tram tiing, ti'nh on dinh kich thudc, DMDHEU.
I. DAT VAN D^
Chat lupng gd dupe xdc dinh bdi nhilu ddc tinh Uln quan d i n kha ndng su dung gd vd dupe ddnh gid bdi mtic dp phii hpp vdi timg muc dich str dting cu t h i , mpt sd ddc tinh chii yeu ddc trung cho chat lupng gd cd t h i k l d i n la tinh dn djnh kich thudc, dp b i n sinh hpc, dp b i n co hpc, kha ndng chdng chiu tia tii ngoai (tia UV), kha ndng chdng chju tdc ddng ctia mdi tiirdng frong diiu k i l n hi n h i l n (bao gdm tdc dpng ciia dm, mua, ndng, sinh vat) [4,5].
Thdnh phdn hda hpc chinh ciia gd gdm xenluloza, himixenluloza, linlin, frong phdn tiir ciia ca ba tiianh phdn ndy d i u chiia nhdm hydroxyl n i n gd cd kha ndng htit nha dm manh. Mdt khdc, gd cd cdu tao mao dan, trong gd cd cdc mao dan ldn (rupt t l bao vd khe hd giua cdc t l bdo) vd cdc vi mao dan trong vdch t l bdo. Nudc ttr do tdn tai frong cdc mao dan ldn vd sir thay ddi lupng nudc nay khdng lam tiiay ddi kich tiiudc gd. Nude thdm ndm frong vdch t l bdo vd loai nudc ndy anh hudng d i n mpi tinh chat gd, kich tiiudc gd tiiay ddi khi lirpng nudc ndy thay ddi.
Ndi tdm lai, khi dp am mdi trudng tiiay ddi dp dm gd tiiay ddi vd ddn d i n tiiay ddi kich tiiudc go. Tinh dn djnh kich tiiudc cua gd la chi tilu vat ly quan frpng d l ddnh gid chat lupng vd kha ndng sir dung gd. Do
Trudng D^ii hpc Lam nghifp
vgy mdt frong nhiing b i | n phdp ndng cao tinh dn djnh kich thudc ciia gd Id b i i n tinh hod hpc gd bdi mdt sd loai hod chdt khi phdn iing vdi gd sfi tao ra liln k i t ngang giua cdc nhdm OH vd nhdm chtic ciia hod chat xti ly, ddng thdi cd t h i tao ra mdng polyme d frong gd [4]. Trong nhirng ndm gdn ddy hod chat DMDHEU - mdt loai hod chdt ciia ngdnh d l t may dd dupc nhilu nudc nghiln ctiu thdnh cdng frong vile ndng cao tinh dn djnh kich thudc vd nhilu chi tilu chdt lupng gd nhu dp b i n sinh hpc, kha ndng chdng chju tdc ddng ciia mdi tnrdng frong diiu k i | n tti nhiln [4,5]. Khi DMDHEU dupe tam vdo gd dudi tdc ddng cua chat xtic tdc vd n h i | t dp, mdt phdn hda chdt tham gia phdn ling vdi thdnh phan hda hpc ciia gd tao liln k i t ngang, ddng thdi xdy ra phdn iing triing ngung (polime hda) ldm cho vdch t l bdo gd truong nd va t h i tich cua gd dat d i n miic ldn nhdt K i t qud la tao ra mang polime vd ldm cho gd khdng cd khd ndng quay frd lai kich thirdc ban ddu. Do dd tinh chdt ciia gd dupc cdi thiin.
DMDHEU cd khd ndng phdn iing vdi 2 nhdm hydroxyl gdn k l oxy vdi liln k i t ddi. Trong phan irng chinh, cac nhdm hydroxyl nay phan img vdi cdc nhdm hydroxyl khdc vd tao n i n cdc h l n k i t ete vd nude thodt ra (Krause va ddng tdc gid, 2003). 6 ddy, hda chdt tao liln k i t ngang vdi xenlulo cd t h i xay ra vdi nhdm N-metiiylol vd vdi nhdm hydroxyt d vj tri 4
NONG NGHIEP VA PHAT TRIEN NONG T H 6 N - KY 1 THANG 9/2011 91
KHOA HQC C Q N G NGHE vd 5. Tham chi chi ldm ndng nhe (d nhilt dp 70-80°C)
ciing dan din tao Uln kit ngang frong DMDHEU vd frong vai gid hda chat se frd nin khdng tan frong nude (Ashaari va ddng tdc gia, 1990). Trong khi xii ly gd bdi DMDHEU cd thi kem tiieo sir tao thanh fomandehyt do nhung phdn tti DMDHEU khdng
phan ting tao nin. Vi thi, dl phdn iing diln ra nhanh vd theo hudng mong mudn la tao liln kit ngang giiia DMDHEU vdi thdnh phdn hda hpc gd cdn phai sir dtmg chat xiic tac, xtic tac dirpe sti dtmg frong nghiln ctiu nay la MgCl2x6H20.
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Hinh 1. Mo hinh tuong tacgiCra DMDHEU voi
Bdi bdo trinh bdy kit qua nghiln ctiu ve tinh dn djnh kich thudc ciia gd fram frdng xii ly bdi hda chat DMDHEU, ddy la mpt phdn kit qua frong nghiln ciiu ndng cao chat lupng gd fram frdng bdng phuong phdp hiln tinh bdi DMDHEU [1, 2].
L VAT LIEU VA PHUDNG PHAP NGHIBV CUU
1. Vdt U|u nghiln ciiu
Vit lieu: Gd fram frdng (Canarium album Raeusch) 20 tudi, dupe khai thdc tai Chuong My, Ha Ndi; hda chat dimetyl dihydroxy etylen urea (DMDHEU), clorua magil, nude cat
Trong qud trinh nghiln ciiu da xdc djnh dupe ty ll hpp ly giiia chat xtic tac clorua magife vd hda chat DMDHEU, ty 11 cho hiiu qua xii ly cao dting frIn khia canh dd tdng khdi lupng gd xii ly Oirong hda chat vdo go va phan iing) la 5,5% khdi lupng chat xiic tdc so vdi khdi lupng hda chat DMDHEU.
Kit qua nghiln ciiu cho thay gd frdm frdng khi xii ly lupc cd dp thdm hod chat DMDHEU cao hon so vdi gd chua qua xii ly lupc [1, 2]. Do vdy frong nghiln ciru nay tinh dn djnh kich thudc gd frdm frdng xii ly bdi DMDHEU vdi cdc ndng dp khac nhau nhung cimg ty ll chat xiic tac so vdi hda chat DMDHEU dupe thue hiln vdi mau gd qua xu ly thuy nhilt Oupc) vd khdng qua xti ly thtiy nhilt
Thiitbi:hi dieu nhilt RW-3025G (Han Qudc) cd till diiu khiln nhi|t do tii -25°C din 100"C, tiiilt bj
Hinh 2. Cac phan irng giira DMDHEU vdi nhdm OH cua xenlulo, giira cac phan tu DMDHEU, tao fomandehyt, phan ung giira
DMDHEU \in nhdm NH
tam chdn khdng dp luc, tii say, cdn phdn tich, thilt bj do kich thudc.
2. Phuong phdp nghiln cuu
a. Thue nghiim tim hoi chit DMDHEU
Bd tri thue nghi|m don ylu td, ylu td thay ddi la ndng dp hda chat DMDHEU vdi cdc cap khdc nhau:
Yiu to dau rao.* Ndng dp hda chdt DMDHEU:
10, 20, 30, 35, 40%.
Mdu gd qua xu ly thtiy nhilt Oupc) frong 12 gid vd khdng qua xu ly thiiy nhilt ciing dupe tiln hanh xti ly hda chat sau dd xdc djnh tinh chat
Yiu to dau ra: Tinh dn djnh kich thudc ciia go:
dp tdng khdi lupng, khdi lupng thi tich, dp dm thdng bdng, ty ll dan nd, hi sd chdng dan nd.
Yiu in cd dinh. Qua trinh xir ly thiiy nhi^t Nhi?t dp xtr ly la 70°C, dp am go tiirdc khi xii ly 40%, tiidi gian xir ly 12 gid^
- Qua tiinh xti ly hda chat DMDHEU: Dp dm go trude khi tam -12%, thdi gian nit chdn khdng -30 phtit;
thdi gian duy tri dp Itrc 90 phtit; ty 11 chat xtic tdc - 5,5% khdi lupng so vdi hda chat DMDHEU, nhilt dO xtr ly nhilt -120°C, thdi gian xii ly nhilt sau tdm -12 gid.
Dung djch tam dupc chuan bj theo ndng dp da lua chpn, ty ll vl khdi lupng giira MgCla va DMDHEU (5,5%), dung mdi la nudc. Ba tiianh phdn nay dupc can theo ty ll dd chpn, cho vao ciing mpt 92 NONG NGHI|P VA PHAT TRIEN NONG THON - KY 1 THANG 9/2011
KHOA HOC C Q N G NGHE
thilt bj chiia va khuay diu, sau dd mdi dupe str dting d l tam. Dung djch tdm sau khi da chudn bj phai dupc sir dting ngay, khdng cho tiip xiie vdi mdi trudng cd nhilt dd cao (fr6n40°C).
Sd lupng mau thi nghilm cho cdc tinh chdt dupc xdc djnh theo cdc tilu chuan tuong iing. Kit qua xdc djnh dupe xii ly theo cdc chi tilu tiidng k l theo phdn mim Data analys frIn Excel.
Mau dupc chuan bj tir cdy sinh trudng binh tiiudng, khdng bj cut ngpn, khdng bj sdu binh. Mtic dich ciia nghiln ctiu ndy la nghiln oiu dnh hudng ciia xtr ly DMDHEU din tinh chat gd nin d cdc chi dp thtrc nghilm cdc mau phai dupc lira chpn vd phdn chia theo cdc chi dp, sao cho trude khi xtr ly cdc mdu cd cdu tao, tinh chdt cd mtic dp chinh lich nhd nhdt d tat ca cdc chi dp xii ly vd khdng xii ly. Vi thi, phuong phdp Idy mau xdc djnh tinh chdt gd dupc tiitrc hiln theo tilu chuan TOCT 16483.21-72 sira ddi ndm 1984 - "Gd - Phuong phip liy miu di xie dinh
tinh chit calygd sau qui trinh cdng nghi" [6]. Khdi lupng thi tich, dp tdng khdi lupng, dp am gd vd ty ll dan nd dupe xac djnh frIn ciing cdc mdu gd. Sd lupng chi dd xu ly hda chat Id 5, tiln hdnh frong tnrdng hpp mau gd qua ludc vd khdng qua lupc, nhu vdy cd 5 chi dp cho mdi trudng hpp vd cdc mau ddi chiing; tdng cdng can 11 chi dp thi nghilm.
Cic budc tiin hanh thue nghiim
Xtr ly thiiy nhilt: Vdi cac mau cdn xtr ly thiiy nhilt trude khi xOr ly hda chat, cho mau vdo b l diiu nhilt cho nudc cat vdo sao cho mau gd chim frong nudc, gia nhi|t cho din khi nhilt dp nude frong b l dat 70"C, xii ly d nhilt dp ndy frong thdi gian 12 gid.
Sau dd Idy mau gd ra, say d nhilt dp 45°C frong 48 gid.
Tdt cd cdc mau dd xu ly tiitiy nhilt khdng yixi ly tiiiiy nhi|t vd mdu ddi chiing dupc dua vdo tii say, tdng ddn nhi|t dd vd sdy d nhi|t do 103±2"C cho din khd ki|t, cdn khdi lupng vd do kich tiiudc mdu tiirdc xti ly vd mdu ddi chiing d frang tiidi khd k i | t
Luu gifr cdc mdu go frong diiu kiln phdng d nhilt dp (20±2)°C vd dp dm (65±3)% cho din khi dat dd dm khoang 12%.
Khi d^i dp dm 12% cdc mdu gd cdn xii ly hda chdt dupc tdm hda chdt vdi cdc ndng dp tiiong ting vdi cdc chi dd tiieo bd tri tiitrc nghi|m da niu frIn.
Cdc mdu gd ddi chting vd xu ly dupe say den frang thdi khd kilt, sau dd dupe luu giii frong diiu kiln mdi trudng vdi nhilt dd 20''C vd dp am mdi frudng ldn lupt tiiay ddi: 55, 65, 75, 92%. Trong mdi mdi trudng tuong iing vira niu cdc mau gd dupe lim giir cho din khi dat khdi lupng khdng ddi. Tiln hdnh cdn khdi lupng va do kich thirdc cdc mau gd frong timg diiu kiln mdi trudng. TlIp dd cdc mdu gd dupc ngdm frong nude cdt vd tiln hdnh cdn khdi lupng, do kich thudc sau mdi 6 gid cho din khi dat kich thudc khdng ddi (dat frang thdi bdo hda nude thdm), do kich thudc vd cdn khdi lupng cdc mdu gd d frang thdi bdo hda nudc tham.
b. Xdc djnh cdc chi tilu dn dinh kich thudc ciia gd Dp tdng khdi lirpng cua mdu gd WPG (weight percent gain) dupe tinh theo cdng thiic [4]:
\YPC — ^oi^i '^o-vi xl00,% (1) m, OU/
Trong dd: iriotxi vd mcxr khdi lupng khd kilt ciia mdu gd trude xtr ly vd sau xtr ly, g.
Khdi lupng thi tich khd kilt ciia mau gd trude khi xii ly vd sau khi xii ly theo cdng thiic:
ro=—, i - . g / c m ' (2) Ixaxb
Trong dd: m - khdi lupng mdu gd, g; 1, a, b - kich thudc mau gd tuong iing theo cdc chiiu dpc thd, xuyIn tdm, tiip tuyIn, mm.
+) Dp tdng khdi lupng thi tich dupe tinh theo cdng thtic [4]:
^01x1
Trong dd: JOM vd yosxi - tuong ting khdi lupng till tich khd kilt cua mdu gd tnrde vd sau xir ly, g/cm'.
Dd dm ciia mdu gd d cdc thdi diim dd cdn khdi lupng tuong ling vdi dd dm thdng bdng ciia gd frong diiu kiln tirong iing dd luu giii mdu gd vd dupc tinh theo cdng thiic:
w,=-
nir,Trong dd: Wj - dd dm mau go tai thdi diim dd xdc djnh khdi lupng vd kich thudc, %; mj - khdi lupng mdu gd tai thdi diim can mau (khi mdu dat khdi lupng khdng ddi frong qua trinh luu giir frong diiu ki|n nhdt djnh), g; HIQ - khdi lupng khd kilt ciia mau gd.g.
NONG NGHlfP VA PHAT TRIEN NONG THON - KY 1 THANG 9/2011 93
KHOA HOC CdNG NGHE +) Ty ll dan nd ciia gd d cac thdi diem khi gd dat
dp dm dn djnh dupc xdc djnh theo cdng thiic [4]:
Y, = (KT^-KT,) (5)
KT
ASE =^^^-^x\00,%
Y
(6)
jclOO,%
Trong dd: KTj- kich tiiudc (theo chiiu xuyIn tam hodc tiip tuyIn) cua mdu gd tai thdi diim i, mm
(frong bai bdo la kich thirdc theo chieu tiep tuyIn);
KTo - kich thudc cua mau gd d frang thai khd kilt, mm;
T HI sd chdng dan nd ASE (antiswelling efficient) dupc tinh theo cdng thiic [4]:
Bang 1. Kit qud xdc dinh khdi lupng
Trong do: Y^c va Y^ - tuong iing ty ll dan nd ldn nhdt cua mdu ddi chiing vd mdu xii ly, %.
•.KET QUA NGHEN CUU
1. Anh hudng cua ndng dd dung djch DMDHEU din lupng thdm hod chdt vd dO tdng khdi lupng thi tich
Kit qua xdc djnh cdc chi tilu: khdi lupng thi tich khd kilt ban ddu (trudc tam), khdi lupng thi tich kho kilt sau tdm, dp tdng lupng hod chat (WPG), dp tdng khdi lupng till tich khd kilt dupc tdng hpp vd dua ra d bdng 1.
thi tich, dp tang khdi lupng ciia gd Chi dp thi nghilm
(seri mdu) DC K10%
K20%
K30%
K35%
K40%
LK10%
LK20%
LK30%
LK35%
LK40%
Ndng dp hda chat DMDHEU, %
10 20 30 35 40 10 20 30 35 40
Yobd.
g/cm^
0,537 0,537 0,537 0,537 0,537 0,537 0,531 0,531 0,531 0,531 0.531
Yos.t4m,g/cm^
0,537 0,569 0,592 0,606 0,612 0,615 0,575 0,597 0,613 0,632 0,637
WPG,%
0,00 9,85 14,73 17,95 19,67 20,34 12,16 17,37 21,36 25,30 26,24
BTkitt, %
0,00 5,96 10,26 12,75 13,97 14,43 8,33 12,35 15,32 18,94 19,85
Trong dd: DC- seri miu doi chung; K10%, K20%, K30%, K35%, K40%- cac seri miu khdng luge truac Mu tim hda chit vai nong do hda chit DMDHEU lan lugt li 10%, 20%. 30%, 35%. 40%; LK10%. LK20%. LK30%
LK35%, LK40% - cic seri miu dugc luge trudc khi tim hda chit vdi nong do hda chit DMDHEU lan lugt la 10%. 20%. 30%. 35%, 40%.
Tir kit qua d bang 1 dd xdy dung dupc bilu dd (hinh 3) thi hiln mdi quan hi giiia ndng dp hda chdt DMDHEU din dp tdng lupng hod chat frong gd vd dp tdng vl khdi lupng thi tich (hinh 4). Kit qua thu dupe cho thay, khi ndng dp hda chat DMDHEU tdng, dp tdng khdi lupng ciia gd xtr ly tdng. Kit qua phan tich phuong sai vd so sdnh timg cdp cho thay cd su khac nhau vl dp tdng khdi lupng giiia cdc chi dp xur ly khdc nhau vl ndng dp hda chat frong dd cd sir khdc biit rd rlt vl dp tdng khdi lupng ciia cdc chi dp vdi ndng do 10%, 20%, 30%, 35%, cdn ciia cdc chi dp vdi ndng dp 35% va 40% cd sir khdc biit nhung khdng ldn. Dieu nay giai thich bdi kha ndng xam nhap hda chat vdo gd khdng tdng nhilu khi ndng dp ldn. Ndi cdch khdc ndng dp hda chat cao gdy khd khdn nhat
djnh cho vile thdm thau hda chat vao gd frong cimg diiu kiln vl thdng sd cdng nghi tam.
Dd timg khdi lupng ctia gd thudc cac chi dp thi nghilm mdu dupc lupc va khdng dupc lupc trudc khi tdm hda chat cimg ndng dd cd str khdc hilt rd rlt Diiu dd chting td rdng, mau gd dupe lupc trudc c6 kha ndng tham hda chat cao hon nin cd dp tdng khdi lupng cao hon. Dp tdng khdi lupng ciia mau gd thudc cdc chi dp thi nghi|m mdu khdng ludc xii ly hda chat ndng dd 10, 20, 30, 35, 40% ldn lupt la 9,85%, 14,73%, 17,95%, 19,67% vd 20,34%, frong khi dd dd tdng khdi lupng ciia go thudc chi dp mdu dupc ludc tiudc tirong iing la 12,16%, 17,37%, 21,36%, 25,30% vd 26,24%. Dp chenh lich vl dp tdng khdi lupng (dd chinh lech vl WPG) giiia mau dupc ludc vd khdng dupc ludc khi xti ly hda chat d cac ndng dp 10,20,30, 94 NONG NGHIEP VA PHAT TRIEN NONG THON - KY 1 THANG 9/2011
KHOA HQC
C Q N G N G H I35, 40% ldn lupt Id 23,48%, 17,92%, 19,01%, 28,64%, 29,02%. Cd till tiidy rdng, khi gd dupc ludc trude khi tdm hda chdt kha ndng thdm hda chat ciia gd tdng lln vd khi ndng dd hda chat cao lupng hda chdt vdo mdu dupc ludc tdng dang kl so vdi mdu khdng ludc.
Khdi lupng till tich khd kilt ciia mdu gd sau xti ly hda chdt tdng lln so vdi trudc khi xu ly, khdi lupng till tich ciia mdu xu ly d cac chi dp diu ldn hon khdi lupng thi tich khd kilt ciia mdu ddi chting. Khdi lupng thi tich khd kilt ciia mau gd khdng ludc trudc xit ly bdng 0,537 g/cm^ cdn khdi
tAm DIMHEDU
m-ii
i ^
^
ii
2 0 3 0 3 5 4 0
lupng thi tich khd ki|t ciia mau gd khdng lupc xti ly hda chdt ndng dd 10, 20, 30, 35, 40% ldn lupt la 0,569, 0,592, 0,606, 0,612, 0,615 g/cm^ tdng 5,96%, 10,26%, 12,75%, 13,97%, 14,43% so vdi chi tilu nay cua mdu trude xu ly. Vdi cac mdu dupe ludc trudc khdi lupng thi tich khd kilt mau trudc xii ly vd mdu ddi chting bdng 0,531 g/cml Khdi lupng thi tich khd kilt ciia cdc mdu gd ludc sau dd xir ly hda chdt ndng dd 10, 20, 30, 35, 40% ldn lupt Id 0,575, 0,597, 0,613, 0,632, 0,637 g/cm^ tdng 8,33%, 12,35%, 15,32%, 18,94% vd 19,85%.
2 0 3 0 3 5
Hinh 3. Anh hudng ciia ndng dd DMDHEU din dd tdng khdi lupng ciia gd frdm trdng
Mau xti ly d cdc chi dp diu tdng khdi lupng khd kilt (hay cdn gpi Id dp tdng khdi lupng - WPG) vd tdng khdi lupng thi tich khd ki|t nhimg dp tdng khdi lupng ldn hon dp tdng khdi lupng thi tich. Dd la do hda chat DMDHEU dd thdm vdo gd, vdo vdch tl bdo gd, mdt phdn da phan ting vdi thanh phdn hda hpc gd, nhdm OH dupe thi va cac vi mao dan trong vdch tl bao dupc ndi rpng, dan din kich thudc vd thi tich
Hinh 4. Anh hudng ciia ndng dd DMDHEU din dd tdng khdi lupng thi tich ctia gd trdm trdng
mdu gd tdng lln so vdi mdu gd trudc xii ly d cimg dp dm. Chinh vi thi khdi lupng thi tich khd ki|t ciia gd tdng d mtic dp it hon khdi lupng khd ki|t Do hi|u ting tdng thi tich ndy md miic dp thay ddi ldn nhdt vl kich thirdc va thi tich gd ciia mdu xii ly gidm so vdi mau gd khdng xii ly (ddi chirng).
2. Xdc djnh dd dm gd vd ty 1| ddn nd ciia gd frong cdc diiu ki|n mdi trudng khdc nhau
Chi dp thi nghidm (seri-mdu)
DC K10%
K20%
K30%
K35%
K40%
LK10%
LK20%
LK30%
LK35%
LK40%
Bdng 2. K i t qua xdc djnh dd dm vd ty 1 | ddn nd theo chiiu til (p =
Wi,%
10,42 7,79 7,59 7,52 7,55 7,36 7,83 7,65 8,04 7,19 7,18
55%
Ytti, %
2,40 1,57 1,43 1,37 1,31 1,33 1,59 1,38 1,33 1,24 1,27
(p = 65%
w„%
12,37 9,29 9,04 8,81 8,76 8,75 9,53 9,68 8,63 8,47 8,40
Ytt2>
% 2,84 1,92 1.71 1,59 1,53 1,51 1,87 1.71 1,55 1,48 1.47
(p = 75%
W3, % 14,79 13,56 13,51 14,18 13,13 13,64 13,43 13,33 13,04 13,58 13,06
Ytt3. ^
3,45 2,84 2,59 2,48 2,29 2,35 2,83 2,63 2,38 2,28 2.30
(p = 92%
W4,%
23,58 16,99 16,60 16,05 15,66 15,11 16,85 16,16 15,41 15,07 15.01
Ytt4. %
5.34 3.60 3,15 2,94 2,69 2,54 3,51 3,14 2,79 2,67 2,65
p tuyIn ciia gd Da ngam frong
nudc W5,%
33,12 20,50 20,10 19,60 19,20 19,00 20,13 19,78 19,16 18.74 18,55
Ytis. %
5,52 4,11 3,68 3,38 3,18 3,09 3,91 3,47 3,11 2,92 2,89
Da ngam trong nudc W6,%
44,57 31,57 30,37 29,87 29,14 29,08 30,95 30,16 29,67 29,21 29,16
Ytt6>%
6,81 4,11 3,68 3,38 3,18 3,09 3,91 3,47 3,11 2.92 2,89 N 6 N G NGHIEP VA
PHAT TRIEN
N 6 N G TH6N- KY 1 THANG 9/2011
95KHOA HQC C Q N G NGHE Kit qud d bang 2 cd thi thay rdng, frong cimg
diiu kiln luu giir dp am ciia cac mdu gd xii ly hda chat ludn ludn thdp hon dp am mau gd ddi chting. Cd sir khdc hilt rd rlt vl dp am cua mdu ddi chiing vd cdc mau xtr ly, cdn dp am cua mdu xu ly d cac chi dp khdc nhau khdng khac biit nhilu. Khi luu giu frong diiu kiln mdi trudng cd nhilt dp khoang 20"C vd dp dm tuong ddi 92%, dd am ctia mau ddi chiing Id 23,58%, dp am ciia mdu khdng ludc xu ly hda chdt ndng dp 10, 20, 30, 35, 40% ldn lupt la 16,99%, 16,60%, 16,05%, 15,04%, 15,11% va ciia mau dupc ludc trude xu ly hda chdt tirong irng la 16,85%, 16,16%, 15,41%, 15,07% vd 15,01%.
Tir bang 2 cd thi xdy dung dupc dd tiij thi hiln mdi quan he giira dp dm gd va ty ll dan nd theo chiiu tiep tuyIn ciia gd d cdc dp am tuong iing, dd thj dupe xdy dung cho cdc seri tiii nghilm da niu frIn vd dupe dua ra d hinh 2. Kit qua d bang 2 ciing cho
thay, khi Itm giir frong ciing diiu ki|n ty 11 ddn nd ctia mau ddi chiing ludn ldn hon ty ll dan nd ctia mdu xu ly d cac chi dd: frong diiu kiln dp dm 55% ty ll ddn nd theo chiiu tiip tuyIn ciia mdu ddi chting la 2,4%, frong khi dd chi tilu nay ciia cac mdu khdng lupc xtr ly hda chat ndng dp 10, 20, 30, 35, 40% tuong irng Id 1,57%, 1,43%, 1,37%, 1,31% vd 1,33%. Trong diiu kiln luu giQ vdi dd am mdi trudng 55%, 65%, 75%
chinh lich vl dp am gd ciia mau ddi chiing vd mdu xii ly it hon nhilu khi luu giii frong diiu kiln dp dm 92%. O dp am 92% dp am gd ciia mau ddi chiing la 23,58%, frong khi dd dp dm gd ciia mau khdng lupc xir ly hda chdt ndng dp 10, 20, 30, 35, 40% ldn lupt la 16,99%, 16,60%, 16,05%, 15,66%, 15,11% vd chi tilu nay ciia mau lupc vd xii ly hda chdt tuong iing Id 16,85%, 16,16%, 15,41%, 15,07%, 15,01%. Diiu dd chirng td rdng dd dm mdi trudng tdng nhung khd ndng hiit dm cua cdc mdu xti ly tdng rat it vd tiln tdi dat gid fri ctic dai.
Dp dm gd, % Dp dm gd, %
B
^ tf^
- • - O C - • - K 1 0 % - * - L K 1 0 % -M-K2I»I>
- * - L K 2 0 %
'§
dan
<i>
'&
20.00 30.00 40.00 50.00 0.00 30.00
c Dddmgd,% d Ddamg6,%
Hinh 5. Quan h | giira dd dm gd vd ty 1| ddn nd ciia gd trdm frdng a- mau ddi chirng vd mau khdng dupe lupc trudc xu ly DMDHEU;
b- mau ddi chiing vd mau dtrpc lupc trudc xii ly DMDHEU;
c- Mdu ddi chiing, mau dupc ludc vd khdng ludc xii ly DMDHEU ndng dp 10% va 20%;
d- Mdu ddi chiing, mau dupe ludc vd khdng lupc xii ly DMDHEU ndng dp 30%, 35% vd 40%;
3. Anh hudng cua ndng d^ dung djch DMDHEU ^oi chiing. Nhung dd xdc djnh dupc ty 1| ddn nd ldn din h | sd chdng ddn nd ASE "^^t ^"^ So, o ddy dua ra kit qua xdc djnh ty 1| dan
^ . . , , , . . ^, , , ., . . . ^ . .. nd tiieo chiiu tiip tuyln. Tir kit qua xdc djnh ty 11 Do dilu kien thi nghilm khong tao duoc moi , . , ,, , .-.^ - ^ ... i i , .- , .- , . AOC
^ . , , . . ' • . . . . - • ^ ' r^^v » 1, . dan no Ion nhat cua go tinh hi so chong dan no ASE, truong CO do am moi truong xap xi 100% nin khong * - , . . , , , .^ , ./ , ', /, , „v
- ii L if • ^. L . .' 1. iTv. ' X , ,, , da xac dinh h i so chong ddn no (bang 3).
xac dinh dupe dp hut am Ion nhat cua mau xu ly va
96 NONG NGHIEP VA PHAT TRIEN NONG THON KY 1 - THANG 9/2011
KHOA HQC CbNG NGHE
STT 1 2 3 4 5 6 7 8 9 10 11
Chi dp tiii nghilm (seri
mau) DC K10%
K20%
K30%
K35%
K40%
LK10%
LK20%
LK30%
LK35%
LK40%
Bdng 3. Kit qud xdc djnh h | sd chdng ddn nd ASE Ndng dp hda
chat DMDHEU,
% - 10 20 30 35 40 10 20 30 35 40
Dp tdng khdi lupng WPG, %
9,85 14,73 17,95 19,67 20,34 12,16 17,37 21,36 25,30 26,24
Ty 11 dan nd ldn nhdt theo chiiu
tiip tuyln, % 6,81 4,11 3,68 3,38 3,18 3,09 3,91 3,47 3,11 2,92 2,89
HI sd chdng ddnnoASE, %
0,00 39,63 46,00 50,33 53,33 54,53 42,55 49,02 54,31 57,10 57,54 Tir kit qua d bang 3 cd thi xdy dung dd thj thi
hiln mdi quan h i giiia ndng dp DMDHEU vdi dp tdng khdi lupng gd Oupng hda chat vdo gd) vd giiia dp tdng khdi lupng vdi he sd chdng dan nd ASE (hinh 6, 7). Ty ll ddn nd ldn nhat tiieo chiiu tiip tuyln ctia mdu ddi chiing ldn hon chi tilu ndy ciia mau xtr ly d tat cd cdc chi dp, h i sd chdng ddn nd ciia mdu d tat cd cdc chi dp xii ly dat tir 39,63% din 57.54%, chting td qua frinh xtr ly hda chat DMDHEU cho hi|u qua vl dn djnh kich thudc gd. Tir kit qua d bang 3 vd dd thj hinh 6, 7 cd till tiiay, khi ndng dp hda chat tdng thi lupng hda chat vdo gd tdng vd h i sd ASE tdng nhung mtic dp tdng khdng gidng nhau d cac cap ndng dp vd vdi hai trudng hpp mau qua ludc vd khdng qua lupc.
Mdu qua xtr ly ludc ludn ludn cd lupng hda chat vao gd vd h i sd chdng dan nd cao hon frong ciing
dilu kiln xii ly (ciing ndng dp hda chdt), dd Id do gd xu ly ludc trudc cd khd ndng thdm hda chdt cao hon [1]. Khi xii ly hda chdt ndng dp 35% vd 40% tiii str khdc bi|t vl dp tdng khdi lupng gd vd h i sd ASE khdng nhilu. Chiing td rdng frong dilu kiln tdm dd lua chpn vdi ndng dp hda chat 40% khdng ldm tdng nhilu hieu qud so vdi ndng dp 35% dting frIn phuong diln lupng hda chat vdo gd vd dn djnh kich thudc gd.
Chinh vi thi, vdi gd frdm frdng khdi lupng thi tich khd kilt frong khoang 0,52-0,54 g/cm^ niu tdm hda chat DMDHEU frong dilu ki|n: nit chdn khdng din 70 kPa frong 30 phiit, tam dp luc d 0,8 MPa frong 90 phiit khdng nin sir dung hda chdt ndng dd 40% vd cao hon niu xii ly vdi miic tilu tdng tinh dn djnh kich thudc gd. Trong tnrdng hpp sii dung hda chat ndng dp ndy cdn phdi tdng dp lire tdm vd thdi gian tam.
l o a o 3o 3 5 IvAniK d o l > i v i l > l l l ' : c i .
- * o
5; 8 0
I 60 I 4 0
n K-mSu khdng luOc trudc khi l l m DMUIinU
C I.K-mfiu B5 IUOC lru6c khi l l m DMOl IIZU
1 0 20 30 35
N&ng d $ D M D H E U , V .
Hinh 6. Quan h | giiia ndng dd DMDHEU vd do tdng khdi lupng gd
IV. K ^ LUAN
Xir ly hda chdt DMDHEU ndng dp 10, 20. 30, 35, 40% vdi 5,5% chdt xtic tac clorua magil (ty i | tinh tiieo khdi lupng chdt xiic tdc vd DMDHEU) vd xir ly nhi^t sau tdm (curing) a nhilt dd 120°C frong tiidi
Hinh 7. Quan h | gifta ndng dd DMDHEU vd h | sd chdng ddn nd ASE
gian 12 gid da ldm tdng tinh dn djnh kich tiiudc gd, cu thi nhu sau:
Khdi lupng khd ki|t ciia gd tdng till hi|n qua dd tdng khdi lupng WPG, hi sd ciia WPG ctia mdu tiiudc cdc chi dp xti ly dat tit 9,85% din 26,24%,
NONG NGHlfP VA PHAT TRIEN N 6 N G T H 6 N KY 1 THANG 9/201 1 97
KHOA HQC C Q N G NGHI
chimg td hda chat da tham vdo gd. Trong dd lupng hda chdt vdo gd tdng lln cimg vdi su tdng lln cua ndng dp hda chdt Dp tdng khdi lupng ciia mau thudc cdc chi dp vdi ndng dp 10, 20, 30, 35% khdc nhau rd rlt, cdn giiia hai chi dp vdi ndng dp 35% va 40% cd sir khac biit khdng nhilu. Dp tang khdi lupng ciia mdu dupe ludc trude khi xii ly hda chat ludn ludn ldn hon chi tieu nay ciia mdu khdng lupc.
- Khdi lupng t h i tich khd kilt ciia mau sau xu ly tdng so vdi trude xii ly, ciia mdu xti ly tdng so vdi mau ddi chiing. Khdi lupng t h i tich khd kilt ciia mdu trude xu ly vd mdu ddi chiing Id 0,537 g/cm^, cdn ciia mdu xtr ly dat tir 0,569 din 0,637 g/cm^ tdng tir 5,96%
din 19,85% so vdi tnrde xu ly. Miic dp tdng v l khdi lupng t h i tich it hon mue dd tdng khdi lupng do khi xur ly hda chdt DMDHEU hda chat ndy dd vdo gd vd mdt phdn tham gia phan ling vdi thdnh phdn hda hpc gd, mpt phdn ttr polune hda frong gd lam tdng kich thudc vdch t l bdo gd ddn din tdng kich thudc gd (thi tich gd tdng lln).
Dd dm gd ciia mdu ddi chting ldn hon ciia mdu xii ly khi luu giu frong ciing dilu kiln mdi trudng. 0 dieu kiln mdi trudng vdi nhilt dp (20±2)''C vd dp am
(6503)% dp am ciia mau ddi chiing Id 12,37%, frong khi dd dp am ctia mdu xii ly dat 9,68% din 8,40%.
Ty ll ddn nd ldn nhdt theo chiiu tiip tuyln ciia mau ddi chiing la 6,81%, cdn chi tilu nay ciia mau xii
ly la 4,11% din 2,89%, tiiong iing vdi h i sd ASE dat 39,63% din 57,54%.
TAIUEUTHAMKHAO
1. Ta Thj Phuong Hoa, 2011. Anh huang cua xvt ly thuy nhiet din thinh phan hda hgc. tinh chit caly
chu yiu. kha ning thim dung dich hda chit DMDHEU cua gd Trim tidng. Tap chi Ndng nghilp vd Phdt trien ndng thdn. Sd 13/2011.
2. Ta Thj Phuong Hoa, 2010. Bio do kit qua chuyin di "Biin tinh gd bing phuong phip hda hgc". Trudng Dai hpc Lam nghilp, Vi|n Khoa hpc Lam nghilp Viet Nam.
3. TCVN 8048-116: 2009. GS - Phuong phip tiid caly.
4. Galium A S. Hill, 2006. Wood modification, chemical, thermal and other processes. John Wiley
& Sons, Ltd.
5. Wood science and technology 27, H. Militz, 1993. Treatment of timber with water soluble dimethylol resins to improve their dimensional stability and durability.
6. rOCT 16483.21-72*. 'JipeeecuHo. Memodu omdopa odpsifoe djin onpedeneuuH ^^'USUKO-
MexoHUuecKux ceoUcme nocjie mexHOJioeuuecKoU o6pa6omKU ".
THE STUDY ON DIMENSIONAL STABILITY OF TREATED WOOD CANARIUMALBUMQY DMDHEU Ta Thi Phuong Hoa Summary
The study on dimensional stability of freated Canarium album wood by DMDHEU (dimethyl dihydroxide ethyleneurea) with concenfrations of 10%, 20%, 30%, 35%, 40% in two conditions: boiled wood samples at temperature 70''C and unboiled wood samples before DMDHEU impregnating. The dimensional stability of the freated wood is increased with these concentrations and 5.5% MgClz catalyst The weight percent gain after DMDHEU freating is from 9.85% to 26.24%, suggesting that tiie DMDHEU has impregnated into tiie wood. The amount of DMDHEU impregnated will increase when its concentration is increasing from 10%
to 35%, but then this value is almost unchanged in the range of 35-40% concenfrations. The oven dry density of wood samples before freating and confrol samples are 0.537 g/cm'. The oven dry density of freated wood samples is from 0.569 to 0.637 g/cm', equivalent to 5.96% to 19.85% increasing. The properties of freated wood is as follow: the weight increasing (indicate the amount of DMDHEU impregnated increaing); the density increasing of boiled samples is higher than that of unboiled samples. The EMC of freated wood is also lower than that of confrol samples while keeping in the same condition. In the conditions of 20t2''C temperature and 65±3% relative humidity, the EMC of confrol sample is 12.37%, while the EMC of freated wood is rather low at 9.68% to 8.4%. The largest swelling rate in the tangential direction of confrol samples is 6.81%, but the swelling rate of freated wood is just 4.11% to 2.89%, equivalent to 39.63%
to 57.54% of anti-swelling efficient (ASE). However, for the freated samples of same weight percent gain value, there is no difference in the ASE v-f boiled and unboiled samples before DMDHEU impregnating.
Keywords: Canarium album, dimensional stability, DMDHEU.
Ngudi phdn bi^n: GS.TS. Hd Chu Chir
98 NONG NGHIEP VA PHAT TRIEN NONG T H 6 N KY 1 - THANG 9/2011
THE LE VIET VA GUI BAI
1. Tap chi Nong nghiep va Phat triln nong thdn (ISSN 0866 - 7020) cong b6 cac cong trinh nghien ctiu, cac bai tong quan va thong bao khoa hoc thuoc nganh Nong nghiep va Phat triln nong thon;
chua dang a cac an pham khac.
2. Bai viet dugc scan thao tren may vi tinh, sii dung UNICODE font Times New Roman, sdp xIp theo cac phan theo thu ttr nhu sau:
TEN BAI: Chii: in. Font 14 bold
TEN TAC GIA: Chii thuang. Font 12 bold, vai foot notes la ten ca quan cho (cac) tac gia va dia chi tac gia de lien he (corresponding author)
TOM TAT: font 10, it nhat 250 tir va khong qua 350 ttr trong mot doan van, khong xudng hang. Tii khoa: 5 - 7 ttr, xep theo thu tu A - Z.
M6 D A U / D A T VAN DE: font 12
NGUYEN/VAT LIEU VA PHLTONG P H A P : font 12
KET QUA vA T H A O LUAN: font 12 (co thi tach rieng phdn KET QUA va T H A O LUAN) KET LUAN: font 12
TAI LIEU THAM K H A O : font 10 Phan tieng Anh a cuoi bai gdm:
TEN BAI TIENG ANH: Chflr in, Font 14, bold
TEN TAC GlA: Khong bo ddu, chir thuang, font 12 bold, footnotes cho tac gia dl lien he (corresponding author)
SUMMARY (tieng Anh): font 10, mpt doan van 250-350 tir khong xudng hang.
Keywords: (tieng Anh), 5-7 tir, xep theo thti tir A - Z.
3. Mpt so huang dan can thiet 3.1. Cach viet tai lieu tham khao
Trong bai viet, tai lieu dugc trich dan bang each ghi ten tac gia, nam xuat ban trong ngoac dan ();
neu CO 2 tac gia thi diing dau phay (,), 3 tac gia trd len thi ghi tac gia dau + et al., nam, vi du: (Nguyin Van A et al., 2005). Khi dua ten tac gia vao cau van thi thay dau (,) giiia hai tac gia thanh chii "va", thay cum tir "e/ al." bang cum ttr "dong tac gia", nam de trong ngoac dan, vi du: ... Nguyen Van A va Tran Van B (2006)...., .. .Nguyen Van A va dong tac gia (2005). Tai lieu tham khao sap xep theo thti tir A - Z;
ten tap chi quoc te viet tat theo quy dinh quoc te, khong co dau cham sau chCr viet tat. Tham khao Danh muc viet tat cac Tap chi Quoc te tren mang Pubmed tai trang Web sau:
(http://www.ncbi.nlm.nih.gov/entrez/journals/noprov/loftextJull_noprov.htmt); ten tap chi trong nuac, ten sach va cac tai lieu khac viet day dii; thti tu viet: Hp, ten. cac tac gia - nam xuat ban - ten sach, ten bai bao - ten tap chi doi vai bai bao, hoac ten nha xuat ban va nai xuat ban doi vai sach - tap, so - trang dau va trang cuoi ctia tai lieu.
Dac biet luu y, chi nhiing trich dan neu trong bai mai dugc ghi vao Tai Heu tham khao.
3.2. Hinh va bang: Hinh (bao gom hinh ve, anh, do thj, sa do, bieu do,..) phai co tinh khoa hpc, bao dam chdt lugng va thdm my, dat dting vi tri trong bai, co chii thich cac ky hieu; ten hinh va bang phai ngan gon, du thong tin; ten hinh va so thii tu ghi a dudi hinh, doi voi bang, ten va so thti tu ghi a tren bang.
4. Bai vilt phai sir dung cac thuat ngir, danh phap khoa hgc pho bien; cac thuat ngir chua Viet hoa thi uu tien diing nguyen ban tieng Anh, doi vai cac ngon ngii khong thuoc he La tinh thi phai co phien am La tinh va chti thich ro rang. Neu diing nhieu ttr viet tat thi phai co danh muc cac tir viet tat sau phan Summary. Cac thuat ngir, danh phap khoa hgc, dan vi do luang thong dung dugc viet tat khong can chti thich theo dting quy dinh chung cua nha nuac va qu6c te.
5. Ban thao giri dang gom 1 ban in chinh va 1 ban dien tu. Bai tong quan khong qua 15 trang in, bai bao khong qua 10 trang in va thong bao khong qua 5 trang in. Tap chi khong nhan dang cac bai khong dung quy dinh neu tren. Bai khong dang khong tra lai ban thao.
6. Nhom tac gia dugc tang 1 cuon tap chi c6 bai dugc dang.
7. Mgi giao dich xin lien he theo dja chi sau:
Toa soan Tap chi Nong nghiep va Phat trien nong thon, 86 10 Nguyen Cong Hoan, Ba Dinh, Ha Ngi.
Dien thoai (04) 37711069 - 37711070; Fax: (04) 37711073; E-mail: [email protected]
