i^viiy iiyiiicy luiijf
KHA NANG KHANG NAM CUA VAN MONG G 6 BEECH BIEN TINH VOd CAC HOP C H A T CO CHlTA N-METHYLOL MELAMIN
Trinh Hiln Mai
TS. Throng Dai hoc Ldm nghiep T6M TAT
Cdc gidi phdp bao qudn vd bi€n tinh gS dd g6p phan cdi thifn d$ b^n sinh hpc, k t o ddi th£ri gian sii dung cho gS vd san phdm tir g§. Cac c6ng trinh nghien ciiu tren the gidi cho tfady gS biln tinh vdi cdc lo&i nh\ra melamin cd khd ndng Idm giam s\r phd hu^ ciia ndm myc vd nam biln mdu ciing nhu tang kha ndng ch6iig chiu cdc dilu ki^n moi tniong. Tuy nhi€n, chua cd nghiSn ciiu ndo ddnh gid khd ndng khdng n4m ciia vdn mdng gS Beech bien tinh vdi cdc hop chit c6 chtra N-methylol melamin. Bdi bdo ndy trinh bdy kit qud nghiin cihi khd ndng khdng n i m muc tilng {T. versicolor), nim myc ndu (C. puteana), vd nam biln mdu (A. pullulam) ctia vdn mong g§ Beech (Fagus sylvatica) bien tinh vdi hai hop chit cd thdnh phdn chiia N-methylol melamin. Kit qud cho thiy: vdn mong g§ Beech bien tinh vdi hai hop chit cd chiia N-methylol melamine d cdc hdm Iirgng khd ciia hda chit tit 5-20% cd khd nang khdng nim t i t . Ngodi ra, khi hdm luong khd cua hda chit tdng, t J 1| tin hao khdi luong ciia vdn mdng do sy phd hiiy ciia n i m myc (T. versicolor vd C. puteana) cd xu hirdng gidm, cdn miic do biln mdu do n i m A. pullulans ciia vdn mdng biln tinh chju anh hudng Ididng dang k l ciia hdm lupng khd ciia hda chit.
Tii khda: Beecfi, N-methylol melamin, ndm myc, ndm biin mau, vdn mdng I. »4iT VAN DE
Cac loai nSm myc, nam bien mau vS n i m moc gdy ra nliung tlliet lijii dang ki vS gia tri Idnli te cho go va cac san pliSm tir go trong qua trinli sic d\mg. N ^ muc c6 idld nang pha hiiy vach te Mo nghiem trong va lam giam khdi luiyng ciing nhu cuong do ca hoc ciia go.
Trong Ichi do, n i m biSn m i u v4 n i m mdc phat trien bang each sir dung cac hop chit huu c a dit tru trong gS, chiing khong gay anh hudng hojc anh huong khong dang k l d&i tinh chit ca ly ctia g5, chi lam bien mau b l mat g6, lam giam chit lupng go (Eaton va Hale, 1993;
Haygreen va Bowyer, 2003).
Ben canh nhiing gi4i phdp bdo quan go thong thu6ng la su dung cac loji thudc bao quan c6 kha nang phong ngira va diet cdc loai nam hai go, biln tinh gd mang din mOt giai phdp hiiu hi$u d l cdi thien kha nang chdng nim cho g5, ma khdng gay doc hai cho mdi trudng (HU, 2002; Rowell, 1983). G§ thdng va beech biln tinh vcH dung dich dimethylol dihydroxyethyleneurea ( D M D H J E U ) it ndng do 30% trd len da han chi dang ke su xam hai ciia nam bidn mdu, n i m muc nau vd nam muc trdng (Pfefifer et al., 2011, Dieste, 2008). Gd European larch (Larix decidua Mill.) biln tinh vdi dung dich methanol-etherificated-melamin
d hdm luijmg khd thip (7,5%) cung dem lai hidu qua ching n i m khd tdt (Rapp vd Peek, 1996). Kha nang khang n i m muc nau, nim myic trdng va n i m biln mau cua go Beech) vd gd Thdng biln tinh voi dung djch N- methylol/parafBn tdi ty Id tang khdi lu(mg (WPG) 15-21% da dugc cai thien ro ret so vdi gd ddi chiing (Nguyen et al, 2007).
Trong nghien ciiu nay, khd nang khdng nim muc trang (T. versicolor), ndm muc nan (C. puteana, va n i m biln mdu (A. pullulam) cua van mdng go Beech biln tinh vdi hai hop chat cd thdnh phdn chiia N-methylol melamin da duoc nghien ciru vd danh gia.
ttVATUfUVAPHUtiNGPHAPNGHlftNCtltJ 2.1. Hda chat
Dung dich N-methylol-melamine (lvIMM-1) cd tSn thuang mai la Madurit MW 840/75 WA (dugc cung cdp bdi cdng ty Ineos Melamines, Frankiiirt/Mam, Diic). Do nhdt ddng cua dung dich hda chit Id 430 mPas, trong luong ridng 1,256 g/ml, vd gid tri dp pH la 9,3 (tit cd deu d nhi$t do 25°C). NMM-1 cd mot phin la methylolated (vdi cac nhdm amino ciia melamine) vd mdt p h i n la methylated; dac diem ciia NMM-1 la ki nude va cd khd nang ddng ran.
T ^ CHi KHOA HOC VA C 6 N G NGHE LAM NGHIEP SO 4 - 2013 67
i>png ngniep nmg
Dung dich N-methylol-melamine bien tinh voi axit beo, cd chiia paraffin (mNMM-2) cd tdn thuang m^ la Phobotex VFN (dugc cung cip bdi cdng ty Ciba, Basel, Thvy si). Nd la mot chit dang nhii tuong mdu trdng, trgng lugng riSng 0,991 g/ml, va gia trj dg pH la 5,3 (tit ca diu d nhidt do 25°C). Do dugc biln tinh vdi axit beo va cd chira thdnh phan paraffin.
hda chit nay cd dac dilm kj nuoc ndi trdi.
Dimg dich chdt xiic tac la mdt mudi nhdm cd ten thuong mai la Catalyst RB (dugc cung cdp bdi cdng ty Ciba, Basel, Th\iy si) dugc sil dung cCmg vdi hda chdt mNMM-2.
Cdc hda chit va chit xiic tic dugc sir dmg 6 dang dimg dich vdi ham lugng khd dugc trinh bdy trong bang 01.
Bsutg01.HambeangkhdciiahoachatvanSngd^ciiachitxtictdc(%)dui^dit^am^vdninoi^
JTT Hoa chdt Ham lugng khd (%) Xuc tac Ndng dg cua chat xiic tac (%) 1
2 3 4 5 6 7
NMM-1 NMM-1 NMM-1 mNMM-2 mNMM-2 mNMM-2
-
20 10 5 10
5 10
-
-
RB
-
RB RB
3,8 1,9
2.2. Quy trinh xo- ly van mdng v6i h6n chSt Van mong go Beech
40 X 0,5 X 40 mm^
Pha hoa chat a cac n6ng do khac nhau
Ngam tam chSn khdng, ap l^c
i
Lau sach hoa chat dpng tren be m&t van mong
I
Say van mong a nhiet dg 40^C trong 24h
Curing van mong of 140°C trong 2h
I
NgSm van mong trong nuoc theo tiSu chuan EN 84
1
say van mong den kho kiet 6 chi do: 40°C, 24h, va 103X, 24h
DIt van mong trong phong 20*0, 65% RH
Xac dinh kha nang khang nam
muc nau
Xac dinh kha nang khang nam
m u c t r ^ g
Xac djnh kha nang khang ndm
bien mau Hinh 01. Qiiy trinh xdr ly vdn mdng vdi hda chat
T ^ C H i K H O A H Q C VA CONG N G H E L A M N G H I E P S 6 4 - 2013
\fUiiy iiynicfj luiiy
Van mong g6 Beech a dp im thang bang 8- 12% sau khi loai bo phan g6 loi dugrc cit voi kich thuac: 40 x 0,5 x 40 mm^ (xuyen tam x tiSp tuyln X doc thd). S6 lu(;mg: 10 van mdng biln tinh va 10 van mong doi chiing/mijc xii ly. Van mong dung dl bien tinh dugc ngam tdm d chi d^; chan khong (60 mbar) trong 30 ph6t va ap i\rc (12 bar) trong 2h voi cac dung dich hoa chdt (pha vol nuac tinh khilt) 6 cac ham lugfng kh6 va n6ng d6 nhu bang 01. Sau khi tim hoa chit, van m6ng dugc vot ra, lau s^h h6a chdt dgng a bl mat va say 6 nhi^t do 40''C trong 24h, sau do curing a 140°C trong 2h. Van mong khong xii 1;^ bien tinh, dugc diing 1 ^ van d&i chiing.
De loai bo phan hoa chat de bi riia troi doi vai van mong sau bien tinh va cac chat chiet suit tan trong nuac Ignh doi voi vM mong doi chiing, toan bo van mong tren dugc ngam trong nuoc lanh 14 :^ay voi 9 lan thay nuac theo tieu chuan EN 84. Tiip theo, v ^ m6ng dugc siy den khfi kiSt d chi do: 40°C trong 24h, sau do lOS'C trong 24h. Kh6i lugng ciia tung van mong 6 trang thai kho kiet dugc tmh la kh6i lugng ban dau, truac thi nghidm vl kha nSng kh^g ndm. Sau do van mong dugc d$t trong phong 20°C, 65% RH trong khoang 2 tuin dl hiit dm tra lai truac khi dira v ^ thi nghifm.
2.3. Thi nghifm xdc dfnh kha nang khdng nam Nguon cung cdp cdc logi ndm: nim biln mau Aureobasidium pullulans (de Bary) Amaud strain P 268 (DSM No. 3497), ndm myc nSu Coniophora puteana (Schum. Fr.) Karst. strain BAM Ebw. 15 (DSM No. 3085), va ndm muc tring Trametes versicolor (Linneus) L. Quelet strain CTB 863 A (DSM No. 3086) diing trong nghien ciiu nay dugc cung cip bai Trung tam vi sinh v^t ciia Diic (German Collection of Microorganisms and Cell Cultures DSMZ). Bao tu ndm A. pullulans dugc nuoi ciy trong dia co chua 2% m^ch nha- agar; bao tu nam C. puteana va T. versicolor dugc nuoi cdy trong dia co chiia 4% mach nha-
agar, duy tri nhigt d6 moi truong 22''C.
Thi nghidm xdc dinh Idid ndng khdng ndm muc ndu vd ndm muc trang
Kha nang khang nim muc tring (T. versicolor) \h nSm m\ic nau (C. puteana) ciia vdn mdng biln tinh dugc ddnh gid dira theo tieu chuan EN 113 va thi nghiem tuong ty cua Wepner va Militz (2005). De thuan tien cho vi?c lam s^h cac sgi nam ra khoi mlu van mong sau khi u trong nam, cac mau van mong (chuan bi nhu d muc 2.2) dugc bgc trong ludi th^P khdng gi cd kich thudc: chiSu ddi x chilu rgng x chilu day = 100 x 40 x i mm^; vdi kich thudc ciia mdt ludi 1 x i mm^. Sau khi bgc tCmg vdn mdng vao ludi th^p va ddng gdi trong tlii nilon, v ^ mdng dugc khur triing bang tia gamma. Tiip theo, cdc mdu vdn mdng biln tinh va ddi chiing dugc dlit trong cac dia c6 ciy sin nam T. versicolor h o ^ C. puteana, s6 lugng 4 van mdng/<£:^a nam, xen ke nhau giua mlu d6i chiing va mlu biln tinh, cdc thao tac va trinh tu thi nghigm dugc thuc hien theo diing quy djnh ciia tieu chuan EN 113. Ngoai ra, cd 5 ^ a nam x 4 naau van mdng ddi chiing dugc dung cho mdi loai ndm dl ddnh gid kha ndng phat trien ciia cdc logi nam trSn ^ a cfai d|t mlu doi chiing. Cac dia nam cd mau van mdng dugc dat trong phdng tdi, kin, duy tri mdi trudng (22 ± 1)°C vd dg dm tuang d6i (70 ± 5)% trong 8 tudn. Sau qua trinh ii tren, cac sgi nam tr6n be mat cua vdn mdng dugc loai bd bang dao cd diu nhon, can khdi lugng vdn mdng dl xdc dinh dO dm sau 8 tudn ii trong nam muc theo cdng thiic (1). Tiip theo, siy vdn mdi^ d 103°C din khd k i ^ tii dd xdc dinh dugc ty le tdn hao khdi lugng cOa vdn mdng do nim myc theo cdng thiic (2):
MC(%) = fc=^xl00 (1) WL(%) = ^^"'^'•f X100 (2) Trong do;
MC- do am cda mau van mdng sau thdi gian u trong ndm
T ^ CHI KHOA HQC VA CONG NGHE LAM NGHIEP S6 4 - 2013 69
vong ngtiiep ritng
WL- ty le tdn hao khdi lugng ciia van mdng Wa- khdi lugng kho kiet ciia vdn mdng sau thdi sau thdi gian u trong nam gian u trong nam
Wb- khdi lupng khd kiet ban ^ u cua van mdng Wm- khdi lugng cua van m d i ^ udt sau thdi gian (trudc khi li trong nam) u trong nam (sau khi lam sgch cdc sgi nam)
^ a) b) Hinh 02. a - Bia ndm gSm 2 mdu vdn biin tinh (U bi nam bao phu) vd 2 mdu vdn
chimg (bi nam bao phu nhieu)
b-Bia gom 4 mdu vdn doi chung (bi nam IMW phd todn b§) Thi nghiem xdc dinh kJid ndng khdng ndm
bien mdu
Khd nang khdng nam bien mau (A. pullulans) cua mau van mdng dugc thirc h i | n theo tieu chuan ndi bg ciia V i | n sinh hgc go vd san p h i m go, truong Dai hgc Tdng hgp G o e t d n ^ n , E)uc. Sau khi khu trung cdc m l u vdn mdng (d myc 2.2) bdng tia ganoma, dat 4
nmu vdn mdng/dia cd chiia 50 ml dung dich agar, xen ke nhau giua mau ddi chiing va m l u bien tinh. Mdt bao tu nam A. pullulans, mau den, hinh trdn, dudng kinh 1 cm dugc dat vdo trung tam cua mdi van mdng. Cdc dia agar cd mau van mdng va nam dugc dat trong phdng tdi, kin, duy tri mdi trudng (22 ± 1)°C vd dd am tuang ddi (70 ± 5)% trong 8 tudn.
BiiibQii.a-l^gdm2tnMav3nl»entmb(ndnibiSamaakb6nglanr^ng)v^2mSavdBdoicbiiiig (nam bien mdu lan rpng)
b - Hinh dnh sau khi scan vd dimg phdn mem xir ly dnh GIMP cua n0t so mdu vdn mdng binam
Nam bien mdu tren b l mat van mdng dugc lam sach bang bong gdn, tuy nhien mau den cua ndm thi v l n con nguyen tren vdn. De danh gid dien tich lan rgng cua ndm tren b l mat vdn
3000 (dg phan giai 300 dpi); dung phdn m i m xii ly dnh GIMP de tinh ty le dien tich van mdng bj bien mdu/di^n tich todn m l u vdn.
Phan lo?i muc do biln mdu theo ty le biln mdu m d i ^ scan b€ mdt vdn bdng mdy CanoScan dugc the hien d bang 02:
T ^ L P C H I K H O A H O C VA C O N G N G H $ L A M NGHIEP S 6 4 - 2013
lufViiy iiynicpiuny Bang 02. PhSn logi mire dp ndm biin mdu
theo ty 1$ bien mdu Loai
0 1 2 3 4 5
Ty le nam bien mau (%) 0 Bat dau CO vet nam, co vong
ttbn ciia bao tir nam
<20 20-50 5 0 - 7 5
>75 ra. KET QUA VA THAO LU.JN 3.1. Kha nang khing nim mfc tring (T. versicolor) vk nam muc nSu (C. puteana)
Sau 8 tuSn u trong nim, tit ca cac mau van
mong d6i chiing diu c6 dp Im Icin hem 20%, dat yeu ciu cua tieu chuin EN 113, do do thi nghi?m xdc dinh kha nang khang nim trong nghien cilu niy la hijp 1?. D6i vcri cdc thi n g h i ^ xic dinh khd nang khang nim, sai quan phuong (Standard deviation) thudng co thi rit Ion nhu a do th} hinh 04 va 06.
Voi cd hai lo^ nam T. versicolor vd C. puteana, ty 1? ton hao kh6i Iu(?ng ciia mdu vdn mong biln tinh gidm khi hdm luong khd ciia hoa chit bien tinh tang. Tuy nhiSn, van mong bien tinh vdi h6a chit niNMM-2 (khong dung xiic tdc) vd voi rieng xiic tac RB khong dem lai hieu qud khdng nam muc ndu C. puteana ro ret (Hinh 04).
• Vin bi^n linh DVdndAi chO-ng
Hinh 04. Ty If tSn hao khoi lirgng cua vdn mong doi chimg vd bien dnh sau 8 tuSn u voi n^mmtfcn&uC puteana
Trong qua trinh u g6 trong ndm muc, nuac sinh ra do su phdn huy cua cdc thanh phdn polysacarit ciia vdch tl bao go, hon thi niia, go bi phd huy hiit nuoc rat nhanh nen do im ciia man van mong tang len dang kl (Suttie et al., 1998). Do thi 6 Hmh 05 chi ro do im sau 8 man u vol nim C puteana cda vdn mong biln tinh viW NMM-1 tang khi ham lupng kho cua dung dich NMM-1 gidm tu 20-5%. Trai lai, do dm cua van mdng biln tinh vcri mNMM-2 (xiic tac RB) da khdrig khdc nhau dang kl so voi
van d5i chiing, mjc di t^ 1$ tin hao khIi lupng do nam muc ciia cdc lo^ vdn biln tinh nay thip hon so vdri vdn dii chung. Do do, kha ndng khang nam ciia vdn mong dupe xii 1^
biln tinh vdi hda chit inNMM-2 (xiic tdc RB) cd thi khdng phdi xuit phat duy nhat tir tinh ky nude ciia vdn mdng. Kit qud tucmg tu ciing dupe tim thiy vdi hda chit mNMM-2 (xiic tdc RB) khi sii dung d hdm lupng cao hon cho mau gd Thdng vd Beech (Nguyen et al., 2007).
T ^ CHi KHOA HQC VA CONG NGHf LAM NGHIEP SO 4-2013 71
i'Ong nghiep iting
•tJM-- • ^ 1^ yt B
• V&I biln tf nh O Vin e6i chCmg
Hinh 05. Bp am cda vdn mdng d6i chdmg vd bien tinh sau 8 tuan u vdi ndm mttc nau C. puteana
Ty Id tdn hao khdi lugng cua m l u vdn ddi chiing u vdi nam muc trdng T. versicolor nhin chung cao hon u vdi nam muc nau C puteana.
Vdn mdng xii ly vdi NMM-1 vd niNMM-2 cd kha ndng khdng ndm muc trdng T. versicolor tdt, ngay ca khi dugc su dung d ham lugng khd
thip (5%). Hda chdt mNMM-2 (khdng dung vdi xuc tac) hoac chat xuc tdc RB khi su dung ri£ng biet cung dem lai hieu qua khdng ndm muc trdng T. versicolor tucmg ddi tdt cho vdn mdng (Hinh 06).
" 60 o E so S
f «
1»
.c
•p 10
^
•—
1
•
—-
"T
•
-
—1
mNhM-210%, m ^ M ^ 2 5%. mNhM-2 (RB3.e%) {RB19%) 10%
a Van doi chu-r^
Hinh 06. Ty li tdn hao khdi lugmg cda vdn mong doi chimg vd bien tinh sau 8 tudn u vdi nam mtfc trdng T. versicolor
Do thi binh 07 da chi ra do dm cua vdn van mdng doi chiing sau 8 tudn li vdi ndm myc mdng b i l n tinh vdi cdc cap ham lugng khd cua trdng T. versicolor.
hda chat khac nhau deu thdp hon d0 dm cua
72 T A P c m K H O A H Q C VA CONG NGHfi L A M N G H I E P S 6 4 - 2013
t^tmg ngntep rung
D&chi>ng mNMv^210%, mNhM-35%. mNMM-2 (RB3 8%) (RBig%) 10%
• Vin bien tinh • Vdn J 6 l c h ^ g
Hlnli 07. Bd am cia vdn mong Ml chimg va biln tinh sau 8 tuan 6 v&i itim mfic tring T. versicolor
Nhi6u nghidn ciiu trSn mau go nguyen dd chi ra rdng khd ndng khang n i m muc ciia gd biln tmh vdi NMM-1 xuit phdt ttr khd ndng h ^ chi dm trong vdch t l bdo go (Lukowsky et al., 1999; Rapp vd Peek, 1996; Van Acker et al., 1999). Cac phan tii NMM-1 cd khd nang di chuyen vd tich tu ciia trong vach t l bao, chilm mpt phan khdng gian trong vdch t l bdo gd, da ldm gidm khd nang chiia Im trong vach t l bdo, dieu ndy dupe phdn dnh bdi dd dm thdng bdng ciia mau go biln tinh ludn thip hon so vdi mdu g§ doi chiing. Dd i m trong vdch t l bdo gd biln tinh vdi NMM-1 khdng du d l cung cdp cho su xam nhdp vd phdt triln manh me cua n i m do dd ldm gidm khd ndng phd hdy vdch t l bao cua cac loai nam m\ic.
Dp Im trong vdch t l bao cua mdu gd biln tinh vdi mNMM-2 chi gidm nh? so vdi m l u go doi chiing do kich thudc ciia cdc hjt niNMM-2 ldn hon NMM-1, chi mdt lupng nhd mNMM-2 cd thi di chuyln vdo trong vdch t l bdo, cdn Iji tich tu trong rapt va cdc khoang tring gitta cdc t l bao gd. Cho d i n nay, co chi khang n i m muc ciia go biln tmh vdi hda chit mNMM-2 vln chua dupe lam sang td, n g o ^ trir su giam nhe
cua dd I m trong vdch t l bdo g5 (Nguyen el al., 2007).
3.2. Kha nang khdng n i m biln miiu A pullulans
Sau 8 tuan u trong n i m biln mdu A.
pullulans, mat trdn cua vdn mdng, noi djt bdo tu n i m , cd vet biln mau (mdu den) lan rpng, trong khi do d mat dudi ciia van mdng ty 1?
biln mdu it hon hdn. K i t qud nghien cihi cho thay, vdi vdn mdng ddi chiing, mat tren co mile dd n i m biln mau lan rpng, tii 4,5-5,0, cdn mat dudi cd miic dp n i m biln mau thip hon hdn tir 1,6-3,6 (bang 3). Vdi cac hdm lupng hda chit khdc nhau, miic dp n i m biln mdu d mdt trgn cua vdn mdng biln tinh ndm trong khoang tir 0-1, trong khi dd mat dudi ciia vdn mdng biln tinh hodn todn khdng bi biln mdu bdi ndm. l ^ u v | y , vdn mdng xu ly biln tinh vdi hda chit NMM-1 va mNMM-2 (cd vd khdng cd xiic tac RB) cd khd ndng httu hiju ngdn cdn su biln mdu ciia n i m A. pullulans.
Van mong xii 1^ ridng vdi xiic tdc RB cd khd ndng ngan cdn sgr biln mdu cua nim A. pullulans a miic dp vira phdi
TAP CHi KHOA HOC VA C 6 N G N G H ? LAM NGHIEP S 6 4 - 2013 73
i^ong ngniep ritng Bang03.£><inA;
Chemicals NMM-1 (20%) NMM-1 (10%) NMM-1 (5%) mNMM-2 (10%), (RB 3,8%)
mNMM-2 (5%), (RB 1,9%) mNMM-2 (10%)
RB (3,8%)
gid mire dp Itm rpng cua nam bien mau tren ca hai mgt i m3u vdn do 1/ chimg vd bien tinh
Mdt dudi Van bien tinh
0,0 ±0,0 0,0 ±0,0 0,0 ±0,0
0,0 ± 0,0 0,0 ± 0,0 0,0 ± 0,0 0,0 ±0,0
Vdn doi chirng 1,6 ±0,7 2,2 ±0,8 2,1 ± 0,9 2,6 ±0,5 3,1 ±1,0 1,6 ±0,5 2,3 ± 0,8
cda
Mat tren Van bien tinh
1,0 ±0,0 1,0 ±0,0 1,0 ±0,0 0,5 ± 0,5 0,8 ±0,4 1,0 ±0,0 2,0 ±0,0
Van doi chiing 5,0 ±0,0 5,0 ± 0,0 5,0 ±0,0 4,6 ±0,8 4,5 ± 0,8 5,0 ±0,0 4,8 ± 0,4 Khd nang ngan can sir lan rOng ciia ndm
A. pullulans tren mdu van biSn tinh vdi N-methylol melamine cd the dugc gidi thich do su tich tu cua cac hda chat trong c4u tnic gS (rudt, vdch te bao, tia g§, ...) ldm cdn trd sit xam nh|lp vd phdt trien cua cac sgi nam; m|t khac dnh hudng cua chat xiic tdc RB la mgt mudi nhdm khi sii dung ciiag vdi hda chat mNMM-2 hoac rieng biet cung gay dnh hudng khdng tot den su phat triln cua nam (Nguyen era/., 2007).
IV. KET LUAN
Viec ngam nude de loai bd cdc chat chi6t suat tan trong nude lanh va cac hda chdt d§ bi rCra trdi trudc khi tien hanh thi nghiem kiem tra khd ndng khdng ndm cila van mdng (theo tiSu chudn EN 84) la cdn thilt, dilu nay trdnh dugc nhung sai sdt khi so sanh ty le tdn hao khoi lugng giiJa cdc man van bien tinh vd ddi chiing.
Kit qud nghien ciiu cho thay kha nang khdng nam h&u hieu ciia van mdng go Beech (Fagus sylvatica) khi biln tinh vdi hai hgp chdt cua N-methylol melamine d cdc ham lugng khd cua hda chdt tu 5-20%, Ngoai ra, khi ham lugng khd cua hda chat tang, ty 1? tdn hao khdi lugng cua van mdng do su phd huy cua nam muc (T. versicolor va C. puteana) cd xu hudng gidm, cdn miic do biln mdu do ndm A.
pullulans cua van mdng bien tinh khdng chiu dnh hudng nhieu ciia hdm lugng khd cua hda chat. Vdn mdng xii ly bien tinh vdi hda chdt mNMM-2 (khdng diing chdt xiic tdc RB) hodc
vdi rieng chat xiic tac RB khdng dem lai khd ndng khdng nim muc nau C puteana, nhung cd khd ndng khang nam muc trdng T. versicolor va ndm bien mau^. pullulans.
TAI LIEU THAM KHAO
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decay, pests and protection. Chapman & Hall, London, 3. Haygreen, J.G. and Bowyer, J.L. (2003). Forest products and wood science-an introduction. IOWA state university press.
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i^ong nyiiiep luiig
R.J. (1998). "Chemically modified solid wood - I, Rosenheim, Germany, Document No: IRG/WP Resistance to fungal attack". Material und Organismen, 99-30206.
32(3): 159-182. 12. Wepner, F., Krause, A., and Militz, H. (2007).
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FUNGAL RESISTANCE OF BEECH VENEER TREATED WITH N-METHYLOL MELAMINE COMPOUNDS Trinh Hien Mai
SUMMARY
Wood preservation and wood modification have significantly improved biological durability and prolonged the service life of wood. Several studies have showed that melamine resin modified wood can be improved the decay, staining fungi, and weathering resistance. This paper presents the fungal inhibition of Beech (Fagus sylvatica) veneer modified with two N-methylol melamine compounds against white rot, brown rot and blue stain. The results showed that the veneer treated with NMM-1 and mNMM-2 (with catalyst RB) brought about significant inhibition of fungal decay and fungal staining attack due to the reduction of moisture content in the cell wall to different levels. After 8 weeks of incubation of the veneers with the decay fimgi T. versicolor and C. puteana according to the EN 113, the weight losses tended to be reduced with increasing concentrations of the chemicals in ibe treated veneers. The veneer treated with NMM-1 and mNMM-2 (catalyst RB) revealed high effecriveness against blue stain fimgus A. pullulans at all applied concentrations. The veneers treated with 10% solid content mNMM-2 (without catalyst RB) and sole catalyst RB did not induce protection against C puteana, but showed a medium effect to T. versicolor. However, the combination with catalyst RB, an aluminum salt, enhanced not only the fimgai decay resistance but also the protection against fungal staining for the mNMM-2 treated veneers.
Keywords; Beech, decay fungi, N-methylol melamine, staining fungi, veneer
Ngudi phdn bien: PGS.TS. Ph^m Van Chuwng Ngay nhgn bdi: 26/6/2013
Ngdy phdn bi$n: 24/7/2013 Ngay qttyit djnh ddng: 10/12/2013
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