A s t udyont her mals t abi l i t yofni t r oc el l ul oS e

Ar ti cl e l

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A s t udyont her mals t abi l i t yofni t r oc el l ul oS e

Yas uka2 1 uKUMI TA' , Yu j iWADA● ̀ , Mi t s ur uARAr, andMa8 8mi t s uTM URA●

A8af undame nt als t ud yf o rs pont ane ousI gni t i onorni L r i ce 8 t e r 8 ,t he r malde g r adat i onpr o c e s s ofni t r oc e l l ul os e( abbr e vi at edasNC,he r e af t e r )ander r e c to fs t abi l i z e rwer ee x ami ne d.

Ther es ul t so rF TI RAnal ys i s0fNCandt hataf t erhav i ngbe e nhe at e d8 ug ge S t e dt hathydr o x yl , hydr o per o xi de,andc ar bonylgr oupsg ener at e d,S i m i l art ot het her malde gr adat i ono fus ual p o l yme r s . Andt ot a lc al o r i f i cval ueo rde c ompo s i t i onr e ac t i onde c r eas e d, AC C O r di ngt ot her es ul t s o fSC‑ DSC( Se al edCel l‑Di f f e r ent i alSc anni ngCal o r i met r y) . Ther e s ul t sal s oB ugge 8 t e dt hat de c ompo s i t i o nt empe r at ur ebe c amel o we r , 8 0NChadt ur ne dt obeat he r mal l yuns t ab l es ubs t anc e.

Ont heot herhand,al i t t l eamountOrdi phenyl ami ne( abbr evi at edA8DPA,he r eaf t e r )adde d asa . s t abi l i z e rr e duc e dt hes eC hang e s .

1 . l n tr oduGti on

Ac c i dent alex pl o s i onorf i r e ,whi c hi sc aus e dby ni t r i ce s t e r s , hasb e enr e por t e dr e p e at e dl yi nmany ye ar s . Ni t r i ce s t e r sar ekno wnt oha vet hepr o pe r t y o fs po nt ane o usi gni t i on. Thi spr ope r t yi st hought t obr i ngdo wnt he s eac c i de nt s .But ,t heme c hani s m o fs pont ane o usi gni t i oni snotf ul l yunde r s t o o d. To e s t abl i s hs af e t ypr o c e s so rr e v ie wt o day' smet ho d t oe s t i mat et hes t abi l i t yo fe x pl os i v es , whi c hc ome i nn i t r i ce s t e r S , f undament als t udyons po nt ane o us I g ni t i o ni sne e de d.

I ti sknownexpe r i ment al l yt hatS pont ane ous i gni t i o ni shappene dmor ee as i l yaf t erl ong･ t e r m pr es e r vat i on.So,t r ac l ngt hec hangeo rpr oper t y w

it ht i mei sve r yI mpo r t ant .Thec onc eptort hi s st udywast hatdegr adat i oni Sr el at edwi t h spont aneousi gni t i on.To makec] e8rt he phe no menao fde gr adat i onwo ul dl e adt ot hebas i s

Re c e i v e d: Ma y1 7 , 2 0 0 2 Ac c e pt e d: De c e mbe r1 7 , 2 0 0 2

' Th eUni v e r s i t yo nbk y o . 7 ･ 3 ･ 1Ho ng o , Bl l nk y o･ k u . To ky o1 1 3 ･ 0 0 3 3 . JAP AN

Te l e phon enumb e r : +8) ･ 3 ･ 5 8 I I I ･ 7 2 9 3 E･ ma i lkumi t a @e xp l o s i o n. t . u･ t o k y o . a c . j p ' ' I ns t i t ut ef orGe o ･ Re s o ur c c sa ndEnv i r o nme nt ,

AI Sr r ,

] 6 ･ 10no g a wa, Ts ukub a3 0 5 ･ 8 5 6 9 , J AP AN Te l e ph o nenumb e r : +81 ･ 2 9 8 ･ 61 ･ 8 8 3 7 E‑ ma i l yu j i . wa da @ai s t . g o . j p To pi c :) )Ene r g e t i cMat e r i al s

orunder s t andi ngorB pOnt ane Ou白1 gni t i o n,and f i nal l yt os ugges t i onofes t abl i s hmentofs af et y pr oc es s0rhandl i ng,wt l i chhas8 C i ent i f i cbac k･

bor n.

I npr evi ouRS t udi es0ndegr adat i onofni t r i c e s t e r , e8 t e rhydr o l yB i sw88t houg htt obet hema in c aus e.But ,t hec ondi t i ono rs t at eo fS ampl ewas not8 0C aut i oned,Andi ti SS us pende dt hates t er hydr ol y8 i 8happense v eni rt heni t r ice s t e ri sdr y.

Ont heot herhand,g e ne r at e dgas e s( NOB 0rNO) ar et houghtt obet hec aus eOfde g r adat i on.But , r epor t e de xampl e s0rt he s epr o duc t sar eVe r yf e w , andt hec hang e sofS t r uc t ur eO rpr ope r t i e sar eno t f ul l yunde r s t o o d.

2 .Ex peri mental

2.1Sa mpl epr epar ati onan dap par at us

I nt hi ss t udy .ni t r o c e l l ul o 8 e( abbr e vi at e daSNC , he r e af t e r )仏l dr i c h; ni t r o g enwe i ght1 2 %)wasus e d aSt ypl C t I ]ni t r i ceSt er ,anddi phenyl ami ne ( a bbr e vi f l t e dt I 8DP A, he r e af t e r )仏l dr i c h)wasus e d

ワ

◎ ^{/ " ＼} Q

Fi g.1St r uc t ur eorDPA

Ka y a k uGa k k a i s h LVo l . 6 3 ,No . 5 ,2 0 0 2 ‑2 7J‑

Fi g. 2R

ADEXappar at us ast ypi c als t ab

i l i 2 ; e r . NCwa白 dri edinvacuu m･drierat

3 0 3 K Cal or i r l C val ueo fNCi nt hi ss t ag ewasAb out3 0 0 0

･ 33 O OJ / g . l fc al or i f i cva一 uewaso utoft hi sr ange.t he

NC wasnot

us e d.

Heatwasappl i e dbyRAD

EXappar at us( SyS t t l g Co. ,

Lt d) .Hol di ngt emperat ur ew88Sett O i s ot he

r mal .Too bs e r veC hang esof8 8mpl e,FTI R･

81 00( Sh

i ma血uCo. , Lt d)andDSC･ 20( Met t J er Tbl e do )wer e

us ed.I nFTI R,l i qui dpar af f i nw88 adopt ed.I nSC

I DSC,sampl emaS SWasabout 0. 5mg,t emper at ur er angeWas333‑

523K.F L nd heat i ngr at ewas5K/ mi n.l nt hi sS

t udy ,TAwas us e dasabar ome t e ro fde c o mpo s i t i o nt e

mpe r at ur e . T点me anSt het emper at ur eatwhi c hDSCc u

r ve ar i s i ng.

2, 2He a t degr adati onex peri men ts

NCwashe at e dbyRADEX,andt hec hang e sor s t r uc t ur eo rpr op e r t i e swe r eo bs e r v e db yFTI Ra

nd SC‑ DSC.Hol di ngt emper at ur ewas393K and 41 3 K,

andhol di ngt i mewas4 8 0mi n. Amountor NCwas

l O Omgf わre ac hr un.

2. 3Ex peri mentsa bout st

abHi zer

NCwi t hDPAwasheat edbyRADEX.A一 t er he at e d,

t hec hangeswe r ee x ami ne dbyF TT Rand SCI DSCl i ke

wi s e .Ho l di ngt empe r ahl r eWas3 7 3 K , andhol di ngt i

mewas1 200mi neac h. Amountor NCwasl OOmg,and

amountorI ) PAwa80.1 ,5, l ong.

3 .Res ul tsandd

i s cussi on

3. A比e 1T her rheathadbeenappl ma一degr a datL . OnOfNC i e d, c ol o ro rNCc hang e d.

L三

.e

LLE

芸

胡｢ 1 1 … 2 0 00 1 5 8 0 1 0 8 0 5 0 0

○ } t ) T I t l t n L I P J

I Fi g. 3FTI H e J C l t RS e ● N HL dN C l l pe C ○ 8 ○ c

T a bl eIRe s ul t sofe xper i me nt sofs t abi l i z e r An 1 0unt Co t o r Newl y T巾 Q

T ) 肝

o rDPA Ⅰ R‑ Pe ak l ℃1

l J g' ● 】 Omg ye Li l ght l o w

○ 1 30 1 800 1mg g Fer r n

e en × 1 65 3000 5m

g Gr e e n × 1 40 27 00 l ong D

e e p

" g r ̲ 9 9 ̲ P , A ^× 1 40 2900

肝 IIDOO2000

1SOO 1

0 0 0 ^{5 0 0}

O D u t T I I P8

L J C ･ l

I

P

Fi g. 5FTI A RS pe c t r umOfDPA 48m2000 1 S O B I Q O O S O B

0 0 L J q I

! u 一 岳 J

l Fi g . 6 F r I ■ mA Rs O P N A C 1 1 0 喝 pe n E c t r aofNC,NCw it hDP

A

‑

t D , A的 ∧

D P A l m g ＼p P A 5 l 曙 ＼D P

8 0 1 2 8 1 6 0

2 0

S 叩I eT e E Pe r 8 t U r e

( tI

Fi g. 7SCI DSCc ur v e s0 rNCwi t hI ) PA r ang

e,S oni t r i ces t eri st heke yofexot her mal pr o pe r t y .Fr omt he s er e s ul t s ,i tc o ul dbes ai dt hat

ni Ka t r y i ce a k uGa s t e rg k k a r i oupwo s h i .Vol u ldbel . 6 3 .No . e 5 s .2 s enbyhe 0 0 2 a t . ‑ ‑2/ . 3‑ 3. 2Ef T f e ctofDP AonNCdegr adati on her e s ul t sWer eShowni nTabl e1 .Th

ec ol or , l R･ A Pe ak. T｡ .andQD 9 CWe r el i 8 t e d.

f t erNCw it hDPAwashe at e d,t hec ol o rofi t hadbeenchangeddramat i c F L l l y .Whi t e

powder c h氏ng edt ogr e eno rde e p･ gr e enone.

Aboutt heFTI RS pec t r a,t henewl ypeakwas no

tr oundwhe nNCwasheat edwi t hDPA( Fi g. 5

6 ) .Peak

ofi two ul dbes e enaBt headdi t i o no ft hat orNCandDPA.But .pe akofDPAi ss omany

t hat newl ype akmi ghtb ehi °e dAmongt hem.

Byaddi ngDP^t oNC,t hede c ompos i t i o no fNC byheat

Waspr e vent ed( Fi g. 7 ) .QD . S . : Ofhe at e dNC wi t , hDPAwer eal mo8 t . t heS ameaSNCwi t

hout heat i 叩 . ToNC I OOmg,onl yl mgofDPAwa8 e r r ec

t i vei nt hi sC Ondi t i on.But ,muc hamo untof DPAt ur ne dt oar l e c tt heDSCc ur ve.I tS ug ge 8 t e d t hatDP^ mi ghtr e actWi t hNC ( orgener at ed g n S B e S ) . T

bt al c al o r i r ] cv al ue8 e eme dt obede c r e as e d w

hen5mgorDPAwa8adde d,buti twoul dbet he e r r orormeasurementOf88mpl emas s .Thewayo f adopt i ngo rb88 el i nem i g htbet

hec au8 e.

3. 3D The egr adati onmechani s mofNC

r e 8 ul t 80rF TI R8 ugg e S t e dt hatde g r adat i o n o

fNCwasS i mi l art ot hatofot herpol ymer s.

Ther e f or e,i nc ons i de r ingdeg r adat i onme c hani s m , c ommonl yknownr eact i onswer eadopt e d,l i ke

" hydr ogendr awi ng･ out ' ' ,and" aut O1 0Xi dat i on"

. Exper i ment al l yobs er vedgr oupsWer et O

be gener at e dandt akeni nt oac c ountC h

i e ny . イン N O2 ‑R

十

‑ 0 ･+ RTI ‑ R ‑ O H + NO2 R' ･ ' ･ +02

一 ^{･ ･ R' i O l 〇 ･}

R Lo一 〇 ･ 耳■

･十R Tト ー ーR 伽 H+良"

一

R

6.

‑ R

+ 良" ･

凸 3 ◎ 8 細 ^⑳

R

R'

･

R

( 6 )

' く ) ･ ･ ^〇･十R ' ･‑ ‑

R' i CI OR"

2R

‑ R' く: く)+02十 R

Thi SmeC hE L ni S m woul dnotc onf l i c twi t ht he me c hani s mWhi c hhadbe en8 ug ge S t e db yK imur a etal . Ra di c al r e a c t i o ni BVe r yC Ompl i c at e dandt he r e mi g htb emanyO t he rwa y8 ,butt hi ss c hemewo ul d bet heSi mpl eande88 ent i alonef ormaki ng pr o duc t s .

I nt hi s8 t ud y ,t hee f f e c tofN O 2 WASno tS t udi ed.

But ,888 0mer es e ar c her shad8 uggeS t ed,N O 2

woul dpl ayt hei mpo r t antr ol e.Notonl y

but 8) 8 0N

mi g htbeamai nc aus eO fS uS t ai ni ngau t O‑

oxi d8t i on.Fur t heri nv es t i g at i onaboutt hee f f e c t o ft he s eg a8 8 e 8i 8ne e de d.

4.ConcJ usi ons

l nt hi sS t udy ,de gr adat i ono fNCande f f e c tof DF Awer ee xami ne d.WhenNCwasdet e r i o r at ed b yhe at , ne wg r o ups , Whi c hc o r T eS P Ondt ohy dr o x yl . hydr ope r o x i de , c ar b onylg r o upswer eg e ne r at e di m NC. A L t erde g r adat i on, he atOrde c ompo s i t i o no fNC bySCDSCwa8dec r eas ed,anddec ompos i t i on t emper at ur eWasl o wer e d. W h e ndr ie d･ NCw it ho ut DPA i Bbei ngpr es er ved,t her mal l yuns t abl e 8 ub 8 t an C e . O uc ha8hydr o pe r o x i de , wo ul dha vebe e n

gener at e d.But ,S maI lamountorS t abi l i z e rwas pr ov edt ob ee f r I C i e n t .

Furt heri nvest i gat i onont hepr esumpt i ve me c hani s m woul dl eadt oS ugge8 t i onofS af et y pr o c e

8 ,Whi c hhass c i e nt i f i cbac k･ bor n.

Refer 8nC88

1 )LS. LuB8i er ,H. GagnOn and M. A. Bohn , PT O Pe J J aJ 7 E S ,Ex pJ o s L ' t , e s ,伽 L e c hJ 7 ) ' c s 25

I7

α卯の

2 )a. Ki mu m ,PL ･ O PeJ J anL S.EHP/ oSJ ' t , e S, Pm t e c hJ ) J ' c s J 4,89 ( J 9 8 9 )

3 )Kayaku gakk 8 i , l ̀ Handbookofener get i c mat er i aI 8 ",p. 213･ 219 ( 1999) ,kyor i t su‑

Publ i s hi ng

4 )Hi de akil kada , " RekkanOki 8 0 C hi 8 hi ki " ,p. 65 ‑

7 8( 1 99 4 ) ,Sang yO･ t O8 yO

5 )Ki mur aet . 81 .ka yakugakkaiko ue n･ youB hi 8 yuu, 85( 1 9 95 )

6 ) I Gmu r ae t . 81 ,ka yakug akkaiko uen･ yo uS hi 8 y uu, 63( 1 9 98)

7 )KAWaguChiet Al ,kayakug8kkAikouen･

youS hi 8 yuu,7 3( 2 002 )

‑274‑ 火燕学会誌