65TheScienceReportsoftheKanazawaUniversity，Vol.VI，No.2，pp.6
5‑‑‑68，May，1
95900theDielectr
icProperties of Polycapramide
ByMitsuo IDA吋(Receiv
edSeptember22，1958)
1. Introdudion
On thedielectricpropertieso
f polycapramidεFuchino and Okada[l]studied atfrequencieshigherthan 400kcjs，and Kawaguchi[2]at1
00kc
js.Nylon which i
ssimilaron the str
uctureas polycapramide was studied indetail by BakerandY
ager
[3]at
frequencieshigherthan 1kc
js. Th官 present author εxamined polycapr
a凶 de dielec‑hatpolycapramide isanalogousto
tr
i
call
ya
tfr
equencieslowerthan1kcjs，and foundttz.
higheralcohols.
Moreover it was found th呂t polycapramide plac告d b
etween two metali
cplatesofdi
fferent kinds developes an electromotiv
eforcei
nasmilar waya
sthephenomenon
discovered by Takeyama[4] in n‑higheralcohols.
2 Experimentalprocedure恥)(Material
fpolycapramide kindlyo
ffere
d by Toyo RayonCo.wasu
sed.I
tsm.p.
A specimenoisabout2
10"
C and s→αtransitionpointi
sabout150"
C. Forthedielectri
cmeasurements
nthickness werediscsof the material 4.5cm indiameterand2.0m mor4.3m m i
madebymouldingand machining. Thesewerecovered with alminum foils on bothfacesusing vacuumgrease.
(Dielectri
cmeasurem日目的Two sor
tso
fcir
cu
it
s wereused inthepresent experiment. In frequencies higher. Circuit for lowfrequencym回 surement
Fig.1
後PhysicalInstitute，Facu
ltyofScience，KanazawaUniv
ersity66民主. IDA

than500c/s abridgewasused inthesamewayas described i
nthep
r巴v
iou
spaperよ5JForth思 lowerfrequency regio
n weconstruciedaspecialcir
cu
itas shown inFig.1コ
similartothe typedevisεdbyBrown and Ramsay.[6An RC typeoscillator wasusεdforfrequ色ncieshigherthan20c/s，andamotor‑driven
or frequencies of 1c/
sand0.5si
n色 potentiometerwasused f(Measurement of eledromotive force)
1.
4m m，area

巴d b
etweentwo metalic plates(distanc日
The specimen was melt

3cm勺 ofdi
ffer釘 1t kinds and then solidified，and this was placed in aliquidpar
affinb呂thinwhich th告 白 mperatureofthespecimen wasregulated.Theeledromotive forcev
ity.
was measured byapotentiometero
f10'11' sen詰i

3. Experimental問 呂ult
sanddi邑cnssiol
1(Lower temperatureregion)
The frequencydependencyo
fthedielectri
cconstanta
tWC is shown inFig.2.T
hεdispersion 抗 告xtra‑low

呂配ems to be analogous tot
hat discovered in

7I
船主同‑.

\\\~~
A回 Z 包5xlO‑' 1，10‑'
10'A10'号IsFig， 2. Fr告quencyd告pend日ncyo
f thediel記 ctric
constantat8'C¥在ulley，[7J whon‑higher alcoho
13at2
0'
C by Meakins and 1

assuming the presence of hydrogen‑bonded chains of hydro玄the fact bygroups capable ofreversing theirdirections， In polycapramide a1so the orientationofpolar groups
forminghydrogenbonding N‑H，・・・，，0 is probablythe causeo
f thedisper
sioD.
(Higher tθmperature region)
elationof ther
告呂 1partf?
/and thenegativeimaginary parte"of theTh邑 rdielectr
icconst
anta
t1
50'
Ci
3 showni
nF
ig.3.
Thedirect conductanceerrorof，，11，namely the addit
iv
ec
ontr
ibut
iont
o，
，
" fromdc
conductance wascor
recte
dby thesubtr
actionof the dc conductanceGdcfromthet
otalconductanceG(ω) ateach frequency呂sin the previous paper.[8J Thedc conductivityof polycapramid告 wasdetermined by avacuumtubeelectromeie，rThegraph inFig. 3i
s acircu
larar
c withits c告nteral
ittlebelowthe εaXls， At
lower frequencies exp巴rim
創 lt
aler
r
or
sbecame lar
ger andbelow alimiting frequency

O;
zt
ノle.
Dieんctriピ Properties0/Polycapramitie

67εd80~ム一一よ¥

60、、Fig.3. Complex dielectr
icconstan
tof polycapramide
at1
50C
011 couldnotbemeasured. Thevalu
e Gdc fort
hecase(about0.5kc/s) neitherεI norεof Fig.3ammountedt
o5% of thetot
al conductance a
t20kc/sandt
o30% at0.5kcjs.

It was supposed from thepreviouss
tudies[lJ[2J thatadifferentkindo
f dispersionwill happen at frequencies higher than 20 kc/s， but this was not confirmed bymeasurement.
The呂bove‑mentionedphenomenonexhibitedbypolycapramidei
nt
h色 highert
en:1p
eratureregion seemst
obeanalogoustothatfoundby th日 presen
tauthorじ8Jin;z‑higheralcohols.
The anomalous dielectricproperti
eso
f polycapramide and n‑higheralcohol
srnay besimilarlyexplained.
(Electromotive force)
The electr
omotiveforcedeveloped by using

口lV

Au and Ptp
late
sas twoelectr
odεsisshowni
nFig.4 as anexample. As to the polar
ity Au';00ト

告.
i
spositive and Ptis negativ

Thevalueoftheelectromotive forcewasnotnecεssar
ilythe same in ev♀ry case，but was

500ト

初日トgenerally independent ofthetemperatu印 . The呂turedotted curvei
nF
ig. 4 shows the temper

dependencyo
ftheelectri
cconductivitymeasured
byag昌lvanometerbyusingn
icke
lelectrodes.
As t
hee
lect
romot
iv母 forcewas measured bya
potentiomet町

Jtt
F

3日
日ト

J/lE比回e引
刷tnconductlVlt
y200ト，Ft

JJ100ト，，，.d ，JJJJit could not bemeasured whentheelectr
ic conductiv
ityoft
hespecimen waspoor. Buti
tappearedt
hatev
色nattemp訂 以ures
lower than 100'C electromotiv
e for
ce wasdevelopεd. Thepolar
itiesoft
hee
lectr
omot
iv色force developed by using sev
er
al metals ar
e0810

園 出 . . . J

100120140a160180 '0Fig.4. Temperature dependency('f theelectromotiv
eforc
edevelopedin polycapramide by Au and ptplates，and oftheelectr
ic conduc‑tiv
ityM ， IDA

68
shown below.
ーLAuPtAu
NilPtlAg lNi I Ni I ZnNiFrom this we found thatth
epolarities were the same as when water was placed
between theεlectrodesinsteadof polycapramide. Forcomparison wemeasured theelectromotive forcedeveloped

using cetyJalcohol， andolar
ity wa3 t
he same asi
nt
hecasefound th旦tthe po
f polycapramide. For example the temperaturefrom the Eastman Kodak Co. (m.p.48.

80f ~. ~601‑

dependencyo
ftheeledromotive force developed
using PtandNiastwoeledrodesi
3showni
n?nv'0日5図The fluctuation of th
告 合lectromotiv巴 fo工c
e wasconSplCUQUS lnour邑xperiment.

•401‑:.
tlcC廿 C!cunductlvlty

ob‑i‑

20Thought
hemeasurementatthetemperatu町 saboveth
ε m.p. was difficu
lt on account of the poorconductivity，electromotive forceofth
e same orderofmagnitudea
si
nt
h
esoli
dwasa
1sod在t
ect
e
dwhen
th
e specimen was intheliquidst
a問。
Now we suppose that eledromotive force 1S

10304050日Fig.5. Temperaturedependency of theelec‑邑dtromotiveforcedevelopincet
ylalcoho
lbyPtand巴呂Ni platdeveloped by polycaprarnide and cetylalcoholfor a same reason， 1n Takeyama's
Iment[4Jusing Pt andAu as eIetrodes Ptwas po日itiv
eandAu negative and heexpef

concluded thatthernetal witha 1旦rgerwork funct10n showed positiv
epolarity. Buti
nour experim記ntusing Ptand

Auwaspositiv世 andinthatusingAgandNi，Ag

unct
ion.
waspositiv
ethough Ag has a smaller wo工k f
After all，t
h邑

oft
h
eelectromotive force seemedt
obedue tothedifference

ofthei
onization tendencies oft
he two metals with respecttothetr
ac日 ofwatercontain記d i11the sp百cim百五 rather than to the difference of the work
functions. The factthattheelεctromotive forcedevelopedhyεspecimens waslar
ger thanthat

pure sp邑cimensseem to supportthesu
pposition.

lsot
Ir.H. Mitani fo
rthedielectr
i
crne
asur
・ements. Hea
The author is indehted to恥xpressesh
is gratitudetoToyo Rayon Co.for・ thegiftsofpolycaprarnide.

告References
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hpolymers(i旦 Japanese)6(1949)497(1] R O園

. Kawaguchi I
bid，13(1956)283.
(2J TakerandW.A Y
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eakinsandJ. W， M
uiley Aust， J.Sci.R
es， A， !
'(1%1)365(7J R.Ida SdR
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