Investigasi Pengaruh Pluronik 473 Pada Stabilitas Shellac
 
3
2
1
Istiqomah
1
, Khairuddin
2
, Nanik Dwi Nurhayati
Jurusan Fisika FMIPA Universitas Sebelas Maret
Dosen Jurusan Fisika FMIPA Universitas Sebelas Maret
Dosen Jurusan Pendidikan Kimia FKIP Universitas Sebelas Maret
Jl. Ir. Sutami No. 36A, Kentingan, Jebres, Surakarta
 
 
ABSTRACT
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The effect of pluronic 473 on stability of had been investigated in this study. The films were prepared
using solvent casting  method. The shellac stability related to polymerization of shellac molecules
could be identified through insoluble solid test. The polymerization was occured by humidity
atmosphere or by heating.. The insoluble solid test was then performed after the samples were 1).
placed in 85 % relative humidity, 2). heated at 125
0
 C for 10, 30, 60, 90, and 180 minutes, a test called
“life under heat”. The result showed that percentage of insoluble solid by both humidity and heating
treatment increased with increasing of time from 2 % to 5 %, and from 20 to 82 %, respectively. The
addition of pluronic reduced the amount of insulible solid of samples at 85 % RH after 1st and 2nd
month, but no effect of the 3rd month. For the heated samples, the amount of insoluble solid increased
significantly from 10 to 90 minutes, then increased steadly untill 180 minutes.The addition of pluronic
also reduced the insoluble solid. These results suggested that pluronic 473 improved stability of
shellac, altought could not stop the polymerization.
 
Keyword: Shellac, pluronic, insoluble solid testing, polymerization.