Letno poročilo 2005

Laboratorij za polimerno kemijo in tehnologijo
Laboratory for Polymer Chemistry and Technology
talini z dvopol`nim ekstruderjem ali z
enostopenjsko in situ polimerizacijo. Po
postopku v talini so nastali interkalirani
nanokompoziti z nekaj vi{jo temperaturo
steklastega prehoda od PMMA, termi~na
stabilnost pa je bila izbolj{ana {ele pri
temperaturah nad 300°C. Enostopenjska in
situ polimerizacija je nov postopek priprave
polimernih nanokompozitov, pri katerem
rekcija polimerizacije poteka v topilu etanol/
voda v prisotnosti kvarterne amonijeve soli,
MMT in iniciatorja, po zaklju~eni reakciji pa
polimer oborimo z vodo. Nastanejo interkalirani
nanokompoziti, katerih termi~na
stabilnost je bistveno izbolj{ana v primerjavi
s PMMA. Razvili smo tudi postopek priprave
oksidnih ali kovinskih PMMA nanokompozitov
z redukcijo ali hidrolizo in situ med
polimerizacijo metilmetakrilata v masi.
- Nanokompozite smo pripravili tudi iz
komercialnih vzorcev modificiranega MMT in
naravnega kav~uka. Ugotavljali smo vpliv ~asa
me{anja na vrivanje elastomernih molekul
med plasti MMT ter vpliv MMT na zamre-
`evanje in reolo{ke lastnosti gume. Prisotnost
MMT v gumeni zmesi je pove~ala hitrost
zamre`evanja kav~uka. Nastali so interkalirani
nanokompoziti.
- Za industrijskega partnerja smo na osnovi
recikliranega polietilentereftalata sintetizirali
serijo nenasi~enih poliestrskih smol in
poliestrskih smol kot dodatkov za prepre-
~evanje skr~kov pri zamre`enju nenasi~enih
poliestrskih smol. Dve formulaciji sta bili
izbrani za pilotno sintezo.
SODELOVANJE Z INDUSTRIJSKIMI
IN DRUGIMI PARTNERJI
- Renault, Francija: protonsko prevodne visoko
temperaturne membrane za gorivne celice
(odg. nosilec iz L13)
- Razvojno tehnolo{ki in{titut, Savatech d.o.o.,
Kranj: sodelovanje pri raziskovalnem programu
in projektu na podro~ju elastomernih
nanokompozitov
100
adsorbed on the particle surface protecting
them from oxidation as well as improving
their dispersibility in organic media.
- Nanocomposites of modified montmorillonite
(MMT) and poly(methyl methacrylate)
(PMMA) were prepared by melt intercalation
using twin-screw extruder or by one-step in
situ polymerization. The nanocomposites prepared
by melt intercalation exhibit only a
slightly higher glass transition temperature
(T ) than pure PMMA, whereas the thermal
g
stability was improved at temperatures above
300 °C. One step in situ polymerization is a
novel process for the preparation of nanocomposites.
The polymerization proceeds in
an ethanol/water solvent mixture in the presence
of a quaternary ammonium salt, MMT
and an initiator. Intercalated PMMA nanocomposites
were precipitated in water. Their
thermal stability was greatly improved compared
to PMMA synthesized under the same
conditions. A new method was developed to
prepare PMMA nanocomposites with metallic
or metallic oxide nanoparticles by reduction
or hydrolysis during the in situ bulk polymerization.
- We also prepared intercalated nanocomposites
of natural rubber and commercial
MMT. The influence of mixing time on intercalation
of elastomeric molecules between
the layers of MMT, and the influence of MMT
on crosslinking and rheological properties
were examined. The presence of MMT in rubber
mixture increased crosslinking.
- In cooperation with our industrial partner we
sythesized a series of unsaturated polyester
resins and low-profile additives for polyester
resins based on recycled polyethylene
terephthalate. Two formulations were chosen
for pilot synthesis testing.
COLLABORATION WITH INDUSTRIAL AND
OTHER PARTNERS
- Renault, France: Proton conductive high-temperature
polymer membranes for fuel cells
(principal investigator from L13)