Letno poročilo 2005

Laboratorij za polimerno kemijo in tehnologijo
Laboratory for Polymer Chemistry and Technology
Urejenost je najve~ja pri nizkomolekularni
frakciji poliestra, ki ima odprto strukturo in
najni`jo stopnjo razvejanja.
- Raziskave molekulske dinamike linearnega in
visoko razvejenega poliuretana ter njunih
me{anic z dielektri~no spektroskopijo in
dinami~no mehansko analizo so pokazale, da
pri molekulski dinamiki me{anic prevladuje
prispevek linearnega poliuretana, medtem ko
razvejeni poliuretan vpliva le na primarno
relaksacijo, ki je povezana s temperaturo
steklastega prehoda pri vi{ji temperaturi.
- Biorazgradljivim amfifilnim kopolimerom
poli(sukcinimid-ko-laktid), PSL, z razli~no
kemijsko sestavo smo dolo~ili relativna in
absolutna povpre~ja molskih mas ter njihovo
porazdelitev. Po dostopnih literaturnih
podatkih je to prva analiza PSL kopolimerov
z absolutno metodo SEC-MALS. Velike razlike
med absolutnimi in relativnimi povpre~ji
molskih mas smo pojasnili z razlikami v
kemijski sestavi kopolimerov in PS standardov
ter z bolj kompaktno konformacijo PSL
kopolimerov v topilu zaradi razvejanja in
zaradi intramolekularnih hidrofobnih interakcij
med laktidnimi enotami.
- Na podro~ju polimerov iz obnovljivih surovin
smo nadaljevali raziskave uteko~injanja lesa
in njegove uporabe za sintezo nasi~enih in
nenasi~enih poliestrov. Les nativnih listavcev
smo uteko~inili z razli~nimi glikoli z uporabo
kislinskega katalizatorja, pri ~emer se je
uteko~inilo do 95% lesa. [e bolj{i izkoristek
smo dosegli z uporabo mikrovalov, kot vira
termi~ne energije. Uteko~injen les smo
uporabili za sintezo poliestrov z vklju~enimi
razgradnimi produkti lesnih komponent.
Nasi~en poliester smo uporabili za sintezo
trde poliuretanske pene. Rezultate raziskav
smo patentirali v treh slovenskih patentih.
- Sklenili smo raziskave molekulske dinamike
delno prepletenih polimernih mre` in me{anic
iz funkcionaliziranih poliuretanov in polimetakrilatov
z elektronsko spinsko resonanco
(metoda spinskega ozna~evalca) in potrdili
98
The ordering of the structure is highest in
the case of low molar mass fraction of polyester,
which has an open structure and the
lowest degree of branching.
- The molecular dynamics of blends of linear
and hyperbranched polyurethanes (HB PU) is
dominated by the relaxation phenomena of
the linear component, which prevails over the
secondary relaxations of the HB PU. The HB
component influences the molecular dynamics
of blends only in the case of the α-process
connected with the high-temperature T g ,
which appears between T g temperatures characteristic
of the pure components.
- We determined relative and absolute molar
mass averages (MMA) and distributions
(MMD) of the synthesized biodegradable
amphiphilic copolymers poly(succinimide-colactide)s,
PSL, with different chemical composition.
According to the literature this is
the first analysis of PSL copolymers by using
the absolute technique SEC-MALS (size exclusion
chromatography coupled to multiangle
light scattering photometer). Large differences
betweeen relative and absolute
MMA were ascribed to the difference in copolymer
and polystyrene composition and to
a very compact conformation of PSL in solution
due to branching and intramolecular
hydrophobic interections.
- In the use of renewble resources for polymer
production we continued with research on
wood liqefaction and its use in the synthesis
of saturated and unsaturated polyesters.
Native hardwoods were liquefied with the use
of various glycols and organic acid catalyst.
Liquefaction of up to 95% was achieved. By
using microwaves as the heating source we
have achieved almost 100% liquefaction.
Liquefied wood was then used as the
feedstock for synthesis of polyesters that contained
incorporated degradation products of
wood components. Saturated polyesters
were used for synthesis of hard polyurethane
foams. Results are protected by three
slovenian patent rights.