Naslov
Thermal and mechanical properties of PU/PC blends after UV irradiation

Autori
Govorčin Bajsić, Emi ; Rek, Vesna ; Miličević, Tamara

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Polychar 20 World Forum on Advanced Materials Book of Abstracts / Rogošić, Marko ; Macan, Jelena - Zagreb : Fakultet kemijskog inženjerstva i tehnologije Sveučilišta u Zagrebu, 2012, 287-287

ISBN
978-953-6470-57-0

Skup
POLYCHAR 20 World Forum on Advanced Materials

Mjesto i datum
Dubrovnik, Hrvatska, 26.03.2012. - 30.03.2012

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
polyurethane; polycarbonate; Uv irradiation; thermal properties; mechanical properties

Sažetak
The effect of UV irradiation on the thermal and mechanical properties of PU/PC blends was studied. Poly(ester–urethane) elastomers (PU) based on poly(caprolactone) glycol, PCL, of Mw =1250 as soft segment and an aromatic type of diisocyanate (MDI) as the hard segment were synthesized by a prepolymer procedure. Blends of PU elastomers and polycarbonate (PC) with different weight ratios (70/30 ; 50/50 and 30/70) were prepared using a Brabender mixer. Differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA) and mechanical measurements were performed in order to determine the influence of UV irradiation. Irradiation of the PU/PC blends was carried out using a ultraviolet chamber SUNTEST ( λ= 290 nm), the PU/PC blends were irradiated for 100 and 200h. DMA results indicated partial miscibility of PC with PU with higher hard segment content in the PU/PC blends what was attributed to favorable interactions between ester groups from soft segments and urethane groups from the hard segments. In the blend with 70 wt. % of PC the formation of PU–PC copolymer by –OH of PC and ~NCO groups of PU interchange reaction was observed. From DSC and DMA analysis it was mainly found that thermal properties, in terms of glass transition temperature (Tg) were affected by UV exposure.The photochemical degradation of the polyurethane with an aromatic isocyanate is associated with the scission of the urethane group and photooxidation of the central CH2 group between the aromatic rings. The processes of photooxidative degradation is less pronounced in PU/PC blends with higher hard segment content in polyurethane elastomers.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo

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