Ten sile Properties The tensile properties of HIPS composites were tested using a Zwick UTM 1445 at a constant temperature of 23 C and the humidity of 50% RH. The gauge length of 25 mm, crosshead speed of 50 mm =min and sample size (7.5 0.5 0.2) cm were used to determine tensile strength and elongation at break (according to ISO 527-1 and ISO 527-2). The results are the average of at least five samples.
RESULTS AND DISCUSSION
Thermal Analysis Results from thermogravimetric analysis of prepared composites are presented on Figs. 1–3, while temperatures of onset, 5% mass loss (T95), temperature of peakdegradat ion (Tmax), degradation rate at Tmax and the residue that remains at 550 C are summarized in Table 2. It is visible that zeolite itself does not have an effect on thermal stability since samples with 2, 4 and 8 mass % of zeolite have T max and maximum degradation rate almost identical to pure HIPS, Table 2. Samples with ammonium polyphosphate (APP) and zeolite have 60–90 C lower T95 value compared to pure