Toughening effect of CPE on ASA/SAN binary blends at different temperatures

Abstract

The effect of chlorinated polyethylene (CPE) on the impact toughness of acrylonitrile-styrene-acrylic (ASA) terpolymer/ styrene-acrylonitrile copolymer (SAN) binary blends (25/75, w/w) was systematically investigated at three different temperatures (230 8C, 0 8C, and 23 8C). With the addition of 60 phr CPE, the impact strength increased by 11 times at 23 8C and 10 times at 0 8C. However, the toughening effect was not obvious when the testing temperature was 230 8C. Since the glass-transition temperature (T g ) of CPE was about 218.3 8C as measured with dynamic mechanical analysis tests, the polymeric chains of CPE have been "frozen out" at 230 8C. As a result, CPE evidently cannot improve the toughness of the blend system. The morphology of impactfractured surfaces observed by scanning electron microscopy also confirmed the effect of CPE on the impact toughness of ASA/SAN binary blends. The heat distortion temperature remained almost unchanged, indicating that the improvement in toughness did not sacrifice heat resistance. Furthermore, other mechanical properties were evaluated, and the possible interactions among components of the blends were also analyzed by Fourier transform infrared spectra.

Room temperature and low temperature toughness improvement in SAN/ASA blends by blending with CPE, HNBR, and BR

“…More specifically, the temperatures from T g ,1 to T g ,4 represent the glass‐transition temperatures of BR, PnBA (the core of ASA), CPE (or HNBR), and SAN, respectively. In this study, since the samples tested with DMA were annealed before testing, the T g of SAN (132–136 °C) has increased about 10 °C than the samples which were not annealed . The “cohesional chain entanglement theory” could account for this phenomenon: when the SAN is annealed at about T g , the molecules of SAN tend to entangle and the entanglement points restrict the movement of polymer chains, leading to the glass‐transition peak shifting toward higher temperature.…”

“…Through vertical comparison, the surface roughness of every group is getting increasingly poor with the testing temperature dropping: the impact‐fractured surface is the most rough at room temperature but most smooth at −30 °C. It exhibits a good compatibility among different constituents in C30H0, C15H15, and C0H30, which is consistent with our previous studies . In particular, there is no obvious phase separation in C15H10B5 from 25 to −30 °C, indicating that the five components of blends are compatible.…”

“…Toughness is a key parameter to the performance of polymers in various engineering applications . Generally, temperature is a very important external factor for the impact toughness of polymer materials.…”

“…They have excellent toughening effect in many polymer matrix, such as SAN, nylon, and PVC, etc. In our previous works, the toughening effect of CPE and HNBR in SAN/ASA blends has been studied, respectively. The results showed that they both have high efficiency in toughening SAN/ASA blends at room temperature.…”

Synergistic toughening effect of chlorinated polyethylene and acrylic resin on SAN/ASA blends at low temperature

“…However, the incorporation of ASA fails to offer a satisfactory increase in the toughness of brittle SAN . In our previous work, chlorinated polyethylene (CPE) was used to toughen the SAN/ASA (75/25) binary blends. The addition of CPE was effective in improving the impact toughness of the SAN/ASA (75/25) binary blends at 23 and 0 °C.…”