Salami pattern formation during phase separation induced by polymerization of 2-chlorostyrene in the presence of polystyrene

Composition dependence of polymerization-induced phase separation of 2-chlorostyrene/polystyrene mixtures

“…These droplets continued to grow or coalesced into continuous domains depending on temperature. At higher compositions just below the threshold ðu ø 0:70Þ above which phase separation did not occur, salami structure similar to those observed in highimpact polystyrene (HIPS) formed [14]. It has been reported that grafting reaction of polystyrene radicals to double bonds of polybutadiene plays a crucial role in formation of salami structure in HIPS [15].…”

“…In this case, initial morphological structure of phase-separated domains can be explained by a geometrical consideration of the phase diagram of the ternary mixture 2CLS/P2CLS/PS that is schematically illustrated in Fig. 7 [11,14]. Since the life time of a radical can be neglected in the time scale of our observation of phase separation, the proceeding of polymerization corresponds to the increase of number of product polymers.…”

Crystal-like pattern formation in polymerization-induced phase separation

“…Figure 1 shows morphological structures, observed with a phase contrast microscope, of mixtures quenched to room temperature after the mixtures were kept at temperature T = 100°C for the indicated duration of time t. At t =4 h, it was seen that a demixed phase formed spherical domains (droplets). It was noticeable that these droplets showed quite narrow size distribution compared with those generally observed in polymerization-induced phase separation [1,7]. At t = 8 h, there appeared regions in which droplets formed a regular array like a crystal.…”

“…In phase separation induced by polymerization reaction or crosslinking reaction, several interesting patterns have been reported as well [1][2][3][4][5][6][7]. Marked examples are the concentric pattern appearing in phase separation induced by photocrosslinking of random copolymer poly(styrene-cochloromethylstyrene) in the presence of poly(vinylmethylether) [3,4], and the salami pattern appearing in high-impact polystyrene [5,6] or in radical polymerization of 2-chlorostyrene in the presence of polystyrene [7]. In this paper, we reported a unique structure formed during phase separation induced by radical polymerization of 4-chlorostyrene monomer in the presence of random copolymer poly(dimethylsiloxane-co-diphenylsiloxane).…”

Mechanical properties of photoaged in situ polymerized PS/EPDM blends

“…6 Exposure to sunlight causes a drastic drop in impact resistance attributed to the photooxidation of the unsaturated rubber phase induced by UV radiation, limiting the lifetime of molded parts in outdoor applications. 4,7 To overcome this problem, it has been suggested that PB be replaced in the polymer composition by a saturated rubber such as poly(ethylene-co-propylene-co-2-ethylidene-5-norbornene), EPDM. 8 Aging of polymeric materials may be defined as a progressive deterioration of the physical properties because of the action of heat, oxygen, UV radiation, or mechanical work, either separately or in combination.…”