Thermal and rheological behavior of reactive blends from metallocene olefin elastomers and polypropylene

Abstract

Reactive blends of metallocene polyolefin elastomers (POE)/polypropylene (PP) with 60/40 composition were prepared with an organic peroxide, 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane, and a bis-azide derivative, diphenyloxid-4,4'-bis(sulfonylazide) (BSA). Ethylene-1-butene (EB) and ethylene-1-octene (EO) copolymers and elastomeric polypropylene (ePP) were used as the elastomeric phase. The effect of elastomeric phase on the thermal, rheological, morphological and mechanical properties of the thermoplastic vulcanizates (TPVs) or dynamic vulcanizates were studied. All TPVs depicted pseudoplastic behavior and blends cured with azide curative showed higher viscosities. The TPVs showed both dispersed and continuous phase morphology that depends on the elastomeric phase type revealing a limited degree of compatibility between PP and the elastomers EO or EB. On the other hand, the TPV PP/ePP showed a uniform morphology suggesting an improved compatibility. Substantial changes observed in physical properties were explained on the basis of blends' morphology and dynamic vulcanization. The results confirm that the mechanical properties are more influenced by the elastomeric phase than by the curative agent. This study revealed a broad new range of opportunities for POE-based TPVs.

Blends of ground tire rubber devulcanized by microwaves/HDPE - Part B: influence of clay addition

“…HDPE crystallinity was more sensitive to differences in the flow of GTR generated by its exposure to microwaves than by the clay addition, as consequence of changes in the number and average size of spherulites induced by the presence of rubber domains [59] .…”

Tuning the mechanical and thermomechanical properties through the combined effect of crosslinking and annealing in poly(lactic acid)/acrylonitrile‐EPDM‐styrene blends

“…The crosslinking process between PLA and AES using 0.8 phr of DCP promoted an efficient molecular entanglement, resulting in a good stress transfer between phases. The impact strength of the PLA/AES/DCP blend (0.8 phr) outperforms commercial high‐impact polystyrene (100–120 J/m) used to produce refrigerator cabinets, electrical and electronic appliances, vehicle parts, air conditioning grilles, shoe heels, toys, furniture accessories, shock protection packaging, and household utilities 80,81 . It also exceeds the results of engineering blends such as PA6/ABS/MMA‐MA (93–117 J/m) 82 and PA6/AES (60–70 J/m) 83 .…”