Semicrystalline polymers molecular architecture

Ethylene-styrene interpolymers exhibit a novel balance of properties that are uniquely different from polyethylenes and polystyrenes. In contrast to other ethylene-a-olefin copolymers, ESI display a broad range of material response ranging from semicrystalline, through elastomeric to amorphous. The styrenic functionality and unique molecular architecture of ESI are postulated to be the basis of the versatile material attributes such as processability (shear thinning, melt strength and thermal stability), viscoelastic properties, low-temperature toughness and broad compatibility with other polymers, fillers and low molecular weight materials. 

Similar to many semicrystalline polymers, PLA exhibits both Tg and 7j . The Tg of PLA can range from 35 to 60°C depending on molecular weight, the presence of plasticizers, physical aging, polymer architecture, and degree of crystallinity [14]. Above Tg PLA is rubbery, while below Tg it becomes a glass, but it is still able to creep until it is cooled to its 3 transition temperature at approximately —45°C, below which it behaves like a brittle polymer [15]. In applications where mechanical properties are important, such as packaging... 

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