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Tacticity
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Semicrystalline polymer
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Size and location of side groups
Polyethylene Polypropylene Poly (methyl methacrylate) Polystyrene
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Macro molecular conformations
(1) (2) (3)
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Tacticity determined conformation
Atactic polypropylene Isotactic polypropylene Atactic polystyrene Syndiotactic polystyrene
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Fringed micelle model (1) (2) Chain folding models (1) (2) (3)
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Properties of bulk semicrystalline polymer
Experimental results indicates crystallite behave like defect resulting in higher values of (1) (2) (3) (4) (5)
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Thermal effects on crystallinity
Tm: Tg: (1) (2) (3) (4)
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Six factors affecting Tg
(1) nf: (2) Secondary forces: (3) Internal mobility: ns n
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Six factors affecting Tg
(4) Chain/backbone Stiffness: (5) Chain length: (6) cross-linking: Poly (diallyl phthalate)
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Phase transition temperatures, Tg & Tm
First order transition Specific volume, n (cm3/g) Second order transition Tg Tm T(°C)
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Differential scanning calorimetry
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