Polymer Crystallinity

Overview of the lectures in polymer physics Topics: The amorphous solid ground The crystalline commonwealth thermal transitions and properties Mechanical properties Rubber elasticity Polymer blends and IPNs Polymer composites and nanocomposites Polymer processing and rheology Lecurer: Patric Jannasch land of Chemistry, theatrical role of Polymer & Materials Chemistry patric.jannasch@polymat.lth.se Solid-State Properties Different range of mountains conformations in diametrical phases amorphous Dissordered, mixed state Semi-crystalline partially ordered, partly folded state Increasing crystallinity PS PMMA polyvinyl chloride PE PP p. 153 1  clutch conformations and entropy Which dynamic chain has the in high spiritsest (conformational) entropy, S? a) b) c) S = k lnW d) The Amorphous State Randomly coil interpenetrating irons Entanglements at sufficiently high molecular payload Not all good deal is occupied: simple vo lume concept Diffusion of bittie molecules Segmental and chain mobility strongly dependent on temperature and free volume Amorphous high molar mass polymers brush off be in the glassy state, rubbery state or mellow out state going from low to high temperature spaghetti analogy p.

154 2 Chain Entanglements Sufficiently long molecules Critical molecular weightiness face on chain flexibility Restrict prey Mc particular molecular weight for formation of static entanglements Me molecular weight between entanglements Mc ? 2Me Flexible chains go away high Mc, aromatic main chains give low Mc The molecular weight of commercial polymers importantly a! bove Mc p. 154 Reptation manakin in the melt state How do polymers move in the involved state? possibility of De Gennes long range movements of chains curving motion within a virtual tube frictional resistance by entanglements successful in predicting viscous properties of entangled polymer melts p. 156 3 The methamphetamine hydrochloride Transition Different theories isoviscous state (1012 Pa s) - isofree volume...If you want to mystify a full essay, order it on our website: OrderCustomPaper.com

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