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| CHIM0038-1 | Physics of Polymer Materials | ||||||||
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| Duration : | 18h Th, 24h Pr | ||||||||
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| Holder(s) : | Jean‑Marie Liégeois | ||||||||
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| Course contents : | Description of the molecular structure in organic polymers, the specificity of carbon atom, the importance of the covalent chemical bonding, and their consequences : from random coil model to densely cross linked network topology. The sense of the structural units and their combinations in random, block, and graft copolymers, with given MW distribution, in blends and alloys. Discovery of the reasons for a glass transition using 4 experiments and leading to the free volume concept, molecular motion, deformation, and flow. Analysis of the four regions of the thermomechanical curve. Detailed analysis of the Maxwell model in creep, relaxation, and cyclic loading. Changing from time sweep to temperature sweep experiments leads to the time / frequency -temperature superposition principle. Observation of beta and lower transitions. Usage of WLF equation : illustration with first generation PVC window frames. The theory of rubber elasticity and its usage in studies of cross linked plastics. Illustration with matrix resin of composites and with ground heating pipes. Phenomenological aspects of semi-crystalline -unblended- plastics Conditions and criteria for crystallinity in polymers : thermodynamic, kinetic, and composition effects on melting temperature, maximum possible degree of crystallinity, and actual crystallinity under given conditions. Illustrations with the moulding of PET bottles versus PE moulded cups and PP cast films. Behaviours encompassing also polymer blends, alloys, and filled plastics The assessment of morphology in multiphase polymer materials. The significance of HDT records versus the thermomechanical curve. The description of polymer flow in the melt or liquid region and the derivation of the power law parameters from capillary rheometer measurements. The significance of the MFI value versus the pseudoplastic curve. Shearing effects in the moulding of rubber modified plastics. HS induced molecular orientation. Irreversible deformations and ultimate properties of plastics : shear yielding or crazing in glassy polymers; Saunders experiment; parameters of Sternstein-Onchin envelope. Promoting factors leading to optimized impact modifiers. Applying experimental fracture mechanics to plastics : analysis of transient testing, impact, and fatigue loading. Factors of the ductile brittle transition, temperature effect on impact properties, application of Paris law to fatigue crack propagation. Illustration with HDPE gas pipe predictable lifetime. The significance of the normalized impact test data versus fracture mechanics. Interaction of visible light with multiphase products : the Raleigh diffusion law. Illustrations with transparent PC baby bottle, glass reinforced polyester, PET soft drinks, rubber modified PVC, PE blown film, versus opaque HDPE cans, HIPS, ... and compared with milky PP syringe or milky PET student beer cup. Permeability and diffusion in polymers : Intrinsic properties of a given polymer, problem resolution through multilayer extrusion moulding or with nano layered additives. Illustration with snacks packaging, blood plasma conservation, gasoline tanks for cars, and the more recent plastic JUPILER beer bottle. | ||||||||
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| Course objective : | The course intends to provide the student with a good understanding of the physical behaviour of plastics and elastomers primarily when a mechanical stress is applied and more so at different speed or at different temperatures. With additional insight into more cosmetic attributes such as transparency and barrier properties as these can have a tremendous commercial relevance. | ||||||||
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| Prerequisites : | General physics and general chemistry | ||||||||
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| Workshops : | Rheology and materials laboratory sessions. 1. Run temperature sweep of 1 Hz DMTA trace, resp. 10°C/min DSC trace, on the core-shell impact modifier prepared in CHIM0051; observe rubber and plastic glass transitions. Discuss DSC not matching DMTA. 2. Charpy impact the modified PVC plaque prepared in CHIM0051, repeat with same unmodified PVC; derive and compare the G1cs at room temp. 3. Go to SEM with one broken piece; microtome a specimen edge, stain the slice, and go to TEM. Merge your data with the class and discuss modification efficiency. 4. Estimate yield strength and formulate and cast in proper thickness an aerospace high Tg composite matrix neat resin; measure mode 1 fracture toughness, K1c, at different loading speed; explain the transition. 5. Establish the power law two parameters of non Newtonian fluids for commercial POLYSTYROL at 180°C using weight, length, and time measurements only at the capillary viscometer. 6. Run GPC on same polystyrene and draw conclusions from your data merged with the class. Find the dependence between zero shear viscosity and the MW main averages. | ||||||||
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| Organization : | Lectures 2hr per week during Fall term | ||||||||
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| Written notes : | Course text-notes are partially available. All figures, graphs, and tables are available. Lab text-notes and necessary calibration curves are available. | ||||||||
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| Assessment : | Oral examination following a written preparation of 2 questions at random. | ||||||||
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| Contacts : | jean-marie.liegeois@ulg.ac.be | ||||||||
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ULg : Students and Studies Administration - Academic Affairs
Contact : Monique Marcourt, direction A.E.E.
Date of data : 27/02/2006
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