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Reading (Odian Book): Chapter 1. Polymer Parameters. Chemical structure Chemical composition and distribution Sequence length and distribution Molecular weight and distribution Chain isomerism Morphology Topology Additives Cost. Chemical Composition. Chemical Composition.
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Reading (Odian Book): Chapter 1
Polymer Parameters • Chemical structure • Chemical composition and distribution • Sequence length and distribution • Molecular weight and distribution • Chain isomerism • Morphology • Topology • Additives • Cost
Chemical Composition • Infinite chain model notation • How best to characterize? • Why does sequencing matter? • Synthetic approaches? • Compositional distribution? • Branching? (refer to as topology…)
Polymer Parameters • Chemical structure • Chemical composition and distribution • Sequence length and distribution • Molecular weight and distribution • Chain isomerism • Morphology • Topology • Additives • Cost
Molecular Weight Property “X” Molecular Weight “X” = tensile strength density Tg etc
Molecular Weight Σni Mi Σwi Mi Mn = Mw = Σni Σwi
Molecular Weight Σni Mi Σwi Mi Mn = Mw = Σni Σwi • Populations • Memphis, TN 700,000 • Montrose, CO 10,000 • Effingham, IL 12,000 • Freeman, SD 1,500 • What is the Average Population? • 723,500 ÷ 4 = 180,875 • Of these four cities, the average citypopulation is 180,875 • Let’s think about the people… • What size city does the average person among these populations live in? • The average person does not live in a town of a population of 180,875… • Most of the people live in a town with a lot more than 180,000 people… • Need a weighted average
Molecular Weight Σni Mi Σwi Mi Mn = Mw = Σni Σwi • Populations • Memphis, TN 700,000 • Montrose, CO 10,000 • Effingham, IL 12,000 • Freeman, SD 1,500 • Weighted average • 700,000 ÷ 723,500 = 0.9675 • Take fraction and multiply that by the population of Memphis 0.9675 x 700,000 = 677,263 • Do the same for the others • 700,000 x 700,000 / 723,500 = 677,263 • 10,000 x 10,000 / 723,500 = 138 • 12,000 x 12,000 / 723,500 = 199 • 1,500 x 1,500 / 723,500 = 3 677,603 • The average person lives in a city of about 677,600 • More realistic than saying the average person lives in a city of 180,000!
Molecular Weight Σni Mi Σwi Mi Mn = Mw = Σni Σwi • What is the significance of the spread? • Polydispersity index (PDI) • PDI of polypeptides and DNA • How does magnitude of MW relate to synthesis? • How do you control PDI?
Gel Permeation Chromatography • What is principle behind GPC? • Direct or indirect method? • Why so useful? • Drawback? Detector Response Elution Volume (mL)
Polymer Parameters • Chemical structure • Chemical composition and distribution • Sequence length and distribution • Molecular weight and distribution • Chain isomerism • Topology • Morphology • Additives • Cost
Chemical Composition Distribution (CCD) • Interplay between CCD and MWD… • How to measure? • Ramifications? • Catalysis? • Phase separation? • Optical properties? • Degradation rates? • Toxicity? • Sequence length distribution
Polymer Parameters • Chemical structure • Chemical composition and distribution • Sequence length and distribution • Molecular weight and distribution • Chain isomerism • Morphology • Topology • Additives • Cost
Chain Isomerism • Regio-isomers • Stereo-isomers • Geometric isomers • Conformational isomers
Regio-isomers defect