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CHEM 370 - Coggle Diagram
CHEM 370
Basic Definitions
Molecular Weight
Origins
Polymer versus Macromolecule
Polymer Technology
Polysaccharides
Cellulose
Amylose Starch
Chitin
Proteins/polypeptides
Nitrocellulose
Natrural Rubber
Trans-Polyisoprene (Hard Plastic)
Cis-Polyisoprene (Natural Rubber)
Polymer Science
Old idea: Aggregate of small molecules
Chain Like Structure
Properties
Spaghetti Analogy
Bulk State
Solution State
Important Terminology
Monomer
Structural Unit
Repeating Unit
General Structure
Backbone
Pendant Units
Endgroups
Additional Structures
Linear (Common)
Branched
Comb
Ladder
Network
Dendritic
Copolymers
Structural Arrangments
Random
Graft
Alternating
Block
Degree of Polymerization
Monomer Functionality
Types of Reactions
Addition
No small molecule elimination
Opening Double Bonds
Condensation
Small Molecule eliminated
Functional Groups in the backbone
Organic Chemsitry
Polyester
Polyamide
Addition
Molecular Weight Distribution Plot
Ni vs Mi
MALDI_ToF
Average Molecular Weights
Number Average
Weight Average
Viscocsity Average
Mz
Mz+1
Polydispersity Index
Polydisperse
Monodisperse
Differential MWD
Absolute
Normalized
Molecular Weight Measurement Techniques
Assumptions
Applicable to all sample fractions
Magnitude of Instrument response is proportional to polymer, solvent, and temperature
Response is concentration dependent
Each Fraction of the sample contributes independently
Colligative Properties Methods
General Problems
Sensitivity is inversely proportional (1/M)
Biased by low MW impurities
Rare Methods
Ebullioscopy
Cryoscopy
Vapor Pressure Osmometry
Raoults Law
Simplification for a 1 volatile species
Indirect measurement through solvent/polymer solution change in voltage
Error on upper and lower limits
Linear Regression
Membrane Osmometry
Membrane separating solvent and polymer solution
Driven by chemical potential (Solvent to polymer solution) Reach equilibrium
Measurement of change in Coolum height due to displacement caused by osmotic pressure
Osmotic Pressure/Conc versus Conc
Reduce time to reach equilibrium with a dynamic membrane osmometer
End Group Analysis
Titration of End groups
Can work via backtitration
In Organic Solvents
Determines Mn
Light Scattering
Yields Mw
Interaction between light and the compound
Interaction with bonds
n proportional to concentration
Additional Factors
Mw accounts for polydispersity
Only valid for small scattering
Polymer may interact strongly with solvent
Account for solvent background scattering
Constructive and destructive interference
Account for angular or concentration dependence\
Viscosity Measurement
Velocity Gradient
Laminar Flow
Hydrodynamic Radius
Types
Specific
Reduced
Relative
Absolute
Determines Mv
Requires special constant from handbook!
Can be related to Mw
Gel Filtration
Size Seperation
Hydrodynamic Radius/Volume
Separation time is proportional to volume.
Calibration Required
Permiation limits