lab 11 report

From the practical standpoint, is it better to use a "good" solvent or a "poor" solvent when measuring polymer molecular weight? Explain.

Discuss the suitable initiator to start an addition polymerization. Define what is auto-acceleration, what causes this effect and how to minimize this effect. Briefly discuss emulsion and suspension polymerization techniques.

How is a sample of a polymer taken for characterization & analysis?

Determine the effect of Column A to Column B (increase, decrease, or no effect).

Discuss the reasons for the differences in glass transition temperature for the following pairs of polymers. Hint: check factors that affect Tg Polyethylene (-120°C) and polypropylene (-20°C)

Investigate and explain two experimental methods to measure the molecular ` weight distribution of polymers.

5. Explain the determination of molecular weight of polymer samples usingdilute viscosity measurement.

Release HCI has a strong catalytic influence on the dehydrochlorination of PVC according to: * -Chain transfer mechanism -lonic-molecular mechanism -Free radical mechanism Some additives able to maintain polymer properties through: * - Enhance the value of polymers by improving their properties. - Help to prolong the service life of polymer applications. - Protect the polymer chain and unchanged molecular weight. Model of crystalline polymers structure prevents flow easily due to close space between: * - Molecular chains O - Tm and Tg O - Processing range and degradation

1. Component Container Stretch Wrap Pallet Product Material Polypropylene Polystyrene Wood Ca(OCI)2 Weight (kg/pallet) 48 0.5 15-18 725 Based on the above table, answer the following questions. (a) Discuss the possibility of fire at the calcium hypochlorite Ca(OCI)2 storage warehouse. Include your assumption on how the fire could spread in the storage warehouse. (b) Recommend solutions to avoid fire occur at the storage warehouse. (10) (10) (Total / Jumlah: 20 )

Calculate the number average molecular weight corresponding to the molecular weight distribution for the synthetic polymer sample fractionated in the graph below if the polydispersity index is 1.25

What are impurity defects?

Electrostatic charges can also be produced on the surfaces of polymeric materials due to: -Lowering the surface resistance of polymeric materials -Low surface conductivity of most polymeric materials -Repeated deformations and friction occurs on the polymeric materials Conduction channels formed on the surface of plastics due to: * -Hygroscopic nature of antistatic agent -Impurities adsorbed from the air moisture -lonizes antistatic agent in the presence of water ESO shows poor migration stability when used in a large amount with PVC due to: * -Ability to bind hydrogen chloride -Convert unreacted double bonds epoxide groups -Incompatibility with PVC matrix

9 This polymer is composed of 2 monomer units: an acid chloride and an amine. In the box below, draw the structure of both monomers. 1040 C-N n t • You do not have to consider stereochemistry. • You do not have to explicitly draw H atoms. • Do not include lone pairs in your answer. They will not be considered in the grading. • Draw one structure per sketcher. Add additional sketchers using the drop-down menu in the bottom right corner. • Separate structures with + signs from the drop-down menu. 99-87 + T ? [F

Sketch and label the expected stress-strain curves at room temperature for lightly cross-linked poly(butadiene) and reinforced poly(methyl methacrylate). Compare the behaviour of each specimen in terms of modulus and toughness.

With respect to the monomers and the subsequent molecular structures, select all correct descriptions from below for the mixing, pre-pregging and curing of a thermoset polymer resin during a composite manufacturing process. Unreacted monomers are soluble during mixing. O During pre-pregging/curing small branched molecules are partially soluble. Unreacted monomers are insoluble during mixing. In the cured composite crossed-linked polymer chains are insoluble. In the cured composite crossed-linked polymer chains are partially soluble. O O O O O

A characteristic of the stoichiometry of condensation (step-growth) polymerization reactions is that small molecules, like H2O, HCl or others, are released as reaction by-products. In a commercial polymerization reactor, what might be some process implications of the release of small molecules like H2O or HCl?

I need the answer quickly

Plot the tensile strength of the polymers in table 16-2 as a function of the number of aromatic (benzene) rings in the monomer.

8)

Based on the answer to my question my follow-up question refers to processing. How does hydrogen bonding interactions affect the processing temperatures of these polymers? And what would we expect to occur? Why does hydrogen bonding affect thermal stabiltiy (thermo-oxidative stability) and affect degradation of the macromolecule. What is the mechanism of this interaction?

Why thermal analysis is important for polymers but not for organic molecules?

Determine phosphate concentration of a water sample using the following information: Standard curve- slope: 1763.2 y-int: 0.011806 R^2: 0.99181 Absorbance of water sample: 0.013

What would be the effect of Column A to Column B? Determine if Column B will increase, decrease, or no effect.