A spherical rubber balloon has an initial thickness of 0.45mm, and diameter 250mm. Final diameter of 1000mm. Find final thickness, true stress in the plane of the balloon wall, Air pressure required. (Assume rubber is idea and obeys Guassian statistics, and take the shear modulus to be 1MPa.)
How does Gaussian theory for elasticity compare to actual experiments (in compression and tension), and why?
Homopolymer A has a Tg of 80C, homopolymer B has Tg of 70C. Estimate Tg of a 30/70 random copolymer of A and B. What assumptions should be made and compare all relationships that can be used and discuss which is more accurate.
I am trying to figure out how, for the entropy of mixing of two polymers, one gets from: Change in entropy of mixing (delta S sub m) = k[(N1 + N2) ln (N1 + N2) - N1 ln N1 - N2 ln N2] to the result: change in entropy of mixing (delta S sub m) = -k(N1 ln v1 + N2 ln v2) where v1 and v2 are the volume fractions of the two ...continues
A brittle sample of polystyrene behaves elastically in tension, until it breaks in two when extended 2.2%, under a load of 55MPa. What is the toughness of this sample? i know i may use the stress strain curve to solve this problem? (Force vs elongation)... but how do i solve the toughness of the sample?
Look over a creep compliance problem I did involving time temp superposition
I have attached my solution to a creep compliance problem. I need someone to go over it and point out any mistakes I made. Thanks! The problem involves a creep compliance function of a polymer at 35 C: D(t) = 2 - e ^ (-t/1000) GPa ^ -1 where t is in hours. The polymer is made into a tensil specimen and heated to 70 C ...continues
given Kc and moles of produced in reaction calculate concentration at equilibrium
The equilibrium constant Kc for the reaction is 54.3 at 430 deg C H2(g)+I2(g) f/r 2HI(g) At the start of the reaction there are 0.714 mole of H2, 0.984 mole of I2, and 0.886 mole of HI in a 1.90 L reaction chamber. Calc. concentrations of the gases at equilibrium [H2]= [I2]= [HI]=
Discuss second order non-linear optical (NLO) behaviour in polymers?
Polymer PE by free radical polymerization: Why not a high-performance material
Explain using chemical structures why polyethylene synthesized by free radical polymerization is not a high-performance material (e.g. mostly used for supermarket bags and similar cheap commodities ).
Notes on synthesis on dendritic macromolecules (dendrimers)?
