The direct polycondensation has 3 main steps:
1. Removal of water.
2. Polycondensation of oligomer.
3. Melt condensation that makes PLA with high molecular weight.
Direct polycondensation of lactic acid is the modest reaction that forms lactide simultaneously by the decomposition processes and it is not used for the large production of PLA [19-22]. Back in the days, the direct polycondensation was assumed as the reaction that produces inadequate polymers with low…
Where M.R is the moisture loss ratio, M_0 is the initial moisture content, M_t is the moisture content at time t, M_e is the equilibrium moisture content, t is time (minutes), and a, b, c, and k are constants.
For the effectiveness of diffusivity, Fick’s equation was used (5) to estimate the dehydration kinetic of different osmotic conditions.
M.R=((M_t-M_e)/(M_0-M_e ))=〖8/π^2 e〗^((-(π^2 Dt)/(4L^2 )) ) …(5)
Where D is the effective diffusivity, and L is the length of the (cubical) sample.…
In this assignment we are going to elaborate on the role of aqueous humor and vitreous humor in maintaining the pressure of the globe, the structures related to the humor, functions of the humors, origin and also pathology related to them.
PHYSIOLOGY OF THE AQUEOUS HUMOR
The aqueous humour is a transparent fluid similar to plasma, but containing low protein concentrations. It is secreted from the ciliary epithelium (a structure supporting the lens). It is located in the…
can react with the cation present in the
In step 5, water was added to the solution and then the test tube was heated so that the bonds
holding the compounds in the precipitate together could effectively break. PbCl₂ has a higher
water solubility, so if a yellow precipitate formed, then that would have confirmed that lead was
present. If not, then extra steps were needed to be taken to confirm the presence of silver.
In step 12, K₂CrO₄ was added because if barium was present, it would…
I predicted that liquid A was glycerine due to a calculated density of 1.38 g/mL. However I was wrong the actual density of liquid A was 1.38 g/mL and the substance was actually corn syrup. Therefore the percent of error for the density of liquid is 1%. For liquid B I had predicted that its substance would be Glycerine due to the calculated density of 1.19 g/mL. I was incorrect for the density of liquid B which was actually 1.26 g/mL, but because the calculated and actual densities…
A important tests were performed on the product to pressure the results: melting point value, percent yield, IR, and TLC. The experimental melting point value was found to be a range of 165-167 ºC being a little lower than the literature value for camphor, the intended product, was 175 ºC. The sharp range was resulted in a slightly pure product. The percent yield was lower than expected which can be the reason most of the product was lost during the extraction and almost completely sublimated…
Describe the Properties of Biopol
Biopol is a copolymer made of the monomers PHV and PHB. PHB alone, with its short methyl side chain, is brittle and has very high crystallinity, meaning it cracks easily. Due to its high crystallinity and overall unsuitable properties for industrial use, PHV has been added to created PHBV, or Biopol. Biopol is semicrystalline, meaning it can still crystallize as well as melting at a lower temperature than PHB, making it industrially suitable. Due to its long…
Investigating if dissimilar sized candles have the capability of drinking equivalent quantity of water.
Aim: The drinking candle science experiment is quite enthralling, as when performed, you'll observe a burning candle drinking up all the water kept beneath it due to the behaviour of the atmospheric pressure. The aim of this experiment is to investigate if unlike sized candles have the capability of drinking the same amount of water.
Hypothesis: With all the information given on different…
Which one of the fo llowing is often easily separated into its components by simple techniques such l)
as filtering or decanting?
A) homogeneous mixture
0 heterogeneous mixture
2) An clement cannot 2)
A) be part of a heterogeneous mixture
Ji,) be a pure substance
is corrccl for ___ _ 19)
A) elements B) homogeneous mixtures
Ohcterogeneous mixtures D) compounds
20) Which of the fo llowing is an example of a lieterogeneous mixture?
@ oil and vinegar B) 70%…
charged ions are separated, by altering the pH of the solution; which shifts the equilibrium of the molecules. During this lab we will separate two compounds from one solute that will be formed by amalgamating a ‘slurry’ – provided by the instructor. Resin or cellulose is used to create a sound support unit in order maintain a constant positive or negative charge respectively, this will allow separation to occur when equilibrium is shifted during the reaction. The column will have a support unit…