What is a biodegradable polymer? Give an example of a biodegradable aliphatic polyester.
A polymer that can be decomposed by bacteria is called a biodegradable polymer.
The biodegradable polymer are the polymers which are degraded by the micro-organism within a suitable period so that biodegradable polymers and their degraded products do not cause any serious effects on the environment. They degrade by enzymatic hydrolysis and oxidation. The decomposition reactions involves hydrolysis (either enzymatically induced or by non –enzymatic mechanism) to non- toxic small molecules which can be metabolized or excreted from the body.
The common examples of aliphatic biodegradable polymers are polyglycolic acid(PGA), Polyhydroxy butyrate (PHB), Polyhydroxy butyrates-co-beta hydroxyl valerate( PHBV), Polycaprolactone(pcl), Nylon-2-nylon-6.
These polymers are used mainly for medical goods such as surgical sutures, tissues in growth materials, for controlled drug release, plasma substitutes etc. They are also used in agriculture materials, such as films, seed coatings, fast food wrappers, personal hygiene products etc.
Poly-β-hydroxybutyrate-CO-β-hydroxyvalerate (PHBV) is a biodegradable aliphatic polyester.
Write the names and structures of the monomers of the following polymers:
(i) Buna-S (ii) Buna-N
(iii) Dacron (iv) Neoprene
Arrange the following polymers in increasing order of their intermolecular forces.
(i) Nylon 6, 6, Buna-S, Polythene.
(ii) Nylon 6, Neoprene, Polyvinyl chloride.
Explain the difference between Buna-N and Buna-S.
How are polymers classified on the basis of structure?
Define thermoplastics and thermosetting polymers with two examples of each.
Explain the term copolymerisation and give two examples.
Write the monomers used for getting the following polymers. (i) Polyvinyl chloride (ii) Teflon (iii) Bakelite
How do you explain the functionality of a monomer?
Identify the monomer in the following polymeric structures.
(i)
(ii)
What are the monomeric repeating units of Nylon-6 and Nylon-6, 6?
For the reaction R → P, the concentration of a reactant changes from 0.03 M to 0.02 M in 25 minutes. Calculate the average rate of reaction using units of time both in minutes and seconds.
Write the formulas for the following coordination compounds:
(i) Tetraamminediaquacobalt (III) chloride
(ii) Potassium tetracyanonickelate(II)
(iii) Tris(ethane-1,2-diamine) chromium(III) chloride
(iv) Amminebromidochloridonitrito-N-platinate(II)
(v) Dichloridobis(ethane-1,2-diamine)platinum(IV) nitrate
(vi) Iron(III) hexacyanoferrate(II)
(i) Write structures of different isomeric amines corresponding to the molecular formula, C4H11N
(ii) Write IUPAC names of all the isomers.
(iii) What type of isomerism is exhibited by different pairs of amines?
Why are solids rigid?
Write any two characteristics of Chemisorption.
Write the structures of the following compounds.
(i) α-Methoxypropionaldehyde
(ii) 3-Hydroxybutanal
(iii) 2-Hydroxycyclopentane carbaldehyde
(iv) 4-Oxopentanal
(v) Di-sec-butyl ketone
(vi) 4-Fluoroacetophenone
Which of the ores mentioned in Table 6.1 can be concentrated by magnetic separation method?
Why are pentahalides more covalent than trihalides?
Silver atom has completely filled d orbitals (4d10) in its ground state. How can you say that it is a transition element?
Glucose or sucrose are soluble in water but cyclohexane or benzene (simple six membered ring compounds) are insoluble in water. Explain.
Two elements A and B form compounds having formula AB2 and AB4. When dissolved in 20 g of benzene (C6H6), 1 g of AB2 lowers the freezing point by 2.3 Kwhereas 1.0 g of AB4 lowers it by 1.3 K. The molar depression constant for benzene is 5.1 Kkg mol-1. Calculate atomic masses of A and B.
The time required for 10% completion of a first order reaction at 298 K is equal to that required for its 25% completion at 308 K. If the value of A is 4 x 1010 s-1. Calculate k at 318 K and Ea.
Determine the osmotic pressure of a solution prepared by dissolving 25 mg of K2SO4 in 2 liter of water at 25° C, assuming that it is completely dissociated.
Give plausible explanation for each of the following:
(i) Cyclohexanone forms cyanohydrin in good yield but 2, 2, 6 trimethylcyclohexanone does not.
(ii) There are two -NH2 groups in semicarbazide. However, only one is involved in the formation of semicarbazones.
(iii) During the preparation of esters from a carboxylic acid and an alcohol in the presence of an acid catalyst, the water or the ester should be removed as soon as it is formed.
Which is the last element in the series of the actinoids? Write the electronic configuration of this element. Comment on the possible oxidation state of this element.
Write the chemistry of recharging the lead storage battery, highlighting all the materials that are involved during recharging.
Which meatal in the first series of transition metals exhibits +1 oxidationstate most frequently and why?
How much electricity in terms of Faraday is required to produce
(i) 20.0 g of Ca from molten CaCl2.
(ii) 40.0 g of Al from molten Al2O3.
How will you convert ethanal into the following compounds?
(i) Butane-1, 3-diol (ii) But-2-enal (iii) But-2-enoic acid
Write the mechanism of the reaction of HI with methoxymethane.
this website helped me very much thanks nanba
this website helped me very much thanks nanba
the biodegradable polymer is ? Tell tell me ans.
Thanks Nanba
Gopal