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.
The decomposition of NH3on platinum surface is zero order reaction. What are the rates of production of N2and H2if k = 2.5 x 10-4mol-1L s-1?
How many geometrical isomers are possible in the following coordination entities?
(i) [Cr(C2O4)3]3-
(ii) [Co(NH3)3Cl3]
Why are vitamin A and vitamin C essential to us? Give their important sources.
Name a sweetening agent used in the preparation of sweets for a diabetic patient.
The half-life for radioactive decay of 14C is 5730 years. An archaeological artifact containing wood had only 80% of the 14C found in a living tree. Estimate the age of the sample.
What are the expected products of hydrolysis of lactose?
The oxidation number of cobalt in K[Co(CO)4] is
(i) +1
(ii) +3
(iii) -1
(iv) -3
Predict the number of unpaired electrons in the square planar [Pt(CN)4]2- ion.
Explain why
(i) the dipole moment of chlorobenzene is lower than that of cyclohexyl chloride?
(ii) alkyl halides, though polar, are immiscible with water?
(iii) Grignard reagents should be prepared under anhydrous conditions?
In the series Sc (Z = 21) to Zn (Z = 30), the enthalpy of atomization of zinc is the lowest, i.e., 126 kJ mol−1. Why?
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