--%>
Assignment Help - homework help

What are biodegradable polymers? Present some examples.

 

These are polymers that can be broken into small segments by enzyme-catalysed reactions. The required enzymes are produced by microorganism. It is a known fact that the carbon-carbon bonds of chain growth polymers are inert to enzyme-catalysed reactions, and hence they are non biodegradable. To make such polymers biodegradable we have to insert certain bonds in the chains so that these can be easily broken by the enzymes. Now when such polymers are buried as waste, microorganisms present in the ground can degrade the polymer.

One of the most excellent methods of making a polymer biodegradable is by introducing hydrolysable ester group into the polymer.

For example if acetal is added to an alkene undergoing radical polymerisation, ester group will be inserted into the polymer.

The weak links in the polymer are susceptible to enzyme catalysed hydrolysis.

Aliphatic polyesters are one of the significant categories of biodegradable polymers. Some other examples of biodegradable polymers are described below:

(i) PHBV (Poly-hydroxybutrate-co- 856_Biodegradable1.png-hydroxy valerate):  it is a copolymer of 3-hydroxy butyric acid and 3-hydroxypentanoic acid.
378_Biodegradable.png 


PHBV is used in orthopaedic devices and controlled drug release. The drug put in PHBV capsule is released after this polymer is degraded by enzymatic action. It can also be degraded by bacterial action.

(ii) Poly glycolic acid and poly lactic acid: these are also biodegradable polymers and are used for post operative stitches. These are bioabsorbable structures.

(iii) Nylon-2-Nylon: it is an alternating polyamide copolymer of glycine2233_Biodegradable3.png  and amino caproic acid1005_Biodegradable4.png and is biodegradable.

907_Biodegradable2.png

 

 

 

 

 

   Related Questions in Chemistry

  • Q : Question on molality Provide solution

    Provide solution of this question. Which of the following concentration factor is affected by change in temperature : (a)Molarity (b) Molality (c)Mole fraction (d)Weight fraction

    		•
  • Q : Molarity of the final mixture Can

    Can someone please help me in getting through this problem. Two solutions of a substance (that is, non electrolyte) are mixed in the given manner 480 ml of 1.5M first solution + 520 ml of 1.2M second solution. Determine the molarity of the final mixture

    		•
  • Q : Why aryl halides are less reactive?

    Aryl halides are much less reactive towards nucleophilic substitution reactions than haloalkanes. The less reactivity of aryl halides can be described

    		•
  • Q : P- block why pentahalids are more

    why pentahalids are more covalent than tetrahalids

    		•
  • Q : Molecular weight of solute Select right

    Select right answer of the question. A dry air is passed through the solution, containing the 10 gm of solute and 90 gm of water and then it pass through pure water. There is the depression in weight of solution wt by 2.5 gm and in weight of pure solvent by 0.05 gm. C

    		•
  • Q : Importance of organic chemistry

    Describe the importance of organic chemistry?

    		•
  • Q : Quantum Mechanical Operators The

    The quantum mechanical methods, illustrated previously by the Schrödinger equation, are extended by the use of operators. Or, w

    		•
  • Q : Preparation of normal solution Give me

    Give me answer of this question. What weight of ferrous ammonium sulphate is requiored to prepare 100 ml of 0.1 normal solution (mol. wt. 392): (a) 39.2 gm (b) 3.92 gm (c)1.96 gm (d)19.6 gm

    		•
  • Q : Number of electrons in the benzene

    Describe the number of electrons in the benzene? Write a short note on it?

    		•
  • Q : Neutralization of sodium hydroxide How

    How much of NaOH is needed to neutralise 1500 cm3 of 0.1N HCl (given = At. wt. of Na =23): (i) 4 g  (ii) 6 g (iii) 40 g  (iv) 60 g

    		•