Mr.Praveen Mr.Srinivas For their support and encouragement Thank You

1. Development of Hyperbranched Polymers
for Coatings & Allied Field Applications
K.Sasidhar
UGC-SRF, ID.No-7742
Research Supervisor: Dr.K.V.S.N.Raju
Polymers & Functional Materials Division
CSIR-IICT, Hyderabad.

2. Scheme of Presentation
 Coatings
 Dendritic Polymers
 Dendrimers Vs Hyperbranched Polymers
 Advantages of HBPs
 HBPs for Eco-friendly High Solids Coatings
 Synthesis of HBPs
 Degree of branching in HBPs
 Applications of Hyperbranched Polymers
 Research at CSIR-IICT
 Linkage to my research work
 Summary

3. Coatings
Coating is defined as materials which on application to substrates
form a uniform coherent film with good adhesion and functional properties.
(paint -color, generally paint is used for decorative purposes)
Functions
Levelling, Antisettling, Flow, Optical, Defoamer etc.-Surfactants
 Decoration
 Protection
Additives
 Medical
..
The Constituents
Alkyd
Polyester
Polyurethane
Acrylics
Phenolics
Polyamide
;;
renewable
Polymer/Binder
SOLVENT
TiO2
Clay
Cal. carbonate
Talc
Iron oxide
Zinc oxide etc.
Phthalocyanine
Al-flakes ……
 Self Cleaning
 Self Healing
 Scratch Resists
 Anti Reflective
 Heat Resists
 Self Stratifying
 Antimicrobial
 Conductive
Filler/Pigment
 Solar Paint

4. Dendritic polymers
Dendritic polymers are macromolecular architecture. They represent highly
branched globular macromolecules,
They are subdivided according to their degree of structural control into
three different categories,
(a) random hyperbranched polymers
(b) dendrigraft polymers
(c) dendrimers
Polymers 2012, 4, 355-395

5. Dendrimers Vs Hyperbranched polymers (HBPs)
Dendrimers
Hyperbranched polymers
Dendrimers are highly uniform, 3-dimensional,
monodisperse polymers with a tree-like, globular
structure and a large number of functional groups
With perfect molecular architecture.
Hyperbranched polymers represent another class of
globular, highly branched macromolecules with a
large number of functional groups. However, unlike
dendrimers, hyperbranched polymers exhibit
irregularity in terms of branching and structure.
Dendrimers are monodisperse [Degree of
branching (DB) =1]
HBPs are polydisperse [DB<1]
Highly symmetrical in nature
Unsymmetrical in nature
Dendrimer synthesis requires absolute control over
all the synthetic steps.
HBPs can be prepared by a one pot
polycondensation process
The synthesis of dendrimer is quite tedious job and
requires several protection and deprotection steps.
Easily synthesized by a one pot method
Final yield is very low so can not be applicable
industrially
Final yield is high so can be synthesized in large
scale

6. Applications of Hyperbranched Polymers
 Coatings
 Electrolytes for DSSC
 Energy Harvesting
 Drug Delivery
 Super hydrophobic
 Renewable

7. Advantage Hyperbranched Polymers for Coatings
Advantages of HBPs:1. Possess many similar properties of dendrimers
2. Can be produced in large scale at a reasonable cost
3. Have a multitude of end-groups
4. The highly branched architecture leads to globular and voidcontaining shapes, high solubility, low solution or melting viscosity
compared to linear analogues

8. Commercially developed HBPs

9. HBPs for Eco-friendly High Solids Coatings
• Generally in case of linear polymers viscosity of a polymer solution increases linearly
with increase in molecular weight but in case of hyperbranched and dendritic polymers this
increment is not linear they show low viscosities at high molecular weights which is mainly
due to less number of molecular engagements in HBPs
• Low Viscosity at higher molecular weight which in turn results in higher solids with excellent
Mechanical properties is key for low VOC eco-friendly coatings
• The peripheral reactive functional groups helps in crosslinking and adding functional
properties (e.g. dual cure systems)
Prog. Polym. Sci. 32 (2007) 352–418

10. Synthesis of HBPs
Divergent Approach
Divergent approach: Core to periphery
Convergent approach: Periphery to core
Divergent approach is easier than Convergent approach
Convergent Approach

11. Degree of branching in HBPs
Fr echet and coworkers gave an equation for the DB at first, as shown in Eq.
There are three types of units present in HBPs
Linear (L), Terminal (T) and Dendritic (D) units
•The degree of branching of a
perfect Dendrimer equals 1,
linear polymer has a DB of 0
• For HBPs DB is less than 1
• The fractions of D-, L- and Trepeating units are usually
determined by NMR spectroscopy
Prog. Polym. Sci. 29 (2004) 183–275

12. Example for Degree of Branching Calculation
Linear Unit
Terminal Unit
O
O
HO
O
O
HO
O
Dendrintic Unit
C
HO
O
O
Dendrintic Unit
O
C
C
Linear Unit
0.5
0.4
Degree of branching=(D+T)/(D+L+T)= (0.1+0.5)/(0.1+0.4+0.5)=0.6
This Hyperbranched polyester has 60 %degree of branching
0.1
O
Terminal Unit

13. Applications of Hyperbranched Polymers

14. Fast Cure Coatings
The large number of reactive groups will, upon reaction, rapidly form a
network to give a fast cure.
It is believed that the rapid cure also contributes to the reactive groups being
predominantly at the surface which, in combination with the dense structure,
which makes them less possible to entanglement and hence more readily
accessible for reaction.
Surface Coatings International Part B: Coatings Transactions 333 Vo189, B4,269 380, December 2006

15. Hyperbranched Epoxies as Tougheners for
Enhanced Mechanical Properties
• Large amounts of epoxy resins are used world-wide in coatings,
adhesives, moulding compounds and polymer composites
• Dendritic hyperbranched polymers (HBPs) show outstanding
performance as tougheners in epoxy resins
• When using 10% of the HBP toughener, the largest toughening effect
is observed with a 10-fold increase in GIc (toughness)
• With core–shell particles, it is necessary to use up to 30% of
modifiers in order to obtain a comparable toughening effect to 5% of
HBPs
• The critical strain energy release rate, GIc, of a DGEBF resin is
increased by a factor of 6 from 120 J/m2 to 720 J/m2 using only a 5%
modifier weight content
Dendritic hyperbranched polymers as tougheners for
epoxy resins Polymer, Volume 40, Issue 9, April
1999, Pages 2249-2261
Louis Boogh, Bo Pettersson, Jan-Anders E. Månson

16. HBPs in Nanocapsules
Molecular nanocapsules and their corresponding host/guest compounds offer an
attractive potential for use in a wide variety of applications ranging from
controlled drug release, phase-transfer agents, dispersion of polar dyes in
hydrophobic polymers, preparation of inorganic/organic hybrid nano particles.
C15H31COCl
Palmitoyl acid chloride
Amphiphilic molecular
nano capsule
Angew. Chem. Int. Ed. 1999, 38, No. 23
Congo Red

17. Hyperbranched polymers developed
by our research group

18. Summary & Conclusions
1. Hyperbranched polymers show better thermal and mechanical
properties than linear polymers.
2. Hyperbranched polymer based coatings are with low VOC, high solid
content Eco-friendly because they show lower viscosities at high
molecular weights.
3. Due to large number of end functionalities, HBP based coatings
curing is very fast.
4. HBPs crosslinked epoxies are showing excellent toughness than
linear one’s.
5. These are better alternatives to dendrimers for many applications.

19. Acknowledgements
University Grants Commission (UGC) for Financial support
Director-IICT for granting permission to carry research work
Dr. K.V.S.N. Raju- Research Supervisor
(Head PFM Division)
Dr.Ramanuj Narayan
Mr.Amit Kumar
Mr.Yugandhar Raju
Colleagues:
Dr.Aswini Kumar Mishra
Dr.Kishore Kumar Jena
Mr.Siyanbola Tolu
Mr.Shaik Allauddin
Mr.Nagaraj Goud
Mr. Ram Keval Yadav
Mr.Rajnish Kumar
Mr.Rupchand prajapath
Mr.Varaprasad
Mr.Rajnish pandey