Synthesis and Physical Properties of Polyester Amides Derived from Lipid-Based Components

Outline Introduction of polyester amide PEA  What is polyester amide  Applications Advantage of Lipid-based components Previous Examples of Lipid-based PEA Objectives and Results Concl

Synthesis and Physical Properties of

Polyester Amides Derived from

Lipid-Based Components

By: Jiaqing Zuo Trent Biomaterials Research Group

March 2011

Outline

Introduction of polyester amide (PEA)

 What is polyester amide

 Applications

Advantage of Lipid-based components

Previous Examples of Lipid-based PEA

Objectives and Results

Conclusions

Ester linkage Amide linkage

Ester linkage: Biodegradability

Amide linkage: Thermal Stability, Mechanical Strength

Biomedical applications:

 Stent-coatings for drug delivery

 Absorbable surgical materials

Material requirements:

 Biodegradable

 Good processing property

 Safely metabolized by human bodies

References:

1 Lee, S.H., et al., Coronary Artery Disease, 2002 13(4): p 237-241.

2 Legashvili, I., et al., Journal of Biomaterials Science-Polymer Edition, 2007 18(6): p 673-685.

3 Guo, K and C.C Chu, Journal of Polymer Science Part a-Polymer Chemistry, 2005 43(17): p 3932-3944.

 Potentially have good performance

as petroleum based materials

References:

1 Hojabri, L., X.H Kong, and S.S Narine, Biomacromolecules, 2009 10(4): p 884-891.

2 Williams, C.K and M.A Hillmyer, Polymer Reviews, 2008 48(1): p 1-10.

Previous Examples of

Lipid-based PEA PEA derived from:

Pongamia glabra oil Linseed oil

Disadvantages:

 Not all building blocks are from sustainable materials

 Not suitable for biomedical applications

References:

1 Ahmad, S., S.M Ashraf, and F Zafar, Journal of Applied Polymer Science, 2007 104(2): p 1143-1148.

2 Zafar, F., et al., Journal of Applied Polymer Science, 2005 97(5): p 1818-1824

3 Ahmad, S., et al., Progress in Organic Coatings, 2003 47(2): p 95-102

O

O

O

O R R O

R O

HN OH

OH

OH

OH R

O

OH

O HO O NaOCH3

Diethanolamine

Objectives

1 Synthesis of PEAs with different ester/amide ratios

PEA (I) with ester: amide= 1:1

PEA (II) with ester: amide= 2:1

PEA (III) with ester: amide= 3:1

Hypotheses:

1 The increase of ester to amide ratios in the PEA

structure will result in a decrease of thermal stability

2 The increase of ester to amide ratio in PEA structure

will decrease the glass transition temperature

3 The increase of ester to amide ratio in PEA will result in

increased elasticity

4 The increase of ester to amide ratio in PEA structure

will diminish the mechanical strength of the polymer

Step 2: Polyester amide preparation

PEA

ester I ester II ester III

amide I amide II amide III

Mn Mw PDI

 GPC results

Mn: Number average molecular weight

Mw: Weight average molecular weight PDI: Polydispersity index

the repeating unit (g/mol)

484 712 1025

Hydrogen bonding sites 86 58 44Length of the repeating

unit (Å) 31 48 73Hydrogen bond density

(1/Å) 0.065 0.042 0.028

WL3 (%)

T D4 ( o C) WL4

(%)

T D5 ( o C) WL5

(%) PEA (I) 367 35.4 411 33.7 446 13.3 461 6.2

PEA (II) 371 35.6 402 29.8 432 25.6 444 4.3 458 3.7

PEA (III) 383 31.0 410 30.1 452 28.2 467 3.5

T D:Decomposition Temperature WL: Weight Loss

• Viscoelastic properties

• Measuring glass transition temperature

3) Dynamic Mechanical Analysis (DMA)

22

24

Biodegradability increases

29

2θ (º) d-spacing (Å)

α-form (helical conformation)

β-form (planar conformation)

Sources and Structures T D ( o C) T g ( o C) T m ( o C) Tensile

strength Elongation Features

Gallic acid, amino acid

249-305 (5%) 141-168 180 Highly branched, aromatic

Castor/soyabean oil, DEA, adipic acid and Zn(OH) 2

activities

 Comparison of lipid-based polyester amides

Di-nitrophenyl sebacate and

p-toluenesulfonic acid salt of phenylalanine butane-1,4-diester

L-30 109.2

1,6-hexanediamine, sebacic acid octadecanedioic acid, and ε-caprohctone

231 to 391 -24 to 48 64 to 218

Different aromatic diols, diacids and 4-acetamidophenol (AP) 80, 87 3.18GPa, 3.94GPa < 4Glucitol(diol), amino acid, aliphatic

dicarboxylic acid 40 to70 124,164Copolymer 280 to 366 80 to82 240 to 250α-amino acids, diols and fatty

dicarboxylic acids

6.7 to 32.8 0.02 to 12.08 65 to 882

BAK 2195Nylon 6,6; Diethylene glycolButanediol, Adipic acid

 Comparison with petroleum-based polyester amides

 Three PEAs with different ratios of ester and amide

linkages were synthesized from lipid-based components

 The PEAs were fully characterized

 Functionality of the PEAs were investigated from a

structural perspective

 PEA’s had superior properties to all other lipid-based PEAs

 PEA’s had comparable and sometimes superior

properties to petroleum-based PEAs

Hypothesis #2: The increase of ester to amide ratio in PEA structure

decreased dramatically the glass transition temperature

a The increase of ester to amide ratio in PEA structure decreased

dramatically the glass transition temperature

wider range

Hypothesis #4: Mechanical strength of the polymer was diminished when ester to amide ratio in PEA structure was increased

The tensile strength and the Young’s Modulus are both decreased

when ester to amide ratio increased

Future Work

 Investigate the biodegradability of PEAs with varying ratios

of ester to amide groups

 Increase the molecular weights of the synthesized PEAs to further improve the thermal and mechanical properties

(such as changing the amino acid to polypeptide or

increasing the reaction temperature)

 Study the effects of crystallinity on the physical properties

of the PEAs

 Prepare a PEA with an ester to amide ratio of 4:1 in order

to model the trend observed in the physical properties

versus ester to amide ratio

Thank You !