MASS SPECTROMETRY FOR

FORENSIC ENGINEERING OF ADVANCED POLYMER MATERIALS

School of Biology, Chemistry and Forensic Science

Faculty of Science and EngineeringUniversity of Wolverhampton

Polish Academy of SciencesCentre of Polymer and Carbon Materials

Marek M. Kowalczuk

Introduction - Forensic engineering Forensic engineering of advanced polymeric

materials Case studies:

• non-woven fabrics made from PLGA with low toxicity

• bioactive conjugates from natural and synthetic PHA

• biodegradable packaging materials for long shelf-life applications

Conclusion

OUTLINE

Forensics

Forensic Anthropology

ForensicChemistry

Forensic Entomology

Forensic Maths

Forensic Nursing

ForensicOdontology

Forensic Reconstruction

ForensicTechnology

ForensicToxicolog

yLatent

Print IDDocument Examiner

Forensic Computer Specialist

Forensics | Fields

Forensic Engineering

“Forensic engineering is considered to be the investigation of materials, products, structures or components that fail or do not function as intended, the results being used for legal proceedings”

However, the role has expanded and today forensic engineers are also called upon to add their expertise in a much wider context

Today forensic materials engineers apply their skills on a much wider stage

Design

Production

AssetIntegrity

IncidentInvestigation

FailureInvestigation

PropertyEvaluation

ConditionAssessment

Expert Withess

The classical forensic polymer engineering concerns a study of failure in polymer products

The classical forensic polymer engineering

This area of science comprises fracture of plastic products, or any other reason why such a product fails in service, or fails to meet its specification

Step-growth polymers can suffer hydrolysis in the presence of water. Reaction is catalysed by acid or alkali

Failed fuel pipe at right from road traffic accident

Close-up of broken fuel pipe

The nylon connector had fractured by stress corrosion cracking due to a small leak of battery acid

Hydrolysis

Conclusions: • This study revealed that low molecule weight PLLA and PCL microparticles

increased cytotoxicity and dysregulated endothelial cell function, which in turn enhanced elastase release and polymer degradation• These indicate that polymer or polymer-coated stents impose a risk of

endothelial dysfunction after deployment which can potentially lead to delayed endothelialization, neointimal hyperplasia and late thrombosis

Forensic engineering of advanced polymer materials deals with the evaluation and understanding of the relationships between their structure, properties and behavior before, during and after practical applications

Chemical and Biochemical Engineering Quarterly, doi: 10.15255/CABEQ.2014Polymer Degradation and Stability, 110 (2014) 518–528

Forensic engineering of advanced polymer materials

structure

BIOCOP ®

properties

Zr(Acac)4

Macromolecules, 2001, 34, 5090-5099Journal of Polymer Science Part A, 42 (2004) 1886-1900

Case study 1: Non-woven fabrics made from PLGA with low toxicity

O

O

O

O

O

O

O

O

CH3

CH3

O

CH3 CH3

n + m ‒(O-CH2-C-O- CH2 -C)n–(O-CH-C-O-CH-C)m‒

OOO

Project “Biodegradable Fibrous Products” involved developing technologies for manufacturing textiles from biodegradable aliphatic (co)polyesters

Properties and parameters of the PLGA non-woven fabrics thermal bonding process

Polymer Degradation and Stability, 110 (2014) 518-528

Incubation in water at 37°C

The effect of the solvent-free non-woven fabrics formation method on the release rate of lactic and glycolic acids from the tin-free poly(lactide-co-glycolide) nonwovens

Sample name

Processtemp. [°C]

Pressingtime [s]

Surface mass [g m-2]

Thickness [mm]

Apparent density [kg m-3]

NWM 1 RT 0 560.44 2.85 196.6456NWM 2 60 120 888.57 1.48 600.3851NWM 3 60 60 832.44 1.78 467.6629NWM 4 60 60a 894.22 1.70 526.0118NWM 5 RT 0b 532.44 1.63 326.6503

a with additional stress of 100 Ba; b cold rolled at 12 Ba

Trends in Biomaterials and Artificial Organs, 25 (2011) 79-85

Schematic representation of hydrolytic degradation of polymer

Stage- IWater diffusion

Stage- IIPolymer Hydrolysis

AutocatalysisLittle mass loss

Stage- IIIOligomers diffusion

Drug releaseMass loss

Stage- IVPorous structure

Homogeneous degradation

Water moleculeAcidic oligomersDrug moleculeVoids due to oligomers diffusion

pH changes during the incubation of NWM samples in water at 37°C

HPLC traces of lactic acid (LA)and glycolic acid (GA) in the medium

after 180 days of degradation

Sample name

Time [days]

Content GG units [mol%]

Weight loss [mg]

Weight loss [%] Mn

Mn loss [%]

D

NWM 10 17 0 0 22 300 0 3.0

90 16 9.33 5.9 6 800 70 4.7180 13 21.47 16.4 2 400 89 4.7

NWM 20 17 0 0 22 600 0 3.0

90 15 12.66 5.7 7 500 67 3.8180 13 90.3 21.8 2 200 90 3.1

NWM 30 17 0 0 22 200 0 3.1

90 16 16.01 6.6 7 000 68 3.8180 13 69.05 20.1 2 400 89 3.3

NWM 40 17 0 0 22 000 0 3.0

90 16 12.68 6.4 6 700 70 4.3180 14 48.43 17.7 2 500 89 3.6

NWM 50 17 0 0 22 300 0 3.0

90 16 7.05 6.7 8 000 66 4.6180 14 24.08 13.5 3 100 86 4.4

Poly(lactide-co-glycolide) nonwovens

Schematic representation of surface erosion and bulk erosion

ESI-MS/MS spectrum of the ion of [HO-L11G3]- at m/z 983 terminated by hydroxyl and carboxyl end groups and containing three GA co-monomer units

a) ESI mass spectrum (negative ions) of the PLGA non-woven fabrics (sample NWM 2) remaining after 180 days of incubation under abiotic conditions; b) Spectral expansion in the range m/z 895-1035

Time [days]Sample NWM1 2 3 4 5

Content of lactic acid (LA) [weight%]90 41 51 47 50 44180 68 75 74 70 66Content of glycolic acid (GA) [weight%]90 8 14 14 13 8180 22 23 24 24 22Content of oligomers [weight%]90 51 35 39 37 48180 10 2 2 6 12

Composition of the water-soluble degradation products

after 90 and 180 days of incubation

The continuous release of lactic and glycolic acids from the PLGA biomaterials studied allows their gradual removal via

biochemical processes and prevents local acidification of the body

HBA-CoA

n

n

HOC* H CH2CCoA

CH3

O

OC* H CH2C

O

CH3 H3C

O

O

-butyrolactone

enzyme initiator

PHB / poly(3-hydroxybutyric acid)

structure

properties

Case study 2: Biodegradable polymeric controlled-release systems

Activation of anionic species Regioselectivity Stereoselectivity Propagation on carboxylate active centers

Z. Jedliński, M. Kowalczuk, W. Główkowski, J. Grobelny, M. Szwarc, Macromolecules, 24 (1991) 349-352

Anionic ROPanionic catalyst

supramolecular catalystactivated by e.g.,

18-crown-6

no polymerization

O

CH3 On

PBL

BL

n

O

O

H3C

PBLBL

Bioactive conjugates for drug delivery systems

Bioactive conjugates for conductive polymers

Bioactive conjugates for cosmetic industry

Bioactive conjugates for agriculture

Bioactive conjugates for compostable packages

DOI: 10.1002/mas.21474

Bioactive conjugates from natural & synthetic PHA

Structural characterization of biocompatible lipoic acid–oligo (3 hydroxybutyrate) ‐ ‐

conjugates by ESI MS

Rapid Communications in Mass Spectrometry, 27 (2013) 773-783

Biomacromolecules, 8 (2007) 1053-1058

International Journal of Mass Spectrometry, 359 (2014) 6-11

Rapid Communications In Mass Spectrometry, 12 (1998) 357-360

p-Coumaric acid–oligo(3-hydroxybutyrate)conjugates

a)

b)

Valilic acid–oligo(3-hydroxybutyrate) conjugates

Designed Monomers and Polymers, 17 (2014) 311-321

Oligo(3-hydroxybutyrate) conjugates with antimicrobial agents

ESI-MS2 spectrum (in positive-ion mode) of a selected sodium adduct

of oligomers [MCPA-(MCPA-CH2-HP)/HB5+Na]+ at

m/z 937

Potentially bioactive (co)oligoesters containing pesticide moieties

Rapid Communications in Mass Spectrometry, 29 (2015) 533-544

M A R G E N

New generation of packagesfrom compostable polymer materials

POIG.01.03.01-00-018/08

The use of environmentally friendly polymers as packaging materials for long shelf-life applications as cosmetic packages is the new trend for production

Polymer Degradation and Stability, 98 (2013) 316-324

Visual evaluation of the PLA film before degradation (A), after 16 weeks (B) and after 24 weeks (C) of degradation in paraffin at 70°C

A B C

IIIII

Changes in GPC chromatogram of PLA samples after 44 weeks of degradation in glycerine, propylene glycol and paraffin at 70°C

The ex-ante investigations as well as ex-post studies are needed in order to define and minimize the potential failure of novel biodegradable polymer products before, during and after specific applications

The ESI-mass spectrum (negative ion-mode) of the remaining PLA film after 1 year incubation in paraffin at 70°C

The most important requirement for plastic cosmetic packages is to avoid degradation and the migration of any low molecular weight components into a cosmetic formulation during storage

Visual evaluation of the PLA and PLA/(R,S)-PHB rigid films

(A) before degradation

(B) after 15 weeks of degradation in paraffin

PHB, % 0 3 9 12 15

CONCLUSION

Both the ex-ante investigations as well as the ex-post studies are needed in order to define and minimize the potential failure of novel polymer products before and after specific applications. It opens a wide opportunities for FEAPM mass spectrometry

”There are no bad materials– just wrong applications” ?

D.W. van Krevelen 1973

Research supported by

NCN DEC-2012/07/B/ST5/00627

POIG.01.03.01-00-007/08-00

THANK YOU FOR YOUR KIND ATTENTION

Artist: Agnieszka Bieniek – Wydrzyńska, Rybotycze, 2012