Team Polymerization

Ryan SyafrinJustin SidebottomDerrek McDonald

Mattias StollKyle Anderson

Bioabsorbable Stent

Application in Biomedical field: as treatment of coronary artery blockages

Polymers: • Poly-L-lactic acid (PLLA) • polyglycolic acid (PGA)• poly (D, L-lactide/glycolide) copolymer

(PDLA) • polycaprolactone (PCL)

http://en.wikipedia.org/wiki/Coronary_stent

Part1

Polycaprolactone (PCL)

Monomer undergoes ring-opening polymerization [1]

Monomer polymer unit

(SciFinder)

Polycaprolactone

• PCL is hydrophobic and semi-crystaline; crystallinity is inversely related to molecular weight in general [1]

• Very biocompatable; used in drug delivery, sutures, and tissue engineering [1]

• Useful in long-term (1 year +) drug delivery [1]– Blended with other polymers to improve release

rates; promising for peptides and proteins

Polycaprolactone

• Used in co-polymers to offer sutures with reduced stiffness [1]

• Promising material for tissue engineering [1]– Interesting potential for bone regrowth scaffolds;

may use tricalcium phosphate additives to improve mechanical properties, biocompatability, and osteoconductivity [2]

Applied Plastics Engineering Handbook

• Major producers include Dow Chemical, Solvay, and Daicel Chemical.

• Trade name: TONE and CAPA

Polycaprolactone

• Properties highly depend on molecular weight.

• Found as a waxy solid or totally solid polymer depending on molecular weight.

Properties PCL 1 PLC 2 PLC 3

Molecular Weight 37000 50000 80000

Melting Point (°C) 58-60 58-60 60-62

Tensile Stress (kg/cm^2) 140 360 580

Elongation at Break (%) 660 800 900

Polycaprolactone

• Waxy PCL is most commonly used as an additive.• PCL is often blended with other polymers like PP,

polycarbonate, poly ethylene oxide, and starch.• Exhibits high-molecular-chain flexibility and processability.

– Can be spun into fiber or blown in to films with little thermal degradation at temperatures less than 200 °C.

• Draw back is the low melting point and glass transition temp: -60 and 60 °C.

• Used for food packing and tissue engineering.– Microcellular PCL foams are used for tissue regeneration and

cell transplants.

Self-Lock Drug-ElutingPolycaprolactone

Stents

Stent coated with paclitaxel with a spray coating No significant weight loss after time passage or when the pressure was reduced

Part2What SciFinder/handbooks/Internet did well

Media Did Well Did ok Did bad

Handbook Described uses and applicability. PCL PropertiesWhere it comes from

Explaining how structure influences properties.

Specific examples of the product in use.

SciFinder Gave specific and general examples of product uses; listed properties and reactions.

Explaining how structure influences properties.

Article relevance and accessibility varied; required significant digging and sorting.

Internet Source

Provided many general information. Sources varies from journals, articles, personal blogs, wikipedia, etc.

Explaining the applications and pictures of a particular polymer.

Information obtained can not be fully trusted without further research to confirm its validity.

Colgate Triple Action

Part 3

Ingredients purpose toxicity

sodium fluoride enhance the strength of teeth by the formation of fluorapatite

toxic and irritant

sorbitol thickener and sweetener

Classified as safe

water base material Classified as safe

hydrated silica fine gel abrasive Classified as safe

sodium lauryl sulfate foaming agent, which enables uniform distribution of toothpaste

skin and eye irritation

Ingredients purpose toxicity

Polyethylene glycol-12 dispersant PEGs contain potential toxic impurities. PEGs are nephrotoxic to skin

tetrasodium pyrophosphate

prevent calcium and magnesium from depositing on the teeth

twice as toxic as table salt when consumed orally

sodium saccharin sweetener Classified as safe, but it can cause cancer

xanthan gum binder to make the toothpaste uniform

Classified as safe

titanium dioxide white color Classified as safe

Flavors and color Taste and appearance safe

ReferencesM.A. Woodruff and D.W. Hutmacher, The return of a forgotten polymer-Polycaprolactone in the 21st century. Progress in Polymer Science (2010), 35, (10), 1217-1256. Elsevier Ltd.Found with SciFinder on 9/21/2011. Article link: http://www.sciencedirect.com/science/article/pii/S0079670010000419#sec5 C.X.F. Lam, S.H. Teoh and D.W. Hutmacher, Comparison of the degradation of polycaprolactone and polycaprolactone-(beta-tricalcium phosphate) scaffolds in alkaline medium. Polymer International, 56 (2007), pp. 718–728. doi: 10.1002/pi.2195Referenced by [1]; found on 9/21/2011. Article link:http://onlinelibrary.wiley.com/doi/10.1002/pi.2195/full Kutz, Myer. Applied Plastics Engineering Handbook: Processing and Materials. Amsterdam Boston, Mass: William Andrew, 2001.