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.
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