Polycarbonate
Contents
Intro
Polycarbonate is a polymer of carbonate (–O–(C=O)–O–) containing molecules and is a versatile plastic. Polycarbonates have good optical and extrusion properties. Polycarbonate can be produced from a variety of monomers of synthetic or organic origin. Current industrial production is based up bisphenol-A (BPA), but there are concerns released monomers act as an endocrine disrupter. Other sources derived from fluoroaliphatic compounds, or alcohol and esters are also possible and organic monomers would allow local production of feedstocks. Sugars have been incorporated into polycarbonates and high performance bio-polycarbonates are starting to be produced. Research and development of an open source process for polycarbonate production from local feedstocks would benefit the OSE product ecology.
Industry Standard Installation
R Value
- 1.5 for twin wall, 6 mm, and 1.7 for 8 mm, compared to 1 for glass. R=3 for five-wall polycarbonate. [1].
- 1.9 for twin wall, 10 mm.
Strategy
Since Double wall polycarbonate is $1.5/sf (R=1.5) and five-wall (R=3) is $5/sf, it is more cost effective to do 2 layers of double wall polycarbonate than a single five-wall system. 2 layers will get us R=4.5 - since an isulating cavity is created between the 2 layers.
Energy savings - if we assume a greenhouse surface of 47 4x8 panels - 1504 square feet. BTU loss is on average 40 degree difference per square foot per hour - with 24 hours for 120 days. 6 lb of wood's energy is lost per hour. This means 17,000 lb per season. About 12,000 lb of wood if R=1.5. 4000 lb wood if R=4.5. Saves 8000 lb of fuel, or 2 cords of wood, so $500 saved per year. 4 or 5 year payback on greenhouse insulation.
Patents
Patent for the production of carbonates from a B-fluoroalcohol, carbon monoxide, a group VIIIb, an electrolyte containing bromide, chloride, or iodide ion and a direct electric current.
Patent for the production of polycarbonate from a B-fluoroaliphatic carbonate with a polyfunctional alcohol or phenol. This reaction uses the basic properties of the B-fluoroaliphatic carbonate to catalyze the reaction. Previous methods used base catalyst for polymerization of aliphatic carbonic acid, or aromatic disesters with multifunctional alcohols.
Patent for the production of low weight polycarbonates from sugars suitable for use as lubricating and refrigerant oil.
Patent dealing with improved mold release of polycarbonate
- http://130.34.101.249/english/report/repo1997/97c02.pdf
- http://www.poly.edu/grossbiocat/_doc/publication/Macromolecules%202003,%2036,%209804-9808.pdf
Sourcing
- Weight: 10 mm is .45 lb/sf - [2]
Multiwall
- Menards - $60 for 32 sf = about $2/sf
- Regal Plastic - [3]
- They carry 35 mm plastic - [4]
- Standard is 6 mm, $1.50/sf, 8 mm = $1.92, 10 mm = $2.29. $5 per cut from manufacturer. $75/hour for cutting in house. $3-400 for 2000 sf shipping from NC; shamsa - swalker@regalplastic.com. Standard 8-12-16-22 foot length. $12/linear foot for crating.
- $2/sf - [5]
- $1.5/sf - [6]. Price here is the same for 8 mm, and $2 for 10 mm, $3 for 16 mm, and $5 for 25 mm (triple wall).
Open Source Microfactory
- Print using a high temperature printer enclosure for 3' wide panels or 4' wide
- At $1/lb commercial resin - $16 per 4'x8' panel
- At $0.1/lb post-consumer resin - $2 per panel.
See Also
Useful Links
- Installing multiwall polycarbonate, from Sundance - [7]
