Acrylic Resins are derived from methacrylic acid, acrylic acid or other related compounds, these substances are related to thermosetting plastic or thermoplastic. For textile, lacquer finishes and adhesives Polymethyl Acrylate is used. Polymethyl Acrylate is an acrylic resin but in an emulsed form. If mixed with clay Polymethyl Acrylate can be used to gloss paper. Polymethyl Methacrylate is another Acrylic Resin which has a different use, it is used to make hard plastics, these hard plastics however have light transmitting properties.
Polymethyl Methacrylate (PMMA) is a transparent plastic and a thermoplastic, in chemical terms PMMA is the synthetic polymer of methyl methacrylate, when sold it goes by many different trade names, theses are:
Limacryl, Per-Clax, Plexiglas, R-Cast, Vitroflex, Altuglas, Perspex, Arcylex, Plazcryl, Acrylite, Polycast, Acryplast, Optix, Oroglass and Lucite and is commonly known as Perspex or Plexiglas (Acrylic Glass)
Polymethyl Acrylate (PMA) is the polymer of methyl acrylate; it is very similar to PMMA except PMA lacks the methyl groups that are on the backbone of the carbon chain. Because PMA’s polymer chains are smoother and thinner than that of PMMA’s, PMA becomes a soft rubbery white material. Die to the length and smoothness of the chains they are able to slide easily past eachother.
So What Actually is Acrylic Resin?
Acrylic Resin is the general term that is used to describe a monomer that has had heat and polymerization applied to it, this chemical reaction creates many different types of plastics (resins) and Acrylic Resin is the general term given to these plastics.
PMMA (Polymethyl Methacrylate) is the chemical term given to the resin produced from MMA (Methyl Methacrylate Monomer). MMA is a colourless and transparent fluid substance, high transparency is one the main characteristic features of PMMA. PMMA has a very high weather resistance sunlight does not easily turn it yellow or make it crumble. Polymethyl Methacrylate are used for windows in aquariums that rely on transparency, but this is not their only use, they can be used for various other items like Taillights of a vehicle, backlight optical waveguides that are used for LCD (Liquid Crystal Display), Signboards that are used in shops like a convenience store, Mobile Phone display screens and many more.
Acrylic Resin is a thermoplastic with glassy properties, it can be moulded and cast or used in adhesives and coatings.
Synthetic Resin – This resin has a polymeric structure, it is used mainly in plastics and is a resin in its pure state.
Acrilan, Polypropenonitrile – This resin has the trade name of Acrilan, it is an Acrylic Resin used to make strong but soft crease-resistant fabrics.
Polymethyl Methacrylate – This is the Acrylic Resin that has been stated above, the transparent plastic that can be used suitably as glass.
In summery Acrylic Resin can be any of numerous thermosetting or thermoplastic copolymers or polymers of methacrylic acid, acrylonitrile, acrylic acid or esters of these acids. It has many uses like to produce paints, lightweight plastics, synthetic rubbers and adhesives.
How to cut perspex using a circular saw and a jigsaw. Brought to you by www.ultimatehandyman.co.uk
One of K2′s 1000 watt Penta lasers cutting through cast acrylic sheet. www.k2a.co.uk
What are plastics?
Plastics as we broadly understand it today are synthetic or semi synthetic products or raw materials, formed by polymerisation, and are largely derived from oil. Polymerisation is the formation of polymers i.e. repeated numbers of smaller structures (monomers) joined together.
It wasn’t until the 1860s that the first semi synthetic materials or plastics were first brought to the attention of the world, and since the development of thermoplastics throughout the 1900s it’s hard to imagine how difficult life would be without plastic. The main reasons why plastics replaced more traditional materials are quite straightforward when you think about them.
What’s so good about plastics?
Plastics are relatively light and very durable. The hundreds of different plastic varieties are ultimately recyclable, although it’s only in recent years that our UK society has begun to take advantage of plastic recycling, often in tandem with our weekly waste collections. Plastics have great thermal and insulating properties (clothes, carpets, bedding etc). Plastics are resistant to many chemicals and water, as well as being very strong.
Most notably though, plastics have proven relatively inexpensive to produce, and are so versatile that they can take on almost any form and colour.
What are the popular types of plastics and what’s the difference between them?
These were developed in the 1930s. Acrylics are particularly resistant to the weather and the sun. Acrylic is particularly effective as ‘clear’ plastics, and transmits light brilliantly. Applications include leaflet holders, signs, display cases, boat windows and point of sale to name but a few.
Often wrongly spelled as Plexiglass, Plexiglas is actually a brand name for a kind of clear thermoplastic resin that’s basically a cross between acrylic and polycarbonate.
First developed in the 1950s, these thermoplastics most popularly have engineering applications. This is due to polycarbonate’s strength coupled with versatility, and its electrical insulating properties. Applications include machine guards, capacitors, gaskets etc.
This is a variety of polycarbonate. It is popularly developed in sheet form and is widely recognised as a kind of ‘clear’ plastic.
Another plastic developed in the 1950s with industrial applications, this is particularly suitable for hot fill packaging because it has low density but is very rigid. Other applications include carpeting and packaging.
Poly Vinyl Chloride (PVC) can be shaped and moulded into an exceptionally wide variety of products. Chemical Plant Industry applications of PVC include water tight tanks, and ducting for Clean Air Systems.
Polyethylene Terephalate Glycol (PETG) is another industrial thermoplastic. Applications include frames, sign holders and point of purchase displays.
How it takes shape
Modern advances in plastic fabrication, moulding, casting, extrusion, thermoforming, cutting, bending, machining, gluing, welding, stamping of sheets, plastic engraving, fibres and solid blocks mean that our imagination provides the only real limitations to what form plastics can take.
If you asked most people, they would be unlikely to know what plastics actually are, and even more unlikely to be able to tell you the difference between the many types. Despite this, plastics are a central and essential part of modern daily life.
Learning how to build a â??Thin-Filmâ? solar cell is very interesting educational project and it helps you get to grips with the photoelectric effect.
What You Need:
â?¢ Copper sheeting
â?¢ Clear Plexiglas/Perspex/acrylic sheeting
â?¢ Some thin wood strip
â?¢ Copper wire
â?¢ Duct tape
â?¢ Metal guillotine (optional)
â?¢ Bandsaw (optional)
â?¢ Tin snips
â?¢ Electric ring hob
First of all, cut a square of the copper sheeting so that it is about 6-8 in. square in size.Â It is much easier to do this with a metal guillotine; however, if you havenâ??t got access to this sort of equipment, tin snips will work just fine.
When you have done this, wash your hands thoroughly and dry them.Â You need to remove any grease or oil from your hands that could cause problems with the next step of the process.Â Remove any grease or detritus from the copper sheeting.Â Next, take a piece of emery cloth, and thoroughly sand down the piece of copper on both sides to remove the top layer of oxidized copper.
This will leave you with nice bright shiny red copper underneath.
You now need to heat treat the copper, in order to form an oxide coating on top.Â It may sound counterintuitive that we have just removed all the oxide and now we are going to put oxide back on, but the oxide coating we will be applying will be a film of â??cuprous oxide.â?
You will need an electric hob to do this. If you have any â??heat proof govesâ? and metal tongs, this might be the time to get them in order to handle the metal while hot.
You need to turn the burner to the highest setting, with the sheet of copper just placed on top. Observe the changes to the copper carefully, they are very interesting.
As you heat the copper, it takes on a lovely vivid patina of different colors.
If you have access to nitric acid, you can use this as a superior method for removing the upper cupric oxide layer.
You will see a black crusty oxide form on top of the copper plate. If you leave the plate to cool slowly, the crusty layer should become fairly fragile and separate easily from the underlying copper. When you have allowed the plate to cool thoroughly, give the plate a firm bang edge-on to a hard surface. Some of the oxide will pop off. Rub the oxide gently with your fingers under a tap, and you will find most of the black layer of oxide comes off easily. If any bits are stubborn, do not under any circumstances scour them, as we do not want to damage the fragile surface.
Under this black layer of oxide, you will find another layer of reddish orange rust color. This is the layer which is â??photosensitiveâ? and will make our thin-film solar cell work.
Make a spacer now from some thin strips of wood. I used duct tape to join my pieces of wood together â?? Do not use metal fixings as they could react electrolytically with the other components of the cell.
We are now going to make another electrode. It has to have the property that it does not touch the other piece of the solar cell, and allows light to hit the surface. We are going to use salt water as our other electrode, making contact with the whole surface of the thin film cell, yet conducting electricity. We are then going to immerse another copper wire to make the connection. You could equally use another piece of copper plate around the outside of the thin-film cell, but not touching our oxidized copper.
In a commercial thin-film cell, tin oxide is commonly used as the other electrode, as it is clear and yet conducts electricity.
Now take a piece of Perspex to act as a cover plate, and stick a strip of duct tape on either side.
We are going to stick our other electrode wire to this piece of Perspex.
Remember to use thickish wire for clarity, with few actual zigzags so that you can clearly see what is going on. To optimize the performance of your solar cell, you want to make the conductor large. To this end, you are better using lots of thinner gauge wire in a much finer zigzag pattern-this will still allow the light to get through, but at the same time gives a large conductor area.
You can experiment with different types of wire And copper â?? The trick is to try and maximize the surface area of the copper, while trying to block as little light as possible from reaching the solar cell.
Fold the duct tape over and stick the wire to the plate.
We are now going to combine the electrode plate with the space. Again, duct tape makes this a nice easy job.
Next, we are going to take the copper plate, and stick duct tape to one side, with the sticky side of the tape facing the same direction as the layer of red copper oxide.
Combine the plate and the front module to make the finished solar cell.
Now, take a little salt water, and fill the void between the Perspex front section and the copper plate.Â Seal the module with duct tape all round to prevent leakage.
Finally, connect your module to a multimeter, find a bright light source, and explore some of the electrical properties of your solar cell.