For questions relating to the structures, properties, production methods and potential hazards of polymer materials commonly known as plastics

learn more… | top users | synonyms

0
votes
2answers
25 views

Which is stronger, PET or PVC?

I have been given the task of designing a new wheel rim (the metal part of the wheel) but instead of metal, it has to be made out of a polymer. I'm thinking of using either PVC or PET but I don't ...
3
votes
0answers
26 views

Why don't you see rigid PET extrusions?

So, I'm confused about something. Rigid plastic extrusions for outdoor applications, such as twinwall greenhouse panels and the like, are most commonly polycarbonate. They're next most common ...
1
vote
1answer
23 views

Polysytrene factories and hypothetical health concerns [closed]

Background/Research so far I'm actually not much of a chemist at all; but I'm doing research for a book I'm writing. The events of the story begin from a factory that produces/supplies jewel cases ...
1
vote
0answers
30 views

What is the name of the crinkly plastic used in clear parts of envelopes?

I've always wondered what it is, as it makes a lot of noise on being deformed. No other common plastic that I've come across has quite the same properties.
0
votes
0answers
13 views

Testing plastics for autoclave

I'm wondering if my glass bottle with a plastic cap can be autoclaved. The cap doesn't have any labels on it. It floats on water so probably it's PP, HDPE or LDPE, but how do I test if I can put it in ...
3
votes
1answer
52 views

Etching ITO on PET without damage

I am planning to use some of this to construct a transparent touch panel for a prototype of mine. It is PET plastic coated in Indium Tin Oxide. My plan is as follows: Use some of this UV-cure dry ...
2
votes
1answer
68 views

What is inhibiting polystyrene's ability to dissolve in traditional solvents like ethanol or acetone?

My friend and I have been struggling with this problem for a couple days. Because polystyrene has a similar structure to many plastics, we assumed that it would dissolve in acetone. However, after ...
0
votes
0answers
30 views

Does the plastic cup PETE 1 material leak toxic material if subject to boiling water even for part of a minute?

Sometimes a cafe may pour boiling tea into a plastic cup made of PETE 1 and then add lemon and cold water / ice to it. When the cup is handed to the customer, the cup looks ok. And I suppose even if ...
1
vote
1answer
81 views

Supermarket HDPE plastic bags safety

Supermarket plastic bags are made of high density polyethylene, and I am interested in the decomposition products at high temperature: what type of compounds are released and how dangerous are they? I ...
3
votes
0answers
25 views

Why does plastic tear easier when you pull it quickly?

If you've ever taken the plastic from a plastic bag and pulled on it, you might know what I mean. If you pull quickly, the plastic tears relatively easily, but if you pull it slowly, it gets stretched ...
1
vote
1answer
32 views

Hazards of Keeping Freshwater Fish in a Container that was Used for Adipic Acid

I have an Intermediate Bulk Container (IBC) which is a large 3' x 3'x 3' plastic cube. The label on the container described it as storing Adipic Acid. Is it safe to use this container to grow plant ...
1
vote
0answers
47 views

Are plastics lipophilic/oleophilic? [closed]

I have found several, not-so-reliable Google sources saying that plastics are lipophilic. I was wondering if anybody could confirm this, or is anybody might be able to point me towards a peer-...
4
votes
1answer
105 views

Why plastic sheets contract when heated?

Why do thin plastic sheets contract when heated, contradictory to the behavior of most other materials ? What are the things going on at the molecular level ?
0
votes
0answers
12 views

How biodegradable is PLA?

Supposed I want to 3D print some items for use in my garden, and my options are ABS and PLA plastics. PLA is supposedly biodegradable, but I prefer printing with it over ABS. I don't want my plant ...
1
vote
0answers
51 views

Diffusion into PMMA

My thesis is about effect of cigarette smoke to PMMA polymer, apparently cigarette smoke have some amount of eugenol which is mildly acidic and they will evaporate when the cigarette is burned. In ...
4
votes
1answer
82 views

At what temperature do complex hydrocarbons become ashes?

When heating a metal tube with polypropelene in it, i found that i still had brittle black foam and flakes in it even though it had been in a blue flame at around 500'C What happens to complex ...
0
votes
0answers
43 views

Can we modify plastic to cool things?

I have very little chemistry background and I have a project that I'm working on about smart plastics. My question is: Can you chemically modify plastics so that you can make it into a regular one-...
3
votes
0answers
52 views

What's causing my plastic fork to break?

This has been a real mystery for me at work. For the past three days I've eaten salads for lunch. I used a plastic bowl with a lid and when I was finished with the salad, I didn't rinse out the bowl ...
2
votes
1answer
33 views

Biodegradation time for biodegradable shopping bags?

How long does it take for the plastic/polythene shopping bags marked biodegradable to biodegrade?
3
votes
1answer
67 views

Urea-Formaldehyde cleanup

I work a lot with Urea-Formaldehyde resin/plastic, both in carpentry and textiles. Cleanup while still uncured is simple enough. Cleanup before even mixed is easy enough. What I don't know, is how to ...
4
votes
1answer
68 views

What is a food-safe level of exposure of plastic containers to heat?

There are many articles about how heat can trigger the release of potentially harmful carcinogens from plastic containers into the food or liquid they contain. Specifics they fail to mention, though, ...
0
votes
0answers
35 views

Cured epoxy remover

I have plastic extrusion plant, we are plastic granule producers. Actually I want to remove filler sand which is mixed with epoxy in cfl bulb plastic cabinet. In cfl lower portion to fix filaments ...
1
vote
0answers
155 views

What is the transparent film that covers water-soluble dishwasher tablets?

These dishwasher tablets (Finish Powerball Shine) seem to be covered in plastic! But that can't possibly be true since there's no unwrapping, and they're completely soluble in water. What is the ...
0
votes
1answer
54 views

Do melt flow rate and density tell you everything about pure HDPE?

I understand that melt flow rate and density can be used to classify HDPE. Does this mean that if I have the melt flow rate and density of an HDPE (with no additives), then I can know its other ...
3
votes
1answer
163 views

Plastic membrane that lets water in from the outside only?

I'm looking for a type of plastic membrane that would let water through it from the outside, but wouldn't allow water to escape once it's inside the membrane. Ideally available in a roll. Does such ...
4
votes
1answer
755 views

How does the catalyst in a polyester resin or epoxy work?

I would like to understand how the polyester resin or epoxy catalyst works and to what degree it must be mixed with the base material in order to be effective. Typical product instructions advise to ...
3
votes
3answers
262 views

Can Polyethylene Dissolve on 50-60 °C

I know that polyethylene's melting point is between 115–135 °C, however I would like to know if can it start dissolving between 50-60 °C? In a real example, if I put warm food (straight from the ...
3
votes
1answer
155 views

Polyurethane epoxy resin chemistry advice please?

My friend can buy polyurethane epoxy from his workplace for 3 dollars a litre, except that he doesn't know precisely the data sheet for it. His factory gets it in 20 ton deliveries. He says that the ...
16
votes
2answers
607 views

Ripping apart a polymer - reaction or not?

I was holding a piece of plastic earlier, and I ripped it in half. This caused me to start to think about what was happening at the atomic level. If the plastic is being ripped, clearly bonds are ...
3
votes
1answer
288 views

Which plastic type is used inside dishwashers?

We have a drinking bottle made partly from polypropylene that wraps when washed in a dishwasher. We would like to change the plastic type so that it can withstand in dishwasher. I know for a fact ...
7
votes
1answer
467 views

Why/how do cloves break down plastic?

When my family buys powdered cloves in bulk, we put them in plastic until we get home - which takes at very most an hour. As soon as we get home, we transfer them into glass because we have had issues ...
6
votes
2answers
3k views

Why does alcohol crack acrylic (plexiglass)?

I have seen videos and discussions about alcohol cracking acrylic, and waterblock manufacturers reminding users to not use alcohol in cooling system with plexiglass acrylic, but why is it so? That ...
2
votes
1answer
83 views

Thermal decomposition products of polyurea?

Are the thermal decomposition products of polyurea polymers known, especially of the urea group, in the absence of water? Looking at the formula ...
3
votes
0answers
166 views

Chemistry of Stripper Poles: How much weight can different materials support? [closed]

I'm looking to create a light up dancing pole. This requires a translucent material that is strong enough to support the weight and force of a human being, even when it's hollowed out to so LEDs can ...
4
votes
3answers
330 views

Can plastic leak into water from a HDPE “2” plastic container at room temperature?

Here in USA supermarkets often sell water in plastic 1 gallon jugs. These jugs seem to all be stamped with the text "HDPE" (meaning that the material is High-density polyethylene) and a resin number ...
1
vote
0answers
72 views

Resin for making Jewelry

I want to make resin jewelry, but I'm having problems! I want to create that effect, but I do not know what materials to use The result is a mix of resin and other such things
1
vote
1answer
52 views

Which material to use for athletic accessories?

I'm looking for some guidance in selecting the right material for dance shoes heels and women's self-defense accessories. I'm looking for a material that 1) has a superb strength-to-weight ratio, can ...
3
votes
2answers
326 views

Material that doesn't melt at 800 deg F, but can be dissolved?

I'm a sculptor and I have a chemistry/plastic question. I thought here would be a good place to ask. I'm looking for a substance (probably a plastic) that has these characteristics: Doesn't melt at ...
3
votes
1answer
149 views

The walls of a plastic vial with Mercury inside are darkening. What is causing this?

I have a sample of Mercury in a plastic vial, The vial is a BD Vacutainer (genuine), made of polyethylene terephthalate. It is used for blood samples, and the one I used was new. When the vial was ...
14
votes
2answers
3k views

Why do many transparent plastics turn opaque when deformed?

Many transparent plastic materials, rigid or not, turn opaque (white) when subjected to stress, deformations or when folded (if not rigid) . The effect seems to be irreversible. What is the cause? ...
2
votes
1answer
112 views

Taiwan propylene explosions one week ago

Is it wrong way to use WATER to relieve the big disaster(propylene leak). What is a better way to relieve propylene leak in a street about large area? Any possible choice to prevent explosion?
5
votes
3answers
5k views

What is the plastic material of the CD cases?

What is the material of which the transparent part of CD cases are made of? It is nicely rigid and really lightweight.
2
votes
1answer
380 views

What is relationship between molecular weight distribution of PE and its strength?

I'm trying to figure out the relationship between the molecular weight distribution of a polyethylene plastic and its strength and heat sealability. (The molecular weight distribution is described ...
3
votes
1answer
144 views

What is this red substance that has accumulated at the bottom of a plastic bottle full of petrol (see picture)?

About two weeks ago I put some ordinary unleaded petrol into a plastic water bottle, as a temporary measure (long story, don't ask!). It has now formed a reddish liquid at the bottom of the bottle. ...
1
vote
2answers
160 views

What is Bisphenol A used for?

I am trying to find out what BPA is used for in the industrial production of plastics. On sources such as Wikipedia I only found the information that it is used, but not why. What are the advantages ...
3
votes
2answers
34k views

Are all PP(Polypropylene), i.e. resin code 5 plastics, safe for microwave and steaming?

If a plastic is marked PP as in Polypropylene (i.e. resin code 5) http://en.wikipedia.org/wiki/Resin_identification_code Is it automatically safe for steaming and microwaving, such that it wouldn'...
2
votes
0answers
64 views

Can TBE electrophoresis buffer be stored in a PETE container?

I'm doing a science project on agarose gel electrophoresis and would like to know if it is safe to store Tris/Borate/EDTA buffer solution inside a PETE container since I will be making about 10L of ...
3
votes
1answer
1k views

Decomposition products of PET

On Wikipedia, it says that polyethylene terephthalate (PET) decomposes at temperatures above 350°C. What are these decomposition products? I read further that acetaldehyde is produced, but is that ...
4
votes
1answer
135 views

Plastics for food packaging

There are many types of plastics that can be used for food packaging, for example: Polyethylene terephthalate (PET) Polyethylene (PE) Polyvinyl chloride (PVC) Polypropylene (PP) What are the ...
1
vote
0answers
450 views

What are Thermoplastic Elastomers (TPE) and what is their environmental impact [closed]

TPE is often touted as a more environmental alternative to PVC (at least for yoga mats). What are TPEs and what raw materials are they manufactured from. What uses and properties do they have? Are ...