Page 2 of 2

Re: Materials Science C

Posted: March 3rd, 2018, 8:29 pm
by IcsTam
Tesel wrote:
IcsTam wrote:I'm just going to post a question, if that's alright.

1. What is a copolymer?
2. Describe and differentiate between a random, alternating, block, and graft copolymer.


Yep, my bad.

Answer
1. A copolymer contains multiple different monomer units.
2A. A random copolymer has monomers randomly ordered, e.g. ABAAABBAABABBBAAB.
2B. An alternating copolymer has regularly alternating monomer units, e.g. ABABABAB.
2C. A block copolymer consists of multiple "blocks" which each contain only one type of monomer, e.g. AAAABBBBAAAAABBB.
2D. A graft copolymer has one type of monomer on the main chain and a different type of monomer on the side chains. In other words, one chain is "grafted" onto the other.


Assuming I'm right, I'll just post the next question, to make sure I don't forget.

Describe the "melting process" for:
1. Amorphous thermoplastic polymers.
2. Crystalline thermoplastic polymers.
3. Thermoset polymers.


Amorphous plastics do not have a sharp melting point; rather, regions of the polymer soften as the temperature increases. Crystalline thermoplastic polymers have a sharp melting point and change to a liquid once that point is met fairly quickly. Thermoset polymers do not melt.

Re: Materials Science C

Posted: March 3rd, 2018, 8:50 pm
by Tesel
Yep, well done. I'd reference the glass transition point for amorphous materials on a test.

Re: Materials Science C

Posted: March 3rd, 2018, 8:57 pm
by IcsTam
Describe the function of each of the following: Plasticizer, Filler, Stabilizer, Lubricant.

Re: Materials Science C

Posted: April 8th, 2018, 1:02 pm
by JavaScriptCoder
Well, this forum seems a little dead, so I'll revitalize it.

IcsTam wrote:Describe the function of each of the following: Plasticizer, Filler, Stabilizer, Lubricant.


A plasticizer makes a material less brittle, a filler (name is a bit self-explanatory) fills gaps, a stabilizer prevents the breakdown of an emulsion (from what I've learned liquid-liquid colloids are insanely unstable) and a lubricant decreases friction.

Is it right?

Re: Materials Science C

Posted: April 8th, 2018, 5:46 pm
by IcsTam
JavaScriptCoder wrote:Well, this forum seems a little dead, so I'll revitalize it.

IcsTam wrote:Describe the function of each of the following: Plasticizer, Filler, Stabilizer, Lubricant.


A plasticizer makes a material less brittle, a filler (name is a bit self-explanatory) fills gaps, a stabilizer prevents the breakdown of an emulsion (from what I've learned liquid-liquid colloids are insanely unstable) and a lubricant decreases friction.

Is it right?


So for filler, I would specify that it improves tensile strength and directional stability in the polymer. Otherwise, that's right! Your turn

Re: Materials Science C

Posted: April 8th, 2018, 8:21 pm
by Name
To speed things up can we post and answer simultaneously and if the answer is incorrect, correct them later? Because this thread is going kinda slowly

Re: Materials Science C

Posted: April 9th, 2018, 5:27 am
by IcsTam
Name wrote:To speed things up can we post and answer simultaneously and if the answer is incorrect, correct them later? Because this thread is going kinda slowly


Works for me, I definitely want this to move faster

Re: Materials Science C

Posted: April 9th, 2018, 11:29 am
by JavaScriptCoder
IcsTam wrote:
JavaScriptCoder wrote:Well, this forum seems a little dead, so I'll revitalize it.

IcsTam wrote:Describe the function of each of the following: Plasticizer, Filler, Stabilizer, Lubricant.


A plasticizer makes a material less brittle, a filler (name is a bit self-explanatory) fills gaps, a stabilizer prevents the breakdown of an emulsion (from what I've learned liquid-liquid colloids are insanely unstable) and a lubricant decreases friction.

Is it right?


So for filler, I would specify that it improves tensile strength and directional stability in the polymer. Otherwise, that's right! Your turn


Ok, name this chemical (I think it could be covered in materials science):

Image

Re: Materials Science C

Posted: April 11th, 2018, 12:34 pm
by IcsTam
JavaScriptCoder wrote:
IcsTam wrote:
JavaScriptCoder wrote:Well, this forum seems a little dead, so I'll revitalize it.



A plasticizer makes a material less brittle, a filler (name is a bit self-explanatory) fills gaps, a stabilizer prevents the breakdown of an emulsion (from what I've learned liquid-liquid colloids are insanely unstable) and a lubricant decreases friction.

Is it right?


So for filler, I would specify that it improves tensile strength and directional stability in the polymer. Otherwise, that's right! Your turn


Ok, name this chemical (I think it could be covered in materials science):

Image


Benzoyl Cyanide

Re: Materials Science C

Posted: April 12th, 2018, 11:04 am
by JavaScriptCoder
IcsTam wrote:
JavaScriptCoder wrote:
IcsTam wrote:
So for filler, I would specify that it improves tensile strength and directional stability in the polymer. Otherwise, that's right! Your turn


Ok, name this chemical (I think it could be covered in materials science):

Image


Benzoyl Cyanide


Very well, I'll give that to you. The IUPAC name is technically phenylglyoxylnitrile but it is more commonly known as that. Your turn (make sure to include your question in the answer so it goes faster).

Re: Materials Science C

Posted: April 12th, 2018, 1:08 pm
by IcsTam
Explain the process of free-radical polymerization.

Re: Materials Science C

Posted: April 19th, 2018, 6:25 am
by JavaScriptCoder
IcsTam wrote:Explain the process of free-radical polymerization.


Free-radicals are particles that have unpaired valence electrons. The process of free radical polymerization is like chain-growth polymerization: Free radicals append themselves to the end of the polymer chain.

Next question.
Image.
Name the points on the stress-strain curve (1, 2, 3, 4).

BONUS POINTS:
Image
Which of these curves is most likely to be representative of a thermoplastic polymer? (Getting the images without labels was the hardest part tbh)

Re: Materials Science C

Posted: April 22nd, 2018, 12:15 pm
by IcsTam
JavaScriptCoder wrote:
IcsTam wrote:Explain the process of free-radical polymerization.


Free-radicals are particles that have unpaired valence electrons. The process of free radical polymerization is like chain-growth polymerization: Free radicals append themselves to the end of the polymer chain.

Next question.
Image.
Name the points on the stress-strain curve (1, 2, 3, 4).

BONUS POINTS:
Image
Which of these curves is most likely to be representative of a thermoplastic polymer? (Getting the images without labels was the hardest part tbh)


1 is the material at rest (is there a more precise term for this?). 2 is the yield point. 3 is the ultimate tensile strength. 4 is fracture

BONUS: Red curve is thermoplastic.


Explain what compression and injection molding are and the difference between the two.