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[Arbutus]

I was researching adhesives for plastics, but couldn't quite find the correct terminology, so I asked my AI buddy: (warning: Long Read)

what is the correct term for an 'oily' plastic vs a 'dry' plastic? as it relates to the surface properties

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ChatGPT
Reasoned about oily and dry plastics for 1m 1s
Exploring terminology
I’m thinking about the terms "oleophilic" and "hydrophobic" to describe plastics' surface properties, like their wetting behavior or surface energy.
Investigating surface energy
I'm thinking through how "oily" plastic might mean low surface energy, repelling water and attracting nonpolar liquids. Conversely, "dry" plastic might mean high surface energy, favoring hydrophilicity.
Understanding surface properties
"Oily" plastic usually means low surface energy, while "dry" plastic often means high surface energy, reflecting properties like water repellency and nonpolar attraction.
Clarifying plastic terminology
I'm noting that "oily" plastics typically exhibit low surface energy and are nonpolar or oleophilic, while "dry" plastics often have high surface energy and are hydrophilic or oleophobic.
Assessing surface characteristics
OK, let me see. An oily plastic has low surface energy due to surface plasticizers, while a dry plastic has high surface energy and doesn't show blooming.
Clarifying plastic surface properties
I’m noticing that "oily" plastics have low surface energy and are non-polar, while "dry" plastics have high surface energy and are polar. This distinction is crucial for accurate description.
Clarifying plastic archetypes
OK, let's break this down: "Oily" plastics, with their low surface energy and non-polar traits, contrast sharply with "dry" plastics' high surface energy and polar characteristics.
Understanding surface dynamics
I'm sorting through terminology: "Oily" plastic often feels smooth due to plasticizer migration, while "dry" plastic has a rougher, more textured feel. This distinction clarifies their properties.
Pinpointing surface affinities
It's becoming clear that "lipophilic" describes oily plastics, while "lipophobic" distinguishes dry ones, highlighting their attraction to non-polar or lipophilic compounds.
Clarifying surface interactions
OK, oily plastics often feel greasy due to migrating plasticizers, while dry plastics have higher surface energy. These distinctions highlight their unique surface properties.
Clarifying surface distinctions
I'm picturing how low surface energy plastics, like polyethylene and polypropylene, feel greasy and don't adhere well to water. Conversely, high surface energy plastics, like polycarbonate or polyamide, are dry and attract water.
Evaluating technical nuances
I'm piecing together that "surface free energy" effectively measures a solid's bond formation with a liquid. Low surface free energy plastics, like polyethylene and polypropylene, often have a greasy feel and are termed "oily."
Focusing on surface energy
Low surface energy plastics are non-polar and "oily," while high surface energy plastics are polar and "dry," showing less oil wetting.
Revisiting surface energy
Now I'm understanding that the correct terms are low surface energy versus high surface energy. Plastics with low surface energy are oleophilic, while those with high surface energy are oleophobic.
Clarifying terminology
I'm gathering info on how low surface energy plastics might be called "waxy" or "greasy," while high surface energy plastics are "dry," emphasizing their interaction with liquids.
Understanding liquid spread
I’m exploring how "oleophilic" and "oleophobic" describe plastic surfaces interacting with non-polar liquids, while "hydrophilic" and "hydrophobic" characterize interactions with water.
Clarifying surface dynamics
I'm distinguishing low surface energy plastics as "oleophilic" and high surface energy plastics as "oleophobic" or "hydrophilic," based on their interactions with oils and water.
Clarifying surface distinctions
I’m thinking through how "oleophilic" describes low surface energy plastics, which attract oils, while "oleophobic" pertains to high energy plastics, which repel oils, with Teflon as a notable example.
Revisiting surface tilling
Materials with low surface energy are non-wetting for water but can still be wetted by oils. This upends the notion of low surface energy equating to oleophobic properties.
Understanding surface interactions
"Oily" plastics, which can attract oils due to low surface energy, contrast with "dry" plastics, which have higher surface energy and repel oils.
Clarifying surface interactions
I’m noting that high surface energy does not imply a "dry" sensation. Some plastics may feel "waxy" and lubricious, highlighting the need for precise surface energy terminology.
Understanding surface energy
Considering "oily" and "dry" plastics, the former suggests low surface energy materials with migrating additives, while the latter likely implies higher surface energy materials.
Revisiting surface properties
I'm pulling together insights on how surface properties, like low surface energy in oily plastics, determine their compatibility with oily substances, while also considering contamination effects.
Understanding surface dynamics
I'm focusing on surface energy and wettability to describe how different plastic types are drawn to oils. Additives migrating to the surface form an oily feel, highlighting surface characteristics.
Analyzing surface properties
I'm thinking through how plastic's surface energy dictates its affinity for oils, with nonpolar surfaces being oleophilic and polar ones being oleophobic.
Analyzing surface dynamics
I’m piecing together how low surface energy in plastics leads to oil attraction, while high surface energy hinders it. This balance shapes their interaction with oily substances.
Clarifying terms
Hm, that's interesting. Plastics with low surface energy, like polypropylene, feel oily and repel water yet still allow oil penetration. High surface energy plastics diverge in their properties.
Noticing surface contrasts
Polyolefins with low surface energy remain nonpolar, repelling water but attracting oils, giving them an oily texture. High surface energy surfaces, rich in polar groups, stay 'dry' and are resistant to oil.
Evaluating surface traits
I’m noting that high surface energy surfaces are often sticky, more wettable by liquids, and differ from the purely 'dry' feeling, which can be misleading.
Reassessing friction dynamics
Interestingly enough, the text states that an 'oily' plastic might have a slick, lubricious texture, typically linked to low friction, while a 'dry' plastic could infer no oil migration to the surface.
Clarifying surface traits
It's interesting to see that 'oily' plastics likely have low friction, while 'dry' plastics might suggest high friction or no oil transfer, with the term "blooming" suggesting additives migration.
Rethinking surface traits
I’m mapping out that 'oily' might indicate low friction or slickness, while 'dry' could hint at high friction or no oil transfer, which needs further clarification.
Clarifying surface traits
I’m noting the terms 'contact angle hysteresis' and 'wetting vs nonwetting surfaces' to refine the differences between 'oily' and 'dry' plastics, focusing on their surface energy properties.
Pinpointing surface traits
OK, let's clarify that 'oily' plastics exhibit low surface energy, resulting in hydrophobicity and oleophilicity, while 'dry' plastics show high surface energy, making them hydrophilic and oleophobic.
Nailing down concepts
OK, let me see. 'Oily' plastics are low surface energy, oleophilic and hydrophobic, while 'dry' plastics have high surface energy, are hydrophilic, and oleophobic.
Differentiating surface traits
Mapping out 'oily' and 'dry' plastics, I’m thinking about how low surface energy in polymers like polyethylene and polypropylene results in high oleophilicity and hydrophobicity, with varying wetting characteristics.
Clarifying plastic traits
I'm differentiating 'oily' and 'dry' plastics based on surface energy. 'Oily' plastics, often low energy, are oleophilic and hydrophobic. 'Dry' plastics, higher energy, are oleophobic, with treatments like reactive plasma or extreme roughness.
Clarifying plastic characteristics
I’m thinking through surface energy distinctions: 'oily' plastics are low surface energy and oleophilic, while 'dry' plastics are high surface energy and oleophobic, with specific examples to illustrate these differences.
Expanding the perspective
Thinking through surface energy nuances, high surface energy signifies oleophobicity, often with specific engineering. Next, I'll investigate if 'dry' implies oleophobicity in polymers.
Assessing surface traits
OK, let’s break this down: low surface energy often means high water contact angles, low oil contact angles, and wetting properties leading to hydrophobicity and oleophilicity in materials like polymers.
When discussing the feel of a plastic in terms of how it interacts with liquids (whether it seems “oily” or “dry”), the key property is its surface free energy. In technical terms:

• An “oily” plastic typically has a low surface energy. Such materials are non‐polar and tend to be oleophilic (i.e. they are readily wetted by low–surface–tension, non–polar liquids such as oils). This is why they may feel greasy or lubricious.
• A “dry” plastic usually has a higher surface energy. These materials are more polar and can be less easily wetted by oils (sometimes described as oleophobic), which contributes to a less slick, more “dry” feel.

Thus, rather than saying “oily” versus “dry” plastic, you’d more precisely describe them as low surface energy (oleophilic) versus high surface energy (often oleophobic) materials.

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Well that wasn't worth the wait!

Interesting reasoning process though. This AI was ChatGPTo3-mini-high which is designed for science, engineering, coding, logic. The response is very different if a generic AI is asked:

ChatGPT said:​

The correct terms for describing "oily" vs. "dry" plastics in terms of surface properties are:

1. Oily Plastic → "Low Surface Energy" (LSE) Plastic
   
   • These plastics are non-polar, meaning they repel water and high-surface-energy substances.
   • They feel slick or greasy because they resist adhesion and are difficult to bond with adhesives, coatings, or inks.
   • Examples: Polypropylene (PP), Polyethylene (PE), Polytetrafluoroethylene (PTFE/Teflon)
   • Sometimes referred to as "self-lubricating" if they have a naturally low coefficient of friction.
2. Dry Plastic → "High Surface Energy" (HSE) Plastic
   
   • These plastics are polar, meaning they attract and hold water or other high-energy substances.
   • They feel drier and often allow for better adhesion of paints, adhesives, and coatings.
   • Examples: Polycarbonate (PC), Acrylic (PMMA), Nylon (PA), ABS, PVC

So, when referring to the surface feel in a technical context:

• LSE (Low Surface Energy) plastics feel "oily."
• HSE (High Surface Energy) plastics feel "dry."

The ChatGPT answer was much more succinct and answered the question.


And that led to the 3M Adhesives references: https://www.3m.com/3M/en_US/bonding-and-assembly-us/applications/material-bonding/lse-plastics where most of my questions were answered.

So far I am quite impressed by some of these systems, but they also provide perfectly reasonable garbage as part of the response, so it really helps if you know enough to be able to filter the answer and question it. Usually, when challenged, the AI will agree that it made a mistake and it will regenerate a response but it can go off topic quickly, particularly when coding.

 

[Susquatch]

Here is what Gemini said for the same question. It's not waaaay better but it is a bit more focussed.

What is the correct term for an 'oily' plastic vs a 'dry' plastic as it relates to the surface properties?

(Only thought about it for 5 seconds or so.)

The terms used to describe the surface properties of plastics, relating to how "oily" or "dry" they feel, are related to **surface energy** and **coefficient of friction**. There isn't one single perfect term, but here's a breakdown:

* **"Oily" Plastic:** This generally indicates a *low surface energy* and potentially a *low coefficient of friction*. These plastics might also be described as:
* **Slippery:** This refers directly to the low coefficient of friction.
* **Low-friction:** A more technical term for slipperiness.
* **Hydrophobic:** If the "oily" feel is due to the plastic repelling water or other liquids. However, hydrophobicity doesn't *always* equate to a slippery feel.

* **"Dry" Plastic:** This suggests a *higher surface energy* and likely a *higher coefficient of friction*. These plastics might be described as:
* **Tacky:** This implies a higher coefficient of friction where the surface tends to "grab" or resist sliding.
* **High-friction:** The technical term.
* **Hydrophilic:** If the "dry" feel is associated with the plastic attracting water or other liquids. Again, this doesn't *always* mean a high coefficient of friction.

**Important Considerations:**

* **Surface Texture:** The *texture* of the plastic also plays a significant role in how it feels. A rough surface can feel "dry" even if the material itself has a relatively low surface energy. Conversely, a very smooth surface can feel "oily" even if the material has a higher surface energy.
* **Additives:** Manufacturers can add substances (like lubricants or surface modifiers) to plastics to intentionally change their surface properties and make them feel more or less "oily."
* **Static Charge:** Sometimes, a plastic might feel "tacky" due to static electricity, which isn't directly related to surface energy or coefficient of friction in the material itself.

**In summary:** While "oily" and "dry" are common descriptive terms, it's more accurate to use terms like *low/high surface energy* and *low/high coefficient of friction* when discussing the surface properties of plastics scientifically or technically. Remember that surface texture and additives can also influence the perceived "feel."