PMMA LDPE HDPE
LDPE is softest, HDPE is harder, PMMA is much harder than HDPE
In increasing order, LDPE has the lowest melting point at 221 to 239 degrees Fahrenheit. It is followed by HDPE at 266 degrees Fahrenheit and PPMA at 320 degrees Fahrenheit.
LDPE is Low Density PolyEthylene.HDPE is High Density PolyEthylene.
LDPE , HDPE, LLDPE
You don't specify anything to compare it to. If you mean the difference between LDPE and HDPE, then LDPE has branched chains which pack together loosely, making a softer material. HDPE is firmer because it has unbranched chains which pack together tightly.
LDPE , HDPE, LLDPE
Because LDPE is an abbreviation of Low Density Poly Ethylene, whereas HDPE stands for High Density Poly Ethylene. This means LDPE is less efficiently packed together than HDPE, due to the larger amount of branching found in LDPE, leading to a weaker material.
HDPE has higher density therefore it has greater tensile strength
Usually with a 'rubberizing' additive that contains LLDPE (Linear low density polyethylene) More branches and better bonding, less amorphous. Greater tensile and impact strength than LDPE or HDPE.
High-density polyethylene (HDPE) has a higher density and tensile strength compared to low-density polyethylene (LDPE). This makes HDPE more rigid and resistant to higher temperatures, while LDPE is more flexible and has better impact resistance. HDPE is commonly used for bottles, pipes, and containers, while LDPE is used for packaging films and smaller containers.
Technically, adequately made LDPE and HDPE bags/containers are safe for food storage and consumption. Recycled materials and unsafe additives/colors, etc. must not be added.For instance, LDPE bags are more transparent in nature than HDPE, so it ideal for clear zip-lock sandwich bags. HDPE is tougher and opaquer (UV protection of sensitive foods), so used for milk bottles. Consider factors like barrier, toughness, seal ability before making your purchase.
The enthalpy of high-density polyethylene (HDPE) can vary depending on its specific form and conditions. However, HDPE typically has a heat of fusion enthalpy of around 110 J/g.