Isotactic polymers can exhibit chirality due to the spatial arrangement of substituents along the polymer chain. In isotactic polymers, all substituents are oriented on the same side, creating a regular, repeatable structure that can be chiral if the substituent itself is chiral. The chirality of such polymers depends on the nature of the substituent groups attached to the main chain. If those substituents are chiral, the isotactic polymer will indeed be chiral. This chirality is crucial for the polymer's properties, affecting its optical activity, melting point, and solubility. Polymers with chiral centers can interact differently with polarized light and may have enantiomers, which are mirror images that cannot be superimposed on each other, playing a significant role in applications such as pharmaceuticals, where the chirality could affect biological activities.

Determining between polypropylene (PP) and polyethylene (PE) can be approached in a few ways due to their physical and chemical differences. First, density is a key factor; PE typically has a lower density compared to PP. This can be tested through a simple float test in water since PE floats (having a density less than 1 g/cm³) and PP may float or sink marginally, being close to water's density. Another method is the melting point test, where PP has a higher melting point (160-170°C) than PE (115-135°C) - this can be observed by applying heat to a sample and noting the temperature at which it starts to deform. Chemical resistance tests can also highlight differences; PP is generally more resistant to chemical wear. However, for precise identification, advanced methods like Fourier Transform Infrared Spectroscopy (FTIR) can be used, which analyze the material's molecular structure, providing a definitive identification.

Plush yarn, often referred to as "velvet yarn" or "chenille yarn," is a soft, thick yarn that resembles the plush fabric used in soft toys and cozy blankets. It's made from synthetic materials like polyester, giving it a luxurious texture that's both warm and lightweight. The yarn's unique structure, featuring a short pile on the surface, provides a velvety feel, making it a favorite for crafting projects aimed at comfort and indulgence, such as baby blankets, hats, and scarves. Plush yarn is easy to work with, making it suitable for both beginners and advanced crafters. However, due to its bulkiness, it's recommended to use larger needles or hooks for optimal results. This yarn variety is appreciated for its ability to create visually appealing and tactilely pleasing projects, offering a touch of luxury to homemade crafts.