Polypropylene (PP) is a thermoplastic polymer extensively utilized for its resistance to chemicals, heat, and impact. Its molecular structure, predominantly nonpolar, inherently makes it an electrical insulator rather than a conductor. Consequently, the electrical conductivity of pure polypropylene is extremely low, often in the range of 10^-14 to 10^-17 S/m (Siemens per meter), which is characteristic of most non-conductive polymers. This low conductivity is due to the absence of free electrons or ions that can move freely through the material, which is necessary for electrical conduction. However, the conductivity can be significantly increased by incorporating conductive fillers such as carbon black, carbon nanotubes, or metal fibers into the polymer matrix, tailoring the material for specific applications requiring electrical conductivity.

Polypropylene card sleeves, popular for protecting collectible cards, do have a tendency to split under certain conditions. These sleeves, made from a type of plastic known as polypropylene, are valued for their clarity and durability but may not always withstand rough handling or excessive use. The material's flexibility allows it to bend without damaging the card inside, yet its plastic edges can split if overstretched or if the card is forced into the sleeve improperly. The likelihood of splitting can also vary depending on the thickness and quality of the sleeve; thicker, premium-quality sleeves are generally more resistant to splitting. To minimize the risk, it's important to handle these sleeves gently and ensure that cards are inserted straight and without forcing. In cases where utmost protection is required, it might be worth investing in higher-quality or thicker sleeves despite their higher price.

Batik yarn refers to a type of yarn that has been dyed using the traditional batik dyeing process, which involves creating patterns on fabric by applying wax to protect certain areas from dye. This method results in the yarn having a vibrant, multi-colored, and often variegated pattern, similar to the intricate designs seen in batik fabric. The wax-resist dyeing technique ensures that no two batik yarns are exactly the same, lending a unique, handcrafted feel to knitting or crocheting projects. Batik yarn is popular among crafters seeking to add a touch of distinctive color and pattern to their work, suitable for making garments, accessories, and home decor items. It’s worth noting that the quality and characteristics of batik yarn can vary depending on the materials used (such as cotton, silk, or wool) and the specific methods employed by the artisans.