Copolymer polypropylene resists dimethylformamide (DMF) at room temperature, and DMF does not dissolve it under any ordinary condition. Every chemical-resistance chart converges on the same cell: PP rates “resistant” to DMF at 20 °C, with negligible absorption on a one-month…
Order a “block copolymer of ethylene and propylene” and the datasheet describes an opaque, tough resin — not the clear, sequential di-block the name suggests. The phrase is a commercial naming convention, not a description of the chain. What you…
Acetal copolymer (POM-C) and polypropylene (PP) both list a maximum service temperature near 100 °C. Yet under a 1.8 MPa load, POM-C holds its shape to about 110 °C while PP softens at roughly 55 °C — half the number.…
Random and impact copolymer polypropylene run the same reactor train up to one decision. Either ethylene gets co-fed into the main loop, or a second gas-phase reactor is added downstream to grow a rubber phase inside the finished homopolymer. That…
“Homopolymer” is one word on a PP quote that locks in a property window before you read any other number. It tells you the chain is built from a single monomer — propylene only, no comonomer disrupting the regularity. That…
A GPPS spec sheet hands you about ten numbers, and four of them decide whether the resin fits your part. Melt flow index sets the molding window. Vicat softening sets the service-temperature ceiling. Notched Izod tells you whether the part…
A PP COA might list “1500 ppm phenolic AO + 1000 ppm phosphite + 500 ppm slip” and look like a complete additive package. Whether those numbers are correct depends on whether the grade is heading into a hot-water pipe,…
A 25 kg bag of PP pellets received last September is not “last September old.” The producer date stamped on the COA is the real starting point. That date is often 60-90 days earlier than the day the container cleared…
A procurement buyer drafting a PP spec for a food-contact pipe extrusion line reaches for a side-by-side virgin vs recycled comparison, expecting impact and price to decide it. The comparison stalls in the regulatory column before either number gets a…
A buyer reading “virgin PP” on a producer spec sheet usually treats it as a chemistry claim. Operationally it is a documentation state — producer-lot traceable, generation zero, no regrind blend-back. The label is shorthand for a paper trail, not…