Isotactic Polybutene Granules from China
Isotactic polybutene granules, a stereoregular polymer of butene with high crystallinity, fall under HTS 3902.90.0050 as 'other' primary olefin polymers (>95% butene content). Used in films and molded parts for its strength and chemical resistance. Classified per note (a)(1) for named poly- prefixes.
Duty Rate — China → United States
44%
Rate breakdown
9903.88.0225%Except as provided in headings 9903.88.12, 9903.88.17, 9903.88.20, 9903.88.54, 9903.88.59, 9903.88.61, 9903.88.63, 9903.88.66, 9903.88.67, 9903.88.68, 9903.88.69, or 9903.88.70, articles the product of China, as provided for in U.S. note 20(c) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(d)
9903.05.3112.5%Section 301 (forced labor) — additional 12.5% ad valorem on products of China
Import Tips
• Include stereochemistry details in technical data sheets for CBP review
• Segregate from polyethylene shipments to prevent co-mingling errors
• Watch for moisture content affecting primary form integrity