Sinopec Ethylene Vinyl Alcohol Copolymer, commonly called EVOH, comes from the chemical reaction between ethylene and vinyl alcohol. Manufacturers use this copolymer because it blocks gases impressively well, working several times better than many standard plastics. EVOH usually appears in the form of solid beads, flakes, or powder, though sometimes you find it as granules or in solution. Each of these forms serves different needs depending on what a project calls for. At the molecular level, EVOH’s repeat structure intertwines ethylene and vinyl alcohol, creating strong bonds that resist both moisture and gases. The typical chemical formula looks like (C2H4)m-(C2H3O)n, reflecting the ethylene and vinyl alcohol units linking together.
Most EVOH grades from Sinopec carry a density around 1.1 to 1.2 grams per cubic centimeter, and a melt flow index between 2 to 10 g/10min, depending on the vinyl alcohol content and the intended end use. In daily handling, EVOH feels smooth to the touch and sometimes waxy. As flakes, it pours easily and blends well with other polymers. Some people compare its appearance to tiny, clear crystals or off-white powder. Shelves in many material labs list EVOH in both bulk and specialty forms, with product codes set up to keep track of molecular weights or vinyl alcohol ratios. Standard packages range from 25-kilogram bags to bulk containers. The harmonized system (HS) Code for this material stands at 390530, covering copolymers of ethylene and vinyl alcohol. Most customs agencies use this identification for tracking imports and exports.
EVOH’s backbone brings together the flexibility of ethylene with the barrier properties of vinyl alcohol. This structure limits gas migration and reduces the passage of oxygen—a real advantage for keeping food fresh or for making multilayer fuel tanks. The polymer’s crystallinity sits midway between fully amorphous and highly crystalline plastics, offering a fine balance between rigidity and processability. EVOH dissolves in certain alcohols and acids, but not in water at room temperature. It softens at higher temperatures, usually above 170°C, which works well in processes like extrusion and injection molding. The unique mix of hydrophilic and hydrophobic segments in the chain creates a film that clings tightly together and seals off oxygen, carbon dioxide, and organic vapors. Downstream industries count on this material for its predictable melting point, toughness, and resistance to oils and solvents.
On safety data sheets, Sinopec’s EVOH appears as a solid chemical with low volatility, not classified as hazardous under global transport regulations. Handling bulk powder or flakes during production stirs up some dust, so common-sense measures like dust masks, goggles, and local ventilation really matter. Material safety studies show EVOH itself brings no acute toxicity by inhalation, ingestion, or skin contact. Chronic exposure hasn’t turned up significant health concerns, but people in the field know to respect workplace exposure limits for dust. The polymer does not raise flagging levels of hazardous chemicals listed under REACH, OSHA, or GHS. Fire fighters tackle EVOH flames with water spray, foam, or dry chemicals; burning the polymer produces carbon oxides but not chlorinated fumes. No evidence has shown EVOH to be a bioaccumulative pollutant, and most waste streams from its processing get collected for either controlled disposal or recycling. Storage recommendations call for a dry environment away from strong oxidizers. Simple palletization works for bags, while larger volumes use lined bins or silos. Spills clean up easily with sweeping and dust suppression. So, the risk profile stays close to that of other commodity thermoplastics.
EVOH ranks high on the list for packaging people who want to keep flavors or aromas inside and oxygen out. Think ketchup bottles, ready-to-eat meals, and even medical blister packs—places where freshness or contamination matter. Engineers take advantage of EVOH by layering it between flexible plastics like PE or PP, making affordable, high-barrier films. For fuel tanks and chemical drums, the material’s barrier holds down emissions and meets tough standards. Some research teams blend EVOH with starches or polyesters to make biodegradable plastics for more sustainable use. The raw materials, ethylene and vinyl acetate, come from petrochemical crackers or fermentation sources. Ethylene gives flexibility, while vinyl alcohol (via hydrolyzed vinyl acetate) brings the blocking power. Suppliers often include processing aids to help melt the copolymer cleanly on standard equipment. As demand grows for longer shelf lives and lower emissions, EVOH’s significance goes up too.
Many companies keep an eye on balancing cost and performance when choosing EVOH. Fluctuations in raw material pricing or resin supply sometimes push packaging teams to rethink their formulations. Technologies that use thinner barrier layers help save on cost and reduce overall plastic use without losing function. The ongoing development of more efficient compounding and blending methods may raise EVOH’s recyclability—which, for now, often gets limited by multilayer structures that resist separation. Materials scientists continue looking for advanced compatibilizers to improve sorting and reprocessing of used films. Health and safety pros in the workplace stress real training, not just binder reviews, so that people spot potential exposure and troubleshoot problems on the shop floor. Governments around the world ask for transparent reporting of chemical ingredients so that customers know what sits in their food containers or medicine packs. Clear labeling with molecular structure, density, and safety data helps buyers make smart decisions and comply with trade standards.
