Polyethylene Glycol (PEG) is a workhorse polymer in countless industries, prized for its adaptability. A critical factor dictating its performance across applications is its molecular weight. From low-viscosity liquids to high-viscosity solids, the chain length of PEG molecules directly impacts their physical and chemical behaviors. For B2B buyers and formulators, understanding this relationship is key to selecting the right PEG grade for optimal results and cost-efficiency.

At the lower end of the molecular weight spectrum, typically ranging from 200 to 600 g/mol, PEGs are liquids at room temperature. These low molecular weight PEGs are excellent solvents, humectants, and plasticizers. Their strong water solubility and low volatility make them ideal for cosmetic formulations like lotions and creams, acting as moisturizers. In industrial settings, they can be used in inks as solvents and binders, or as hydraulic fluids and plasticizers for resins. When you need to buy a liquid functional ingredient for solubility or moisturizing, PEGs in this range are primary candidates.

As the molecular weight increases into the mid-range, around 1,000 to 4,000 g/mol, PEGs transition from liquids to pastes or waxes. Their viscosity increases, and they retain many of the beneficial properties of lower molecular weight PEGs, while also gaining improved binding and thickening capabilities. These grades are often used as tablet binders in pharmaceuticals, as lubricants in rubber and plastics manufacturing, and as softeners in the paper industry. They represent a versatile middle ground, bridging the gap between liquid solvents and solid binders.

At the higher end, molecular weights of 6,000 g/mol and above, PEGs are typically solids in the form of flakes or powders. These high molecular weight PEGs are characterized by their significantly higher viscosity and their efficacy as binders, lubricants, antistatic agents, and dispersants. In the textile industry, they are used as antistatic agents and softeners. For plastics, they serve as mold release agents and lubricants. They are also employed in the production of detergents, ceramics, and even as components in rocket propellants. When your application demands solid, high-viscosity properties, such as for antistatic treatments or as a binding agent, high molecular weight PEGs are the optimal choice.

For businesses looking to purchase Polyethylene Glycol, understanding how molecular weight dictates function is paramount. Sourcing from a reliable manufacturer, particularly those in China with extensive product lines, ensures access to the precise grade needed for your application. Whether you require a liquid PEG for solvency or a solid PEG for binding and lubrication, clarity on molecular weight will guide you to the most effective and cost-efficient procurement. Consider the performance requirements of your product and then select the PEG molecular weight that best meets those demands.