How this works
Search a curated reference library of common polymers by name, or draw a repeat unit below and search by structure.
How structure search works, and its limits
Draw a little more than one repeat unit, the way you'd sketch a few units of a chain in a paper: a stub of the neighboring unit on each side, then your actual repeat unit in the middle, then drag the bracket tool over just the middle part. The bracket tool needs a real bond crossing each edge to know where the chain keeps going, so it won't work if the whole drawing is inside the bracket. Try the load example buttons below to see the pattern before drawing your own.
Matching is graph based: your drawing is compared by its atoms and bonds, not by how it is laid out on the canvas, so the same repeat unit drawn at a different angle or size still matches. When nothing in the library is identical, the search falls back to ranking the closest structures by chemical similarity (Morgan fingerprints, the same idea behind similarity search in the big chemistry databases) with a percentage on each suggestion. The matching engine (RDKit, about 7 MB) loads the first time you run a structure search and stays cached after that.
This is a small, hand curated reference set, not an exhaustive registry like SciFinder or PubChem: it currently covers common addition, step growth, and ring opening homopolymers. Branched and crosslinked repeat units, and copolymers, aren't matched yet. Tg and Tm values shown are typical literature figures for reference only.
Search by name
Search by structure
Tips & keyboard shortcuts
Draw
- Bond
- Click empty space to place an atom, then click any atom to add a bond off it at the correct angle automatically — no aiming needed. Click a bond to cycle single/double/triple.
- Drag from an atom
- For a custom angle, or drop onto another atom to connect them directly (e.g. to close a ring).
- Wedge / Hash
- Same chain-building, drawn as stereo bonds. Cosmetic only — not used for structure search.
- Chain
- Click and drag to lay down several atoms at once.
Edit
- Select
- Drag a box to select atoms, then drag a selected atom to move the whole group.
- Rotate
- Drag to spin the current selection around its center.
- Relabel
- Pick an element, then click an atom to change it.
- Erase
- Click an atom or bond to remove it.
- Bracket
- Drag a box around the repeat unit.
Rings & charge
- Ring size / Benzene
- Click an atom to spiro-fuse the ring there, click a bond to edge-fuse it (e.g. naphthalene), or click empty space for a free-standing ring.
- Scroll while placing a ring
- Rotates the preview (or flips it to the other side of a bond) before you click to commit it.
- Charge +/−
- Click an atom to add positive or negative formal charge.
Shortcuts
- Escape
- Release the current chain without adding another atom.
- Hover + letter key
- Relabel the hovered atom instantly, in any mode. N, O, F apply right away; C, S, B briefly wait in case a second letter completes Cl, Si, or Br.
- Shift+click
- Relabel an atom to the selected element without adding a bond.
- Molecular weight
- The bar under the canvas shows the formula, molar mass, exact mass, degree of unsaturation, and elemental analysis of whatever you draw, implicit hydrogens included. Highlight atoms with the Select tool to weigh just that fragment.
- SMILES
- Paste a SMILES below the canvas and Load draws it with clean geometry. Copy SMILES / Copy InChI turn your drawing into a string ready for PubChem, SciFinder, or a manuscript.
- Clean up
- The ✨ button redraws your sketch with ideal bond lengths and angles, keeping atoms, bonds, and charges exactly as you placed them.
- Grid icon
- Pick any element from the periodic table.
Explore
Browse the library by tag, or upload a photo of a label, textbook page, or datasheet - any printed polymer name or CAS number in the image gets matched automatically.
Results
Can't find a polymer that should be here? Suggest it on GitHub and it'll be considered for the reference library.