This site keeps growing as I run into more things worth building. There's no fixed release schedule, so entries land whenever a tool or guide is ready, roughly newest first below. Have a suggestion? Open an issue on GitHub.
๐ Five tools that work on distributions, phases and networks
Every calculator here used to take a few numbers in and give a few numbers back. These five take your actual data, or return a whole curve, and between them they cover the two areas the site had nothing on at all: thermodynamics of mixing and viscoelasticity.
- GPC Trace Analyzer – paste the raw chromatogram and compute Mn, Mw, Mz and Đ yourself, with what the integration limits were worth shown next to the answer. Clipping always narrows a distribution: a sample that is truly Đ = 1.300 reads 1.244 when integrated to 10% of peak height.
- Distribution Simulator – the whole molecular weight distribution a controlled polymerization should give, the dead-chain tail, and what band broadening does to it. Terminating a tenth of the chains drops Mn 8% and barely moves Mw.
- Flory–Huggins Phase Behaviour – binodal, spinodal and critical point for a blend or a solution, the cloud point from χ(T), and the order–disorder transition of a diblock.
- Time–Temperature Superposition – paste isothermal frequency sweeps and get a master curve, shift factors and WLF constants, plus why C₁ and C₂ mean nothing without their reference temperature.
- Network Formation – gel point, sol fraction and elastic strand density for any mix of functionalities, by the Macosko–Miller recursive method.
Each one loads with data generated from a known answer, so the worked example is a measurement of the tool rather than a claim about it, and every published number is re-derived by the site's automated checks on each change.
๐ Chain Dimensions: how big is one chain?
A new tool for the other half of polymer characterisation: not what a chain is made of, but how it is shaped. Pick a polymer and a molar mass and it returns the persistence length, Kuhn length, contour length, end-to-end distance and radius of gyration, using the worm-like chain in its exact form rather than the Gaussian approximation, so it stays correct through the rod-to-coil crossover instead of only in the coil limit. A hundred base pairs of DNA comes back as a rod at 90% of its contour length; three kilobases comes back as a coil with a radius of gyration of 121 nm.
The point of the database is that persistence length is not a material constant. It belongs to a chain in a particular solvent at a particular temperature, and for a charged chain it moves with ionic strength too, so every one of the 25 measurements is quoted with the conditions it was made under and several polymers carry more than one. Single-stranded DNA is 1 nm in high salt and 2.2 nm when the phosphates stop being screened; cellulose reads 6.5 or 9 nm depending on which aggressive solvent dissolved it. Where the values disagree, the disagreement is the data. The 19 entries span from poly(ethylene oxide) at 0.35 nm to an actin filament at 17 ยตm, close to five orders of magnitude.
Where the backbone is a simple aliphatic one the page also predicts lp from the characteristic ratio by geometry alone, and agrees with measurement to within about 15% for polyethylene, polystyrene, PMMA and polypropylene. It refuses to predict for aromatic backbones, because that route genuinely fails there: bisphenol-A polycarbonate has C∞ = 2.4, which the formula turns into 0.22 nm against a measured 1.0. Open Chain Dimensions.
๐ 27 CAS numbers corrected, and you can search by them
Twenty-seven entries in the Polymer Search library listed the CAS number of the monomer where the polymer's number belongs. Poly(caprolactone) carried 502-44-3, which is epsilon-caprolactone, the ring, rather than 24980-41-4, “2-Oxepanone, homopolymer”. It is an easy substitution to make, since the registries index a polymer under the monomer it came from, and a quietly damaging one on a page people copy identifiers out of and paste into a purchase order. All twenty-seven are now the polymer registry number, each checked against EPA's Substance Registry Services or the CAS index name. PCL, PLA, PGA, PCTFE, PECH, poly(butyl acrylate) and poly(alpha-methylstyrene) were among those affected. The data checker now rejects both the specific monomer numbers that were wrong and, more usefully, anything falling outside the ranges CAS actually assigns to polymers, so the error cannot come back the next time the discovery script seeds an entry from monomer data. The name box also searches CAS numbers now, which it never did, so a number off a result card can be pasted straight back in. Open the Polymer Search.
๐งฌ Copolymers in the thermal analysis library
The DSC, TGA and DMA charts now draw from a 70-material library, up from 40, and copolymers have their own category for the first time: 15 of them, including the styrenic thermoplastic elastomers (SBS, SIS), the self-assembling diblocks (PS-b-PMMA, PS-b-P2VP, PS-b-PDMS), the amphiphilic carriers (PEG-b-PLA, Pluronics, PS-b-PEO), and the segmented TPEs (PEBAX, Hytrel). Fifteen homopolymers joined too, filling the obvious gaps: PEO, PCL, PVA, PVAc, PAA, PNIPAM, PVP, PBT, PSU, PPS, PEI and PAN among them. Every entry carries its own provenance and states plainly which numbers are measured and which are estimated, because for block copolymers most of them are composition dependent. A phase separated block copolymer has two glass transitions and the charts draw one, so each entry names the second in its notes rather than pretending it is not there. Open Thermal Analysis.
๐งฑ 29 block copolymers in the reference library
The Polymer Search library went from 2 block copolymers to 29: the styrenic thermoplastic elastomers (SBS, SIS, and SIBS, the TAXUS stent coating), the canonical self-assembly diblocks (PS-b-PMMA of DSA lithography, PS-b-P2VP, PS-b-PDMS), the clinical PEG carriers (PEG-b-PLA of Genexol-PM, the ReGel thermogel triblock), polymersome-forming PB-b-PEO, and the acrylic, silicone, and segmented families (Nanostrength MAM, PEBAX, Hytrel). Nearly all deliberately carry no CAS number: vendor numbers for block copolymers routinely resolve to a homopolymer or a random copolymer of the same monomers, and a wrong identifier is worse than none. The “elastomer” tag is restricted to architectures that actually form a physical network. A diblock with one free chain end does not, however rubbery its soft block. Explore tag chips now also narrow (every selected tag must apply) instead of ORing together. Open the Polymer Search.
๐ Thermal charts scale to fit their data
Every chart on the Thermal Analysis page now fits its axes to the curve instead of assuming a fixed range, so nothing is clipped and a linear polymer’s terminal flow stays on the DMA plot. Marker labels stagger and flip near the edges rather than colliding, and the “binder transitions” view now crops below the first melt as well as the first decomposition, so a binder’s glass transition is actually visible next to a filler that melts before it decomposes.
๐ฅ Thermal Analysis guide: DSC, TGA & DMA
A new interactive guide to the three workhorse thermal techniques, each with a live plot you reshape and read out. Drag a DSC thermogram by heating rate, sample, and first-versus-second heat to watch the glass transition, cold crystallization, melting, and percent crystallinity respond; a TGA/DTG curve by composition and atmosphere to split moisture, polymer, carbon black, and mineral filler; and a DMA plot by frequency and crosslink density to see E′, E″, tan δ, and the three temperatures DMA calls Tg. Open Thermal Analysis.
๐ Sharper publication matching
The publications list on a search result now keeps only papers that actually name the polymer, its monomer, or an alias, instead of everything that shares a family word like “methacrylate.” When a niche polymer has no dedicated literature indexed, it now says so plainly and points you to the PubChem, Scholar, and Patents links rather than filling in with tangential hits. Open the Polymer Search.
๐ฟ Bio-based methacrylates in the reference library
Poly(geranyl methacrylate) and its fully hydrogenated counterpart poly(tetrahydrogeranyl methacrylate), both derived from the plant terpene geraniol, joined the Polymer Search library. They match by name or by drawn structure, and carry a bio-based tag so the renewable-feedstock entries can be browsed together.
๐งฌ Microstructure prediction on the Copolymer Composition tool
The Mayo-Lewis calculator now reads out the likely chain microstructure (alternating, statistical, ideal/random, blocky, or strongly drifting/gradient) from the reactivity-ratio product r₁·r₂, alongside the composition and azeotrope it already computed. The reference table was expanded to 14 common monomer pairs, each value cross-checked against a second source, with the tendency computed live. Open the Copolymer Composition tool.
๐งฉ Copolymer recognition in Polymer Search
Draw a copolymer and bracket each repeat unit separately: the structure search identifies every block with the same exact-match and PubChem machinery a homopolymer uses, then reports the copolymer and pulls publications for the monomer combination. Common named copolymers (SBR/SBS, SAN, ABS, nitrile rubber, PLGA, EVA, EPDM, the Pluronic PEO-PPO surfactants, PS-b-PEG) are in the library too, so they resolve by name and surface automatically when their component blocks are drawn. Open the Polymer Search.
๐ฏ Dispersity (ฤ) Predictor
Predict the narrowest ฤ a controlled radical polymerization can reach from its target DP, conversion, and exchange chemistry. One equation covers RAFT (via the transfer constant Cex), ATRP and NMP (via the deactivator level), and the ideal living limit, with preset RAFT-agent/monomer pairs and ATRP control scenarios drawn from the literature. Shows the molecular-weight distribution as a live SEC trace and how ฤ falls across conversion, with the assumptions the model leaves out stated up front. Open the Dispersity Predictor.
๐งฑ Polyurethane tab in the Calculator
Two-step prepolymer formulation built around capping and chain extension: OH-number-based equivalent weights, NCO:OH capping ratio, theoretical %NCO with a measured-value override for the extension step, extender dosing by index, hard segment content, and a full suggested procedure from polyol drying through cure. Lives alongside ATRP/RAFT/ROMP/FRP in the Calculator, with saved recipes and share links.
๐งด Emulsion Polymerization tab in the Calculator
Micellar (Smith-Ewart) nucleation with SDS and KPS: predicted particle number and diameter from surfactant, initiator, and monomer charge, with a CMC check, solids content, and an advanced option to layer a RAFT or ATRP mediator on top for a controlled/living particle interior. Lives in the Calculator alongside the other techniques.
๐ ๏ธ Site polish: SEO, accessibility, and analytics
Search-friendly meta tags and structured data on every page, a custom 404 page, aria-labels on every icon-only button in the structure editor, a sitemap, and privacy-respecting analytics to see which tools people actually use.
๐ค Automated polymer discovery pipeline
A scheduled job checks a watchlist of common monomers against PubChem, derives the repeat unit structure for the straightforward cases (vinyl, acrylate, methacrylate, diene, and some ring-opening chemistries), and opens a pull request for review. Nothing reaches the live database without a manual check first.
๐ฎ Build a Polymer Chain
A small maze game for practicing skeletal formula conventions: collect the right monomer beads and dodge inhibitors and chain transfer agents before they terminate your chain.
๐ Polymer Search
Look up a common polymer by name, or draw its repeat unit in a freeform structure editor (with ring tools, wedge/hash bonds, and formal charges) and search a curated reference library by structure. Explore mode adds tag browsing and a photo-upload search that reads polymer names or CAS numbers straight off a label or textbook page.
๐ GPC Peak Interpretation, expanded
A troubleshooting quick-reference for common chromatogram artifacts, a multi-detector section, an interactive flow-rate drift calibration demo, and an image-upload trace analyzer for reading Mn/Mw off a real chromatogram photo.
โ๏ธ Recipe Scaling
Scale any polymerization recipe up or down by a factor, or between batch sizes, while keeping every component's ratio exact.
๐ก๏ธ Tg Predictor
Estimate a random copolymer or miscible blend's glass transition temperature from its components using the Fox equation.
๐ GPC Calibration Converter
Convert a polystyrene-equivalent molecular weight from a GPC report into a true molecular weight for the actual polymer, using Mark-Houwink parameters.
๐งฌ Copolymer Composition
Predict instantaneous copolymer composition from feed ratio and reactivity ratios with the Mayo-Lewis equation, including a composition diagram and azeotrope detection.
๐ Glossary, mobile pass, and recipe tools
A glossary of common polymer chemistry terms, a full mobile responsiveness pass, an interactive kinetics plot on the conversion monitoring guide, a print/export stylesheet for recipes, save/reload recipe presets, dispersity (ฤ) guidance on results, and a Stock Solutions tab on the calculator.
๐ Light/dark theme
The calculator and every guide page now follow a light or dark theme, with a toggle in the header.