Fengfan CAS 3973-18-0 Propynol Ethoxylate C5H8O2 PME

Product Overview

Propynol ethoxylate, CAS 3973-18-0, is an ethoxylated propargyl alcohol. We supply it as a yellowish to yellow liquid at 98.0% or higher by gas chromatography, and plating shops know it as PME.

In a bright nickel plating bath it is the top brightener. The basic brightener builds the body of the deposit, the leveler smooths the low-current-density areas, and this product finishes the bright end of the range at a working addition of 10–30 ml/L. It is not a stand-alone additive, and it does not replace either of the other two layers.

Two kinds of buyers order it regularly. Plating plants running bright nickel on steel, brass or zinc die castings use it to hold the finish steady from rack to rack. Formulators who build their own brightener blends buy it as a raw intermediate, because a ≥98.0% assay lets them calculate the active content of a formulation instead of guessing what the last drum held.

Handling is straightforward: a liquid at room temperature with a product pH of 3.0–7.0. It is a nickel plating additive for current-driven baths — if you are running a different metal, or a nickel chemistry that deposits without current, look at the rest of the range before you order.

Specifications

Performance in a Bright Nickel Bath

• Finishes the bright work. This is the component that lifts the final lustre of the deposit; it works on top of the basic brightener instead of replacing it.
• Levels fine polishing marks. Acting as a leveling agent, it smooths the shallow scratches and micro-roughness left by mechanical polishing, so less buffing is needed after the plating process.
• Works at the cathode surface. It behaves as a surface active agent in the bath, concentrating where deposition happens rather than staying in the bulk of the solution, which is why a small addition makes a visible difference.
• Dissolves completely. It is well soluble in water, so it spreads through the tank instead of sitting where it was poured in.
• Meters as a liquid. No melting, no dissolving step and no dust at the tank side — it pours and pumps at room temperature.
• Keeps the dose reproducible. Every lot is assayed by GC at ≥98.0%, so a measured volume delivers essentially the same active content drum after drum.

Dosing & Bath Control

1. Confirm you are charging an electrolytic bright nickel bath. This additive is not part of an electroless nickel plating process, which deposits by chemical reduction and needs a different additive set.
2. Start at the low end of the 10–30 ml/L working range and record the figure in the bath log, so the next addition is measured against something.
3. Add at the working addition point with the bath under normal agitation, then let it circulate before the first part goes in.
4. Plate a Hull cell panel and read it across the current density range: burnt or dull at the high-density end usually means the top brightener is short, while haze at the low-density end points at the leveler instead.
5. Raise the addition in small steps inside the range, re-panelling each time, and stop when the finish matches the sample you signed off.
6. Top up in proportion to drag-out and throughput, and plan to re-add after carbon treatment or any purification step, because those strip organic brightener out of the bath.
7. Record the panel result beside the addition figure each time — after a few weeks you have a working curve for your own tank instead of a generic range.

Where It Is Used

• Decorative bright nickel on steel. Tube, sheet and formed parts that are polished, nickel plated and then chromed — the classic job for a top brightener, because the nickel has to be bright enough to show through the chrome.
• Brass and zinc die castings. Sanitary ware, handles and fittings where a smooth nickel layer carries the final lacquer or chrome.
• Automotive and motorcycle hardware. Trim, brackets and fasteners that need a consistent bright finish across a long production run.
• Small parts in barrels. Barrel work runs at a lower current density band with poorer solution exchange, so the addition has to be efficient at a small volume; the 10–30 ml/L range keeps it there.
• Shops running several nickel tanks. One liquid intermediate with a fixed ≥98.0% assay is easier to standardise across lines than a product whose active content you have to work out drum by drum.
• Formulators and metal plating shops. Additive makers blend it into their own top brightener package; plants already buying PPS, PPSOH or ALS from us use it to complete the same system.

Combining With Other Additives

1. Build the basic brightener layer first — a sodium allyl sulphonate type such as our ALS 25% carries the body brightness and ductility of the deposit.
2. Then set the leveler that matches your problem area; PPS, PPSOH or POPS are the usual partners when low-current-density areas come out dull or hazy.
3. Add this top brightener last, at 10–30 ml/L, and panel before anything else goes in.
4. If the defect is pitting rather than brightness, work on the wetting side instead: a non-ionic surface active agent controls foam and pit marks and should be judged separately from the brightener.
5. Do not pre-mix the components in one bucket. Sulphur-bearing brighteners and acetylenic compounds behave differently once diluted, and a combined dose leaves you unable to tell which one moved the panel.
6. When you replace another supplier's top brightener, keep the rest of the plating process unchanged and run the new product through the same panel routine, so the comparison is fair.

Packing & Storage

Each drum is supplied at 25 kg. Keep it closed, upright and in a cool, dry place away from direct sunlight and heat, and use stock in rotation so older drums go first.

Before a drum is charged, check the batch number and assay on the label against your order, then look at the product itself: it should be a yellowish to yellow liquid, uniform from top to bottom. A drum that has turned noticeably darker, or that separates into layers which do not mix back in, should be queried before it goes anywhere near the tank.

In cold weather the liquid can thicken. Let the drum stand at room temperature and roll or stir it before measuring, so the sample you take represents the whole drum. Do not return diluted solution to the original drum — prepare only what you need for the addition. Store and handle it under your local rules for chemical drums, on a bunded area if your site requires one.

Ordering & Delivery

Related Products

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• Electroless nickel processes EN 6786, FF-607 and FI-E300 — for electroless nickel plating lines rather than electrolytic bright nickel, each with its own bath control.

Technical Data & Batch Documents

• Every drum travels with an inspection certificate that quotes the batch number and its warranty period. Ask for that certificate and for the safety data sheet covering your market before the first order, so your own files are complete when the drum lands.
• The data sheet fixes the assay (≥98.0% by GC), the pH (3.0–7.0), the water solubility, the physical form and the 10–30 ml/L addition. It does not fix the bath temperature, the current density band your parts will see, or the consumption per tonne of work — those follow your bright nickel bath, your drag-out and your part geometry.
• Density is not part of the standard specification. If you meter by weight or calibrate a dosing pump in litres, ask us to confirm the figure for the batch you receive instead of assuming 1.00 g/cm³.
• Ductility and internal stress of the deposit are not stated. Where parts are bent, crimped or stitched after nickel plating, plate a trial load and bend-test it before you commit a full drum.
• No chloride or sulphate tolerance and no carry-over figure for drag-out into the next tank is published. Tell us the salt concentration and the tank sequence you run and we will say what we expect, but the working answer comes from a panel on your own line.
• Compatibility is described by layer rather than by brand: this is a top brightener sitting above a basic brightener and a leveler. If you need to know whether it fits a specific commercial package, send the package name, and compare Hull cell panels made with and without the change.
• Storage beyond "cool and dry" is not pinned to a number, so a drum that will stand for months should be checked before charging: yellowish to yellow, uniform from top to bottom, with no layer that will not stir back in. Query the drum before it goes near the tank.
• No REACH, RoHS or similar statement is issued with this product. Tell us the destination market and the declaration your customer is asking for, and we will confirm what the supplying plant can provide; we will not put a compliance claim on paper that has not been issued to us.

Technical Support & Model Matching

Choosing the right match is where most sourcing decisions stall. As a trading supplier, we keep one point of contact from first enquiry to after-sales: tell us what you are making and the conditions you work under, and we shortlist the closest matches from our supplier network, compare specifications and arrange samples before you commit to a bulk order. If something does not behave as expected, we work with the supplying partner on the cause and a practical fix, and stay with the case until it is settled. Email, WeChat or WhatsApp enquiries get a reply within 24 hours.

FAQ