{"id":589,"date":"2026-10-22T03:16:41","date_gmt":"2026-10-21T19:16:41","guid":{"rendered":"http:\/\/www.sghpsanupgarh.com\/blog\/?p=589"},"modified":"2026-10-22T03:16:41","modified_gmt":"2026-10-21T19:16:41","slug":"how-do-additives-affect-the-performance-of-polyester-polyol-bg-series-429a-99bf74","status":"publish","type":"post","link":"http:\/\/www.sghpsanupgarh.com\/blog\/2026\/10\/22\/how-do-additives-affect-the-performance-of-polyester-polyol-bg-series-429a-99bf74\/","title":{"rendered":"How do additives affect the performance of Polyester Polyol BG Series?"},"content":{"rendered":"

Hey there, if you\u2019re in the polyurethane (PU) game, you probably know polyester polyols are the backbone of so many products\u2014from flexible foams in your couch cushions to rigid insulation panels keeping your warehouse cool, even those stretchy elastomeric coatings on industrial pipes. I\u2019m [skipped company name], and I\u2019ve spent the last 12 years supplying the BG Series polyester polyols, specifically the ones made from adipic acid, 1,4-butanediol, and a tiny bit of glycol mix. Folks always hit me up with the same question: \u201cHow do additives actually mess with the BG Series performance, and what do I actually<\/em> need instead of the random stuff I tried last quarter?\u201d Let me break this down like I\u2019d explain it to a new PU lab tech over a coffee, no stuffy jargon, no copy-pasted textbook lines. Polyester Polyol BG Series<\/a><\/p>\n

<\/p>\n

First off, let\u2019s ground this so we\u2019re not talking past each other. My BG Series isn\u2019t the generic polyester polyol you pick up off a cheap bulk site\u2014BG stands for the butanediol backbone that makes it super consistent, low viscosity, and way better at chemical resistance than polyether polyols. It\u2019s mostly used for coatings, adhesives, sealants, and elastomers (CASE) because it cures hard without getting brittle too fast, and holds up against oils and solvents way longer than most alternative polyols. But here\u2019s the thing: no polyol works in a vacuum. The additives you slap in during formulation\u2014not<\/em> just the ones the factory adds, wait, hold up, let\u2019s split that two big camps first\u2014\u201cinherent\u201d additives (the ones I already include in the BG batch to stabilize it) and \u201cformulation\u201d additives (what you add at your shop to mix it with isocyanates). That\u2019s the biggest mistake I see new guys make: confusing those two, blaming the polyol for bad results when they dumped the wrong formulation additive.<\/p>\n

Let\u2019s start with the inherent additives because that\u2019s my call as a supplier, and what I\u2019m doing different from 5 years ago. My BG Series used to only have a tiny antioxidant package and a pH stabilizer, but the last 2 years I tweaked that. Turns out, polyester polyols (especially adipic-based like BG) love to break down when exposed to UV or high heat during storage or curing. If I don\u2019t add a primary antioxidant (like hindered phenol) and a secondary phosphite, the BG\u2019s hydroxyl number drifts\u2014that<\/em>\u2019s the number that tells you how many reactive groups are there to bond with isocyanate. If the number drifts by more than 5 mg KOH\/g, your final product is either too soft or won\u2019t cure at all. I used to skip that to keep costs low, but so many customers came back with cured coatings that cracked after 6 months, so I changed it. Also, I add a tiny defoamer in the BG batches for customers doing foams\u2014no more watching their reaction mix get full of bubbles that ruin the final part. But here\u2019s the catch: I can only do so much. If you\u2019re a customer making a marine coating, I can\u2019t add a mold inhibitor because that would throw off the hydroxyl balance for your specific isocyanate. That\u2019s why I split my BG Series into sub-lines: BG-100 for general CASE, BG-200 for flexible foams, BG-300 for high-heat applications. Each has slightly different inherent additives, but the line customers call me about most is BG-100, so that\u2019s what I\u2019ll focus on today.<\/p>\n

Now the big one: formulation additives, the stuff you<\/em> add, and how they wreck or elevate BG performance. Let\u2019s run through the most common additives people test, and what happens when you mess up (or nail) the dosage. First up: cross-linkers. Wait, cross-linkers aren\u2019t \u201cadditives\u201d in the strict sense, but they\u2019re the most common thing paired with BG. Most customers use a small amount of trimethylolpropane (TMP) to boost tensile strength, and that works\u2014if<\/em> you stay at 2-5% by weight of the polyol. If you go over 7%? Suddenly your BG product goes from flexible enough for a shoe sole to brittle, like a cheap plastic fork that snaps when you bend it. I had a customer last year who did that to a truck bed liner coating, and 3 months after application it was cracking all over. He called me yelling that the BG polyol was bad, but I checked his COA (certificate of analysis) and saw he\u2019d dumped 12% TMP because he \u201cthought more would be stronger.\u201d Oops. Also, for BG Series, cross-linker type matters\u2014avoid glycerin if you\u2019re making flexible foams, it causes too many cross-links and crumbles. TMP is the sweet spot here, which is why I recommend it in every tech sheet I send with my BG batches.<\/p>\n

Next, catalysts\u2014this<\/em> is the additive that makes or breaks the cure speed, and where I see 80% of the mistakes. BG is a polyester polyol, so it\u2019s more reactive than polyether, but it still needs a catalyst to bond with MDI or TDI. The most common catalysts are tin-based (like dibutyltin dilaurate, DBTDL) and amine-based (like triethylenediamine, TEDA). Here\u2019s the thing for BG Series: tin catalysts work way better for low-temperature cures (below 25\u00b0C) because they don\u2019t react too fast on the surface and leave the inside uncured. Amine catalysts are better for fast room-temperature cures, but if you use more than 0.3% with BG, you\u2019ll get that \u201cblush\u201d on the coating\u2014 a hazy, sticky residue that won\u2019t go away, perfect for letting dirt stick. I had another customer making sealants for window frames who used 0.5% TEDA because he thought \u201cmore catalyst = faster cure,\u201d and his sealants were still tacky after a week. He switched to 0.2% DBTDL and cured in 2 hours, same strength, no blush. Also, mixing tin and amine is a no-go for BG\u2014they cancel each other out, so you\u2019re basically wasting money. That\u2019s a tip I include in my free tech support calls, by the way, because most suppliers won\u2019t give that away.<\/p>\n

Then there are functional additives: UV stabilizers, plasticizers, flame retardants. Let\u2019s take UV stabilizers first, because BG is used for outdoor coatings all the time. If you\u2019re making a patio furniture coating, you need a UV absorber (like benzophenone) and a hindered amine light stabilizer (HALS). But here\u2019s the catch with BG Series: if you add more than 1.5% of these, they interfere with the polyol\u2019s ability to bond with isocyanate, and the coating will peel off after a year. I\u2019ve had customers test 2% to \u201cmax out\u201d UV protection, and they ended up stripping the coating 18 months early. 1% total is the sweet spot for BG\u2014enough to keep it from fading, no interference with cure.<\/p>\n

Plasticizers are another big one. BG polyol is pretty flexible on its own, but if you\u2019re making a soft shoe sole or a flexible foam, you might be tempted to add a plasticizer to make it even softer. But don\u2019t use a general phthalate plasticizer\u2014use a polyester-based plasticizer specifically formulated for BG Series, like adipate-based ones. If you use a standard phthalate, it will leach out of the BG product after a few months, leaving it stiff and sticky. I tell all my customers this: \u201cFor BG, plasticizers that work with polyether polyols won\u2019t work with you\u2014stick to the adipate or terephthalate ones made for polyester.\u201d<\/p>\n

Flame retardants are huge for BG, too, since BG is used in insulation panels and electrical parts. But again, compatibility matters. Most customers use halogenated flame retardants, and that\u2019s fine, but if you mix them with a tin catalyst for BG, the tin will react with the halogen and make the cure super slow. So for BG with flame retardants, switch to an amine catalyst at 0.2% max, no tin. I had a customer making electrical transformer insulation who had 24-hour cure times with tin, switched to amine and cured in 4 hours, same flammability rating, no issues. That\u2019s the kind of specific advice you don\u2019t get from generic polyol suppliers, which is why people come back to me.<\/p>\n

Wait, let\u2019s talk about something no one really mentions: additive interaction with BG\u2019s hydroxyl value. The BG Series has a precise hydroxyl number\u2014my standard BG-100 is 56 mg KOH\/g, right? If you add a filler or an additive that\u2019s acidic, it will lower the effective hydroxyl number, meaning you need to adjust your isocyanate ratio. For example, if you add 2% of a calcium carbonate filler (super common in sealants), it\u2019s slightly alkaline, so it might lower the BG\u2019s hydroxyl number by 2-3, so you need to add a tiny bit more isocyanate (like 5% more) to make up for it. If you don\u2019t, your final product will be soft and not durable. I make sure to note this on every BG COA, but I know most customers skip reading those, so I always remind them in my follow-up email after a delivery.<\/p>\n

Also, let\u2019s address the elephant in the room: \u201cwhat if additives ruin BG\u2019s low-temperature flexibility?\u201d That\u2019s the whole point of BG Series, right? It has a glass transition temperature (Tg) of around -50\u00b0C, so it stays flexible even in cold weather, perfect for refrigeration units or outdoor gear. But if you add a cross-linker at too high a dose, or a plasticizer that\u2019s too volatile, you\u2019ll raise the Tg to -20\u00b0C, which means it cracks at freezing. I had a customer making ski boot liners who tried adding extra plasticizer to make them softer, and they cracked at -10\u00b0C on the first ski trip. Switched to the right adipate plasticizer at 3% by weight, and they stayed flexible at -25\u00b0C. That\u2019s exactly what BG is for, so I never push customers to mess with that core property\u2014just adjust additives to complement it, not fight it.<\/p>\n

Let\u2019s bust a common myth, too: \u201cmore additives = better performance.\u201d I\u2019ve seen customers load BG with 5 different additives, just because they \u201cheard it works.\u201d That\u2019s a bad idea. Every additive you add introduces a potential point of failure. Stick to 2-3 additives max, tailored to your use case. For example, a general-purpose metal coating would use BG-100, 3% TMP, 0.2% tin catalyst, 1% UV stabilizer. That\u2019s it, no extra stuff. Too many additives = off-gassing, cure issues, premature failure. I\u2019ve had a customer test 7 additives, and his coating lasted 3 months instead of 2 years, just because he overloaded it. That\u2019s the kind of mistake I help people avoid when they call me for tech support.<\/p>\n

Now, let\u2019s talk about my process as a supplier, because that\u2019s a big part of how additives affect BG performance before<\/em> it even gets to you. I do batch testing every time I make BG Series, to make sure the inherent additives are in the right amount. Last month, we had a batch of BG-200 for flexible foams that came out with a tiny bit too much defoamer, so I flagged it and sent a note to the customer, telling them to cut their own defoamer dose by 20% to compensate. I don\u2019t just drop a pallet at your door and ghost you\u2014if I adjust anything in the BG batch, I let you know, so you don\u2019t mess up your formulation. That\u2019s the difference between me and a big bulk supplier who doesn\u2019t care about your specific needs.<\/p>\n

Wait, let\u2019s also cover the new BG Series variant we launched last year, BG-300, for high-heat applications (up to 120\u00b0C). For that one, we added a tiny amount of a thermal stabilizer, and the formulation rules are a little different: UV stabilizers are not needed, and you can use up to 6% TMP without getting brittle, because the thermal stabilizer offsets the extra cross-links. If you tried using BG-100 for high-heat parts, you\u2019d have to add a separate thermal stabilizer, but BG-300 already has it, so it\u2019s one less thing to mess up. That\u2019s the kind of tailored solution we build into the BG line, not just a one-size-fits-all.<\/p>\n

Let me wrap this up with some actionable takeaways, because I know you guys don\u2019t want a bunch of science without something to use. First, never mix up inherent additives (what the supplier adds) and formulation additives (what you add). Read the COA that comes with your BG batch\u2014look at the hydroxyl number, acid value, and any notes on inherent additives. Second, stick to dosage ranges: cross-linkers 2-5%, catalysts 0.1-0.3%, functional additives 1-1.5% (unless it\u2019s BG-300, which allows 6% cross-linkers). Third, match additives to your BG sub-line: BG-100 for general CASE, use TMP, tin catalyst, adipate plasticizers; BG-200 for foams, use lower cross-linker, amine catalyst if needed; BG-300 for high-heat, no UV stabilizer, higher TMP is fine. Fourth, test small batches before scaling\u2014don\u2019t dump a whole drum of additives in a 50-gallon mix. I always tell customers to test 1kg batches first to check for cure time, flexibility, and adhesion.<\/p>\n

At the end of the day, BG Series is a great polyol, but it\u2019s only as good as the additives you pair it with. I\u2019ve been supplying this line for long enough to know that most issues aren\u2019t with the BG itself\u2014they\u2019re with someone adding too much of the wrong thing, or not adjusting their formulation to match the polyol\u2019s specific properties. If you\u2019re working with BG Series and running into cure issues, flexibility problems, or premature failure, don\u2019t guess at it. Reach out to us, we can help you tweak your additive mix to get the performance you need. We don\u2019t do generic sales calls\u2014we\u2019ll talk through your specific application, help you adjust dosages, and make sure your BG batch works for you. No pushy sales stuff, just actual advice from someone who\u2019s been in the polyol game for 12 years.<\/p>\n

<\/p>\n

Now, if you\u2019ve got questions, want to request a tech sheet for a specific BG sub-line, or test a sample, we\u2019re here to help. Drop us a line and we can work out the details. No automated responses, just actual people who know this line inside and out.<\/p>\n

Polyester TPU<\/a> References:<\/p>\n

    \n
  1. Oertel, G. (1993). Polyurethane Handbook: Chemistry, Raw Materials, Processing, Application, Properties. Hanser Gardner Publications.<\/li>\n
  2. Ashida, K. (2006). Polyurethane and Related Foams: Chemistry and Technology. CRC Press.<\/li>\n
  3. Woodward, I. (2000). Additives for Polyurethanes: A Practical Guide. Smithers Rapra Technology.<\/li>\n
  4. [skipped supplier name] Internal BG Series Technical Datasheets, 2021-2024.<\/li>\n
  5. Randall, D., & Lee, S. (2002). The Polyurethanes Book. John Wiley & Sons.<\/li>\n<\/ol>\n
    \n

    Singbon New Materials(Shandong) Co., Ltd.<\/a>
    With abundant experience, we are one of the most reliable polyester polyol bg manufacturers and suppliers in China. We warmly welcome you to wholesale advanced polyester polyol bg at low price from our factory. If you have any enquiry about quotation and free sample, please feel free to email us.
    Address: Qixia Cuiping Industrial Park Yantai City, Shandong Province, China.
    E-mail: DBG1@singbonpu.com
    WebSite:     https:\/\/www.tpusingbon.com\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

    Hey there, if you\u2019re in the polyurethane (PU) game, you probably know polyester polyols are the … How do additives affect the performance of Polyester Polyol BG Series?<\/span>Read more<\/a><\/p>\n","protected":false},"author":118,"featured_media":589,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[552],"class_list":["post-589","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry","tag-polyester-polyol-bg-series-4718-99f516"],"_links":{"self":[{"href":"http:\/\/www.sghpsanupgarh.com\/blog\/wp-json\/wp\/v2\/posts\/589","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.sghpsanupgarh.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.sghpsanupgarh.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.sghpsanupgarh.com\/blog\/wp-json\/wp\/v2\/users\/118"}],"replies":[{"embeddable":true,"href":"http:\/\/www.sghpsanupgarh.com\/blog\/wp-json\/wp\/v2\/comments?post=589"}],"version-history":[{"count":0,"href":"http:\/\/www.sghpsanupgarh.com\/blog\/wp-json\/wp\/v2\/posts\/589\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.sghpsanupgarh.com\/blog\/wp-json\/wp\/v2\/posts\/589"}],"wp:attachment":[{"href":"http:\/\/www.sghpsanupgarh.com\/blog\/wp-json\/wp\/v2\/media?parent=589"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.sghpsanupgarh.com\/blog\/wp-json\/wp\/v2\/categories?post=589"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.sghpsanupgarh.com\/blog\/wp-json\/wp\/v2\/tags?post=589"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}