Why are acid value and moisture critical when selecting DMT for PBT production?

While purity (≥99.95%) is the baseline, acid value (≤0.05 mg KOH/g) and moisture (≤0.02%) govern reaction kinetics. Acid value deactivates titanium ester exchange catalysts, while moisture triggers hydrolysis, reducing molecular weight and sharply increasing THF byproduct formation.

What are the operational advantages of using DMT over PTA in PBT synthesis?

The DMT route via transesterification with 1,4-butanediol (BDO) generates recoverable high-purity methanol, minimizes THF byproduct formation (reducing BDO consumption), and delivers narrower molecular weight distribution with superior color stability.

How does Demeto ensure batch-to-batch consistency for polyester-grade DMT?

Demeto implements a closed-loop qualification system: technical protocol benchmarking, representative lab samples, pilot lot validation, and lot retention. Every commercial batch is accompanied by an authentic COA with verified GC-FID purity, Karl Fischer moisture, and potentiometric acid value.

PBT APPLICATION

Dimethyl terephthalate (DMT) for PBT production

PBT performance depends on more than headline purity. Moisture, acid value, color and trace impurities influence process stability and final resin quality.

OVERVIEW

Qualification priorities

Translate polymerization risks into measurable feedstock controls.

MOISTURE

Protect reaction stability

Control moisture to reduce variability in transesterification and downstream polymerization.

ACID VALUE

Monitor hydrolysis-related risk

Use acid value with moisture and storage history, rather than as an isolated metric.

IMPURITIES

Protect color and performance

Evaluate ash, metals and organic trace impurities against resin requirements.

CONSISTENCY

Validate across batches

Compare representative samples and shipment COA data before recurring supply.

REFERENCE

Key product information

Recommended starting grade: Polyester Grade DMT
Key controls: Moisture, acid value, color, ash and trace impurities
Validation: Lab or pilot polymerization trial
Supply progression: Sample to pilot lot to recurring contract

PROJECT CHECKLIST

What to confirm

Define target resin and process routeReview a representative COAComplete sample or pilot validationLock specification and batch release process

PROCUREMENT

What PBT buyers should ask before ordering DMT

PBT lines run continuously, so consistency and delivery matter as much as the headline assay.

Question to ask	Underlying risk	Recommended action
How stable is the DMT purity?	Variation in the main assay can disturb polymerization	Request COA for recent batches and run a laboratory sample first
Are acid value and moisture controlled?	They affect reaction stability and the process window	State the target range and test method in your RFQ
Is there a batch consistency record?	A good sample followed by variable bulk creates production risk	Ask for lot numbers, COA and a batch reservation mechanism
Can delivery be sustained?	PBT production is continuous, so a supply gap is costly	Confirm available source, lead time and a monthly or quarterly supply plan in writing
Is price the only criterion?	The lowest price may sacrifice delivery and consistency	Weigh specification, documents, lead time and ongoing service together

RELATED ACTIONS

Continue the qualification

NEXT STEPQuote factorsPrepare grade, package, volume and destination before requesting a current quote.NEXT STEPSamples & small packsReview the trial purpose, batch documents and availability before planning a test.NEXT STEPDownloadable toolsUse the procurement workbook, buyer guide and document-review checklist.NEXT STEPSubmit a structured RFQShare the application, critical limits, volume, packaging, destination and required documents.

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Turn your requirements into a reviewable supply plan

Share your application, target specification, volume and destination — we’ll confirm the next practical step and the available COA or sample basis.

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