Poly(α-methyl-β-propiolactone) Hot Melt Adhesive Stereochemistry

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current bio-based and degradable polymers lack the properties to replace petroleum-based styrene block copolymers and polyolefins used in hot melt adhesive and pressure-sensitive adhesive products, failing to provide low modulus, elastomeric adhesives with high bonding performance.

Innovation Solution

A composition comprising poly(α-methyl-β-propiolactone) or its derivatives, polymerized from (R)- and (S)-α-methyl-β-propiolactone monomers in specific ratios, forming triblock copolymers with distinct blocks to achieve desired thermomechanical properties, including silane-modified, moisture-curable, or polyurethane derivatives, which are applied as hot melt adhesives.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If bio-based and degradable polymers are used to replace petroleum-based styrene block copolymers and polyolefins in hot melt adhesive formulations, then environmental sustainability is improved, but adhesive performance and material properties are worsened

Engineering Contradiction:

Improveenvironmental sustainabilityVSAvoidadhesive performance

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the stereochemical parameters of the polymer by controlling the ratio of (R)- and (S)-α-methyl-β-propiolactone monomers during polymerization. By adjusting the enantiomeric composition, the patent achieves phase-separated morphology and desired hard-soft behavior in the adhesive, thereby maintaining reliable adhesive performance while using bio-based polymers

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system by incorporating poly(α-methyl-β-propiolactone) with specific stereochemistry into hot melt adhesive formulations. The phase-separated morphology created by the stereoregular polymer structure provides both the mechanical properties and adhesive performance needed to replace petroleum-based materials

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If poly(α-methyl-β-propiolactone) is polymerized from racemic or near-racemic monomer mixtures, then manufacturing simplicity is improved, but thermomechanical properties and adhesive performance are worsened

Engineering Contradiction:

Improvemanufacturing simplicityVSAvoidthermomechanical properties

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by controlling the enantiomeric composition parameter during polymerization. By specifying that the polymer be made from monomers with specific (R):(S) ratios (including racemic and near-racemic mixtures), the patent achieves the desired phase-separated morphology and thermomechanical properties without requiring complex manufacturing processes

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution provides biobased, compostable adhesives with low modulus, elastomeric properties, suitable for various applications, including laminates and packaging, offering thermal resistance and quick bonding without solvent carriers.

Implementation Method 1

the poly(α-methyl-β-propiolactone) is polymerized from a plurality of (R)-α-methyl-β-propiolactone monomers and a plurality of (S)-α-methyl-β-propiolactone monomers

Methodology Applied

Scientific EffectRing-opening polymerization:

Implementation Method 2

applying a hot melt adhesive composition as described herein a molten state to a primary substrate; mating a secondary substrate to the primary substrate by contacting the secondary substrate with the composition; and solidifying the composition by cooling the composition

Methodology Applied

Scientific EffectMelting and solidification: Melting

Data Source

PatentUS20250109291A1Hot melt adhesive compositions based on poly (alpha-methyl-beta-propiolactone) polymers or derivatives and methods for using them

Publication Date: 2025.04.03 BOSTIK SA(FR)

AI summary

A hot melt adhesive composition comprises a polymer comprising poly(α-methyl-β-propiolactone) (PMPL) or a derivative thereof, wherein the PMPL is polymerized from a plurality of (R)-α-methyl-β-propiolactone monomers and a plurality of (S)-α-methyl-β-propiolactone monomers, wherein the ratio of (R):(S) monomers is from about 90:10 to about 10:90. Changing the (R):(S) ratio impacts the isotactic diad fraction and consequently the crystallinity and thermomechanical properties of the resulting PMPL. The PMPL may be hydroxyl-terminated, with the residue thereof serving as the elastomeric B block in an A:B:A triblock copolymer having hard end A blocks, such as a residue of polylactic acid. The PMPL diol may also be used as a reactant to form an alkoxysilane-terminated polymer, a polyurethane, or a (co)polyester. In some embodiments, such triblock polymers may be entirely bio-sourced and compostable.