The influence of initiator Diol-BF3 complex solubility and other factors on the induction period in BF3 catalyzed cationic ring opening polymerization of epichlorohydrin

Kim, Jeong Su; Kim, Du Ki; Kweon, Jeong-Ohk; Lee, Jae-Myung; Noh, Si Tae; Kim, Sun Young

doi:10.1007/s13233-014-2056-3

Cited by 6 publications

(18 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The effect was described by Kim et al and is linked to the aggregation of BDO with boron trifluoride at the start of the monomer addition [14,18]. Aggregated initiators are thought to be less reactive [18,19] and can cause an uncontrolled favoring of the ACE mechanism to result in the formation of cyclic oligomers, a high polydispersity, and decreased hydroxyl group functionality [14]. The fact that a considerably increased addition time only resulted in a slight improvement (Table 2) is consistent with the assumption of an induction period due to a reduced initiator activity.…”

Section: Gel Permeation Chromatographymentioning

confidence: 99%

Energetic Polymers: A Chance for Lightweight Reactive Structure Materials?

Born

Plank

Klapötke

2022

Propellants Explo Pyrotec

View full text Add to dashboard Cite

Today's ammunition still consists of about 70 wt% structure‐providing materials such as metals providing no energetic contribution. Therefore, reactive structure materials (RSMs) offer tremendous room for improvement. While current research focuses on rather heavy, metal‐based materials (e. g., alloys, thermites), energetic polymers appear as an under‐recognized opportunity for very lightweight RSMs. Unfortunately, suitable polymers are unavailable as energetic polymer research has almost exclusively focused on elastic binders with the least possible glass transition temperature. An application as RSM, however, requires rigid polymers with a glass transition above operational temperatures. Accordingly, monomers with fundamentally different structures are required. The first step in this particular direction is 3‐(2,4,6‐trinitrophenoxy)oxetane (TNPO). Herein, we report the synthesis of its homopolymer and investigate its polymerization behavior by copolymerization with prior art energetic oxetanes. All polymers were intensively studied by vibrational and multinuclear (1H, 13C, 14N) NMR spectroscopy, elemental analysis, gel permeation chromatography, and differential scanning calorimetry (DSC). Hereby, DSC revealed the high effect of the TNPO repeating unit on the glass transition temperature. The performance of all polymers was calculated using the EXPLO5 code to evaluate the potential performance range of polymeric RSMs. Further, their shock and friction sensitivity was determined by BAM standard procedures.

show abstract

Section: Gel Permeation Chromatographymentioning

confidence: 99%

Energetic Polymers: A Chance for Lightweight Reactive Structure Materials?

Born

Plank

Klapötke

2022

Propellants Explo Pyrotec

View full text Add to dashboard Cite

show abstract

“…Kim et al explained the induction phenomenon by the aggregation of 1,4-butanediol with the catalyst BF 3 xTHF at the beginning of the monomer addition. Aggregated initiators are supposed to be less reactive than non-aggregated [33,34]. This induction period should be avoided or at least as short as possible, since accumulated unreacted monomers could lead to the formation of cyclic oligomers by favoring ACE propagation and therefore to a higher polydispersity of the final product.…”

Section: Synthesis and Characterization Of Copolymersmentioning

confidence: 99%

Copolymers based on GAP and 1,2‐Epoxyhexane as Promising Prepolymers for Energetic Binder Systems

Hafner

Keicher

Klapötke

2017

Propellants Explo Pyrotec

View full text Add to dashboard Cite

Copolymers of epichlorohydrin (ECH) and 1,2‐epoxyhexane (EpH) have been synthesized via cationic ring‐opening polymerization using BF3×THF as a catalyst. Structures of the resulting polymers have been confirmed by IR and NMR spectroscopy and GPC. In a subsequent reaction with NaN3 in DMSO, the halogenated precursors were completely azidated, which was confirmed by the same spectroscopic methods. The introduced pendant n‐butyl chains act as an internal plasticizer by lowering the glass transition temperature (Tg) of the copolymers compared to the reference compound glycidyl azide polymer (GAP). Compared to GAP in a similar molecular weight range, the copolymers also showed reduced viscosity. These properties make the described copolymers interesting candidates for use as energetic binders in cast‐cure applications.

show abstract

“…1,4-cyclohexanediol, and even polyethylene glycols ( M n = 200–600 g mol –1 ) were used as initiators of cationic ROP of ECH in conjunction with BF 3 •Et 2 O, mainly at 0 °C. However, PECH s obtained with these different initiators are often characterized by relatively high dispersity (Đ = 1.40–2.15) and a functionality lower than 2.0; moreover, their SEC traces display shoulder or even a separate peak in the low molar mass region, indicating the formation of cyclic by-products. − The main differences between these works and Penczek’s one lie in the nature of the initiator, the polymerization temperature, and the initiator to co-initiator ratio ([EG]/[BF 3 •Et 2 O] ≈ 50).…”

Section: Introductionmentioning

confidence: 99%

“…The cationic ROP of ECH was already largely described in the literature, using catalytic systems based on Lewis acids such as BF 3 •Et 2 O, − SnCl 4 , Et 3 O + PF 6 – , and…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Chlorinated Solvent-Free Living Cationic Ring-Opening Polymerization of Epichlorohydrin Using BF₃•OEt₂ as Co-Initiator: Toward Perfectly Functionalized Poly(epichlorohydrin) Diols

Timofeev,

Hulnik,

Vasilenko

et al. 2023

ACS Appl. Polym. Mater.

View full text Add to dashboard Cite

The cationic ring-opening polymerization of epichlorohydrin co-initiated by BF 3 •Et 2 O has been investigated here. Fast synthesis of pure poly(epichlorohydrin) diols (F n (OH) ≈ 2.0) with controlled molar mass (M n up to 4000 g mol −1 ) and low dispersity (Đ < 1.25) was performed both in toluene and in bulk. An original approach was developed here, consisting of first generating in situ the initiator through the BF 3 •Et 2 O-catalyzed reaction of ECH with water, leading to a mixture of oligomers with better solubility in the reaction medium than conventional initiators previously used. Then, through a second monomer starved-feed step, polymerization proceeds exclusively through the activated monomer mechanism, allowing perfect control of the polymer growth. The developed procedure was successfully upscaled to 100 g of polymer to validate a future industrial production of PECH, as well as its derivative glycidyl azide polymer (GAP), the most important energetic binder for solid propellants. Additionally, a separate study was performed to elucidate the reasons for coloration of the polymer observed in the course of polymerization and/or under storage.

show abstract

The influence of initiator Diol-BF3 complex solubility and other factors on the induction period in BF3 catalyzed cationic ring opening polymerization of epichlorohydrin

Cited by 6 publications

References 24 publications

Energetic Polymers: A Chance for Lightweight Reactive Structure Materials?

Energetic Polymers: A Chance for Lightweight Reactive Structure Materials?

Copolymers based on GAP and 1,2‐Epoxyhexane as Promising Prepolymers for Energetic Binder Systems

Chlorinated Solvent-Free Living Cationic Ring-Opening Polymerization of Epichlorohydrin Using BF₃•OEt₂ as Co-Initiator: Toward Perfectly Functionalized Poly(epichlorohydrin) Diols

Contact Info

Product

Resources

About

The influence of initiator Diol-BF3 complex solubility and other factors on the induction period in BF3 catalyzed cationic ring opening polymerization of epichlorohydrin

Cited by 6 publications

References 24 publications

Energetic Polymers: A Chance for Lightweight Reactive Structure Materials?

Energetic Polymers: A Chance for Lightweight Reactive Structure Materials?

Copolymers based on GAP and 1,2‐Epoxyhexane as Promising Prepolymers for Energetic Binder Systems

Chlorinated Solvent-Free Living Cationic Ring-Opening Polymerization of Epichlorohydrin Using BF3•OEt2 as Co-Initiator: Toward Perfectly Functionalized Poly(epichlorohydrin) Diols

Contact Info

Product

Resources

About

Chlorinated Solvent-Free Living Cationic Ring-Opening Polymerization of Epichlorohydrin Using BF₃•OEt₂ as Co-Initiator: Toward Perfectly Functionalized Poly(epichlorohydrin) Diols