Polymers

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14 pages, 5087 KiB

Open AccessArticle

Photochromic Polyamide 6 Based on Spiropyran Synthesized via Hydrolyzed Ring-Opening Polymerization

by Shiyou Tian, Jicong Zhang, Qiong Zhou, Limei Shi, Wenwen Wang and Dong Wang

Polymers 2021, 13(15), 2496; https://doi.org/10.3390/polym13152496 - 28 Jul 2021

Cited by 3 | Viewed by 2702

We report photochromic polyamide 6 (PA6) which was synthesized by hydrolyzed ring-opening polymerization of ε-caprolactam with spiropyran (SP) embedded in the polymer chains. It indicated that crystallinity degree of the resulting copolymers was decreased since only PA6 segments can crystallize with increasing content [...] Read more.

We report photochromic polyamide 6 (PA6) which was synthesized by hydrolyzed ring-opening polymerization of ε-caprolactam with spiropyran (SP) embedded in the polymer chains. It indicated that crystallinity degree of the resulting copolymers was decreased since only PA6 segments can crystallize with increasing content of SP modifier. Meanwhile, toughness of photochromic PA6 was decreased. The photochromic property analysis indicated that the sample with more flexibility and more content of SP was more sensitive to UV light at the beginning of irradiation than other samples and its color after being irradiated for 1 min tended to reddish. Investigation revealed that the UV-vis absorbance of SP-PA6-3 had negligible decay after 10 cycles, which indicated SP-modified PA6 possessed excellent photoresponse reversibility and fatigue resistance. Full article

(This article belongs to the Special Issue Ring Opening Polymerization: A Synthetic Toolbox for New Monomers and Polymers with Tailor-Made Properties and Functions)

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18 pages, 2306 KiB

Open AccessArticle

Copolymerization of Phthalic Anhydride with Epoxides Catalyzed by Amine-Bis(Phenolate) Chromium(III) Complexes

by Wiktor Bukowski, Agnieszka Bukowska, Aleksandra Sobota, Maciej Pytel and Karol Bester

Polymers 2021, 13(11), 1785; https://doi.org/10.3390/polym13111785 - 28 May 2021

Cited by 5 | Viewed by 3833

Abstract

The effect of ligand structure on the catalytic activity of amine-bis(phenolate) chromium(III) complexes in the ring-opening copolymerization of phthalic anhydride and a series epoxides was studied. Eight complexes differing in the donor-pendant group (R₁) and substituents (R₂) in phenolate [...] Read more.

The effect of ligand structure on the catalytic activity of amine-bis(phenolate) chromium(III) complexes in the ring-opening copolymerization of phthalic anhydride and a series epoxides was studied. Eight complexes differing in the donor-pendant group (R₁) and substituents (R₂) in phenolate units were examined as catalysts of the model reaction between phthalic anhydride and cyclohexane oxide in toluene. They were used individually or as a part of the binary catalytic systems with nucleophilic co-catalysts. The co-catalyst was selected from the following organic bases: PPh₃, DMAP, 1-butylimidazole, or DBU. The binary catalytic systems turned out to be more active than the complexes used individually, and DMAP proved to be the best choice as a co-catalyst. When the molar ratio of [PA]:[epoxide]:[Cr]:[DMAP] = 250:250:1:1 was applied, the most active complex (R₁-X = CH₂NMe₂, R₂ = F) allowed to copolymerize phthalic anhydride with differently substituted epoxides (cyclohexene oxide, 4-vinylcyclohexene oxide, styrene oxide, phenyl glycidyl ether, propylene oxide, butylene oxide, and epichlorohydrin) within 240 min at 110 °C. The resulting polyesters were characterized by M_n up to 20.6 kg mol⁻¹ and narrow dispersity, and they did not contain polyether units. Full article

(This article belongs to the Special Issue Ring Opening Polymerization: A Synthetic Toolbox for New Monomers and Polymers with Tailor-Made Properties and Functions)

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13 pages, 4503 KiB

Open AccessArticle

Synthesis of Poly(Trimethylene Carbonate) from Amine Group Initiation: Role of Urethane Bonds in the Crystallinity

by Thomas Brossier, Gael Volpi, Vincent Lapinte and Sebastien Blanquer

Polymers 2021, 13(2), 280; https://doi.org/10.3390/polym13020280 - 16 Jan 2021

Cited by 6 | Viewed by 3678

Abstract

Semi-crystalline poly(trimethylene carbonate) (PTMC) can be efficiently prepared by ring-opening polymerization (ROP) initiated by amine using various catalysts. More promising results were reached with the one-step process of stannous octanoate unlike the two-step one-pot reaction using TBD and MSA catalysts. The ROP-amine of [...] Read more.

Semi-crystalline poly(trimethylene carbonate) (PTMC) can be efficiently prepared by ring-opening polymerization (ROP) initiated by amine using various catalysts. More promising results were reached with the one-step process of stannous octanoate unlike the two-step one-pot reaction using TBD and MSA catalysts. The ROP-amine of TMC consists in a simple isocyanate free process to produce polycarbonate-urethanes, compatible with the large availability of amines ranging from mono- to multifunctional until natural amino acids. ROP-amine of TMC leads to urethane bonds monitored by FTIR spectroscopy. The relationship between the nature of amines and the crystallinity of PTMC was discussed through X-ray diffraction and thermal studies by DSC and TGA. The impact of the crystallinity was also demonstrated on the mechanical properties of semi-crystalline PTMC in comparison to amorphous PTMC, synthesized by ROP initiated by alcohol. The semi-crystalline PTMC synthesized by ROP-amine opens many perspectives. Full article

(This article belongs to the Special Issue Ring Opening Polymerization: A Synthetic Toolbox for New Monomers and Polymers with Tailor-Made Properties and Functions)

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10 pages, 2113 KiB

Open AccessArticle

Chiral 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD)-Catalyzed Stereoselective Ring-Opening Polymerization of rac-Lactide: High Reactivity for Isotactic Enriched Polylactides (PLAs)

by Qaiser Mahmood, Guangqiang Xu, Li Zhou, Xuanhua Guo and Qinggang Wang

Polymers 2020, 12(10), 2365; https://doi.org/10.3390/polym12102365 - 15 Oct 2020

Cited by 5 | Viewed by 3072

Abstract

Chiral 4,8-diphenyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (DiPh-TBD) was synthesized and applied to a ring-opening polymerization of rac-lactide (rac-LA). The chiral DiPh-TBD promoted the synthesis of isotactic enriched polylactides (PLAs) with controlled molecular weight and narrow molecular weight distributions under mild, metal-free conditions. When the [...] Read more.

Chiral 4,8-diphenyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (DiPh-TBD) was synthesized and applied to a ring-opening polymerization of rac-lactide (rac-LA). The chiral DiPh-TBD promoted the synthesis of isotactic enriched polylactides (PLAs) with controlled molecular weight and narrow molecular weight distributions under mild, metal-free conditions. When the [rac-LA]/[Cat.] ratio was 100/1, full monomer conversion was achieved within only 1 min and a moderate probability of 0.67 meso dyads (P_m) was obtained at room temperature. A chain-end control mechanism (CEC) was found to be responsible for the isoselectivity based on the homodecoupled ¹H NMR spectrum, the chiral HPLC measurement, and kinetic studies. Full article

(This article belongs to the Special Issue Ring Opening Polymerization: A Synthetic Toolbox for New Monomers and Polymers with Tailor-Made Properties and Functions)

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17 pages, 3952 KiB

Open AccessArticle

Lastingly Colored Polylactide Synthesized by Dye-Initiated Polymerization

by Dawid Jędrzkiewicz, Sebastian Kowalczyk, Andrzej Plichta and Jolanta Ejfler

Polymers 2020, 12(9), 1980; https://doi.org/10.3390/polym12091980 - 31 Aug 2020

Cited by 1 | Viewed by 2709

Abstract

An efficient synthesis strategy of a well-defined polylactide–dye conjugate in a controlled fashion is presented. The introduction of coloring species as end groups of polylactide (PLA) has been performed by using new homoleptic aminophenolate magnesium or zinc coordination compounds. The molecular structure of [...] Read more.

An efficient synthesis strategy of a well-defined polylactide–dye conjugate in a controlled fashion is presented. The introduction of coloring species as end groups of polylactide (PLA) has been performed by using new homoleptic aminophenolate magnesium or zinc coordination compounds. The molecular structure of metal complexes has been determined in solution by NMR spectroscopy, and in the solid state by X-ray analysis. Lastingly colored polymers were obtained with 2-[4-(Nitrophenylazo)-N-ethylphenylamino]ethanol (Disperse Red 1) and 2-[4-(2-Chloro-4-nitrophenylazo)-N-ethylphenylamino]ethanol (Disperse Red 13) at very high lactide conversions, based on MALDI-ToF measurement, and the macromolecules were nearly fully chain end dye-functionalized. Based on ¹H NMR, the DP_n of conjugates was in the range of 10–300, which was consistent with the reaction setup. Various methods of gel-permeation chromatography (GPC) analysis were applied, and they demonstrated that the number-average molar mass (M_n) values (polystyrene (PS) standards) were a bit higher than calculated, the molar mass distribution index (Ɖ_M) values were moderate to high, the TDA (triple detection array) system was inappropriate for analysis, measurements with PDA (photo diode array) detection at 470 nm gave nearly the same molar mass distributions such as the refractometer, and the relative absorbance of conjugates at 470 nm increased linearly versus (DP_n)⁻¹. The presented approach connects the gap between the current strategy of obtaining colored polymer fibers and the design of tailor-made initiators with eco polyesters designed for the targeted applications. Full article

(This article belongs to the Special Issue Ring Opening Polymerization: A Synthetic Toolbox for New Monomers and Polymers with Tailor-Made Properties and Functions)

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8 pages, 3272 KiB

Open AccessCommunication

Post-Polymerization Modification of Ring Opening Metathesis Polymerization (ROMP)-Derived Materials Using Wittig Reactions

by Ryan Duty and Christopher E. Hobbs

Polymers 2020, 12(6), 1247; https://doi.org/10.3390/polym12061247 - 29 May 2020

Cited by 1 | Viewed by 3666

Abstract

This communication describes our recent efforts to utilize Wittig olefination reactions for the post-polymerization modification of polynorbornene derivatives prepared through ring opening metathesis polymerization (ROMP). Polymerizing α-bromo ester-containing norbornenes provides polymers that can undergo facile substitution with triphenylphosphine. The resulting polymeric phosphonium salt [...] Read more.

This communication describes our recent efforts to utilize Wittig olefination reactions for the post-polymerization modification of polynorbornene derivatives prepared through ring opening metathesis polymerization (ROMP). Polymerizing α-bromo ester-containing norbornenes provides polymers that can undergo facile substitution with triphenylphosphine. The resulting polymeric phosphonium salt is then deprotonated to form an ylide that undergoes reaction with various aryl aldehydes in a one-pot fashion to yield the respective cinnamates. These materials can undergo further modification through photo-induced [2 + 2] cycloaddition cross-linking reactions. Full article

(This article belongs to the Special Issue Ring Opening Polymerization: A Synthetic Toolbox for New Monomers and Polymers with Tailor-Made Properties and Functions)

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18 pages, 4196 KiB

Open AccessArticle

Copolymacrolactones Grafted with l-Glutamic Acid: Synthesis, Structure, and Nanocarrier Properties

by Ernesto Tinajero-Díaz, Antxon Martínez de Ilarduya and Sebastián Muñoz-Guerra

Polymers 2020, 12(4), 995; https://doi.org/10.3390/polym12040995 - 24 Apr 2020

Cited by 7 | Viewed by 3977

Abstract

The enzymatic ring-opening copolymerization (eROP) of globalide (Gl) and pentadecalactone (PDL) was performed in solution from mixtures of the two macrolactones at ratios covering the whole range of comonomeric compositions. The resulting P(Gl_x-r-PDL_y) random copolyesters were aminofunctionalized [...] Read more.

The enzymatic ring-opening copolymerization (eROP) of globalide (Gl) and pentadecalactone (PDL) was performed in solution from mixtures of the two macrolactones at ratios covering the whole range of comonomeric compositions. The resulting P(Gl_x-r-PDL_y) random copolyesters were aminofunctionalized by thiol-ene reaction with aminoethanethiol. ROP of γ-benzyl-l-glutamate N-carboxyanhydride initiated by P(Gl_x-r-PDL_y)-NH₂ provided neutral poly(γ-benzyl-l-glutamate)-grafted copolyesters, which were converted by hydrolysis into negatively charged hybrid copolymers. Both water-soluble and nonsoluble copolymers were produced depending on copolymer charge and their grafting degree, and their capacity for self-assembling in nano-objects were comparatively examined. The emulsion solvent-evaporation technique applied to the chloroform-soluble copolymers grafted with benzyl glutamate rendered well-delineated spherical nanoparticles with an average diameter of 200–300 nm. Conversely, micellar solutions in water were produced from copolyesters bearing grafted chains composed of at least 10 units of glutamic acid in the free form. The copolymer micelles were shown to be able to load doxorubicin (DOX) efficiently through electrostatic interactions and also to release the drug at a rate that was markedly pH dependent. Full article

(This article belongs to the Special Issue Ring Opening Polymerization: A Synthetic Toolbox for New Monomers and Polymers with Tailor-Made Properties and Functions)

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13 pages, 14564 KiB

Open AccessArticle

Developing Further Versatility in Benzoxazine Synthesis via Hydrolytic Ring-Opening

by Shaoying Cui, Carlos R. Arza, Pablo Froimowicz and Hatsuo Ishida

Polymers 2020, 12(3), 694; https://doi.org/10.3390/polym12030694 - 20 Mar 2020

Cited by 9 | Viewed by 3568

Abstract

In this study, 2-(aminomethyl)phenol and its derivatives, the reactants for 2-substituted 1,3-benzoxazines, are synthesized by HCl hydrolysis from the typical benzoxazines. The phenol/aniline-based mono-oxazine benzoxazine, PH-a, and the bisphenol A/aniline-based bis-oxazine benzoxazine, BA-a, are used as examples to demonstrate the feasibility of this [...] Read more.

In this study, 2-(aminomethyl)phenol and its derivatives, the reactants for 2-substituted 1,3-benzoxazines, are synthesized by HCl hydrolysis from the typical benzoxazines. The phenol/aniline-based mono-oxazine benzoxazine, PH-a, and the bisphenol A/aniline-based bis-oxazine benzoxazine, BA-a, are used as examples to demonstrate the feasibility of this new approach. Their chemical structures are characterized by nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) and Raman spectroscopies, and are further verified by elementary analysis. Their thermal properties are studied by differential scanning calorimetry (DSC). These two 2-(aminomethyl) phenolic derivatives are reacted with paraformaldehyde to close the oxazine rings. A benzoxazine with a phenyl substituent at the 2-position of the oxazine ring is obtained from the 2-((phenylamino)methyl)phenol (hPH-a) and benzaldehyde. All these results highlight the success of the HCl hydrolysis and the formation of stable intermediates, namely 2-(aminomethyl) phenolic derivatives, from readily available benzoxazine monomers. This further demonstrates the feasibility of using these intermediates as reactants for a novel benzoxazine synthesis. Full article

(This article belongs to the Special Issue Ring Opening Polymerization: A Synthetic Toolbox for New Monomers and Polymers with Tailor-Made Properties and Functions)

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