Synthesis and characterization of anionic pentablock brush copolymers bearing poly(acrylic acid) side chains on the brush blocks separated by linear poly(butyl methacrylate) blocks

Krivorotova, Tatjana; Radzevicius, P.; Makuška, Ričardas

doi:10.1016/j.eurpolymj.2015.02.027

Cited by 10 publications

(6 citation statements)

References 68 publications

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“…Furthermore, the peaks corresponding to the singlet hydrogen (2 and 3) appeared around 2.5 and 2, respectively. The signal at 4.4 ppm is also assigned to the hydroxyl group (4) next to the carboxylate group . New signals are singlet, which elucidates the absence of coupling between hydrogens, supporting the proposed structure in Scheme .…”

Section: Resultsmentioning

confidence: 68%

Kraft Lignin–Tannic Acid as a Green Stabilizer for Oil/Water Emulsion

Gharehkhani

Ghavidel

Fatehi

2018

ACS Sustainable Chem. Eng.

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To overcome hydrophobicity and low charge density of kraft lignin (KL), softwood KL was reacted with tannic acid (TA), a green reagent, under alkaline conditions. The mechanism of this reaction was identified to proceed through three steps: (i) oxidation of TA, (ii) transesterification of ester groups of TA (in hydroquinone form) by lignin, and (iii) phenolic ring opening of TA. The enhancement in the carboxylate group was observed, resulting in KL–TA with a high charge density and water solubility in a wide pH range. The modified lignin was utilized as an emulsifier to stabilize oil (hexadecane) in water (O/W) emulations. Vertical scan analysis revealed the greater stability of the system against phase separation at low pH values. The stability of the emulsion containing KL–TA could be tuned by pH, while the emulsion containing lignosulfonate (LS) was not pH-responsive. The LS-containing emulsion had lower stability than the KL–TA-containing one. The rheological studies of KL–TA emulsions showed that all samples displayed shear-thinning characteristics.

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Section: Resultsmentioning

confidence: 68%

Kraft Lignin–Tannic Acid as a Green Stabilizer for Oil/Water Emulsion

Gharehkhani

Ghavidel

Fatehi

2018

ACS Sustainable Chem. Eng.

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“…Furthermore, bulky cyclic groups are known to terminate polymerisations and decrease kinetic chain lengths [ 17 ], resulting in shorter polymers, as seen here when the proportion of APMD in the feed is high ( Table 1 ). The polydispersity index for the polymers (Mw/number–average molecular weight (Mn)) ranges from 2.1 to 3.4, within typical ranges for free radical polymerization, but could be controlled by the terminating the polymerisation reaction at low conversion rates [ 18 ]. With the low synthetic yield of the AA/APMD (10:90) system, the copolymer prepared using a 30:70 monomer feed ratio was selected for skin permeation testing, and provided a system with a suitable repellent loading and with a molecular weight over 10-fold greater (6200 Da) than the notional upper molecular weight limit (~500 Da) for permeants to readily enter and diffuse through skin.…”

Section: Resultsmentioning

confidence: 99%

A Novel Polymer Insect Repellent Conjugate for Extended Release and Decreased Skin Permeation of Para-Menthane-3,8-Diol

2021

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Background: We developed a novel polymer insect repellent conjugate for extended release and decreased skin permeation of the volatile insect repellent p-menthane-3,8-diol (PMD). Methods: PMD was conjugated with acryloyl chloride via an ester bond to form acryloyl–PMD, which was subsequently copolymerised with acrylic acid at varying molar ratios. Copolymer structures were characterised by 1H NMR and FT-IR, analysed by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), molecular weights and reactivity ratios determined, and repellent loading assessed. Results: Using porcine liver esterases, ~45% of the insect repellent was released over five days. Penetration and permeation studies of the copolymer and free repellent using excised, full-thickness porcine ear skin showed no detectable permeation of the copolymer through skin compared to the PMD. Moreover, tape stripping revealed that over 90% of the copolymer remained on the outer surface of the skin, whereas free PMD was within all skin layers. A planarian toxicity fluorescence assay indicated that that the copolymer is unlikely to be a significant irritant when applied topically. Conclusions: this study demonstrates the feasibility of the copolymer approach to develop extended-release insect repellents while reducing skin uptake and transdermal permeation of the small-molecular-weight active ingredient, in order to minimise any adverse effects.

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“…Amylopectin has a hydroxyl group which may be substituted with ethyl alpha‐bromoisobutyrate to improve and facilitate the activities of amylopectin react with various types of alkyl methacrylate. The types of Alkyl methacrylate affect the grafting and compatibility of the synthetic polymer …”

Section: Introductionmentioning

confidence: 99%

“…The types of Alkyl methacrylate affect the grafting and compatibility of the synthetic polymer. [3][4][5] The hydroxyl groups of amylopectin were reacted with ethyl 2-bromoisobutyrate to prepare amylopectin macro initiator. The effect of the type of monomers on synthesis in the ATRP of Alkyl methacrylate has been investigated by % grafting, FTIR, NMR, TGA, DSC and SEM.…”

Section: Introductionmentioning

confidence: 99%

Grafting of Amylopectin With Various Alkyl Methacrylate by Atom Transfer Radical Polymerization for Engineering Application

Handayani

Chalid

Budianto

et al. 2017

Macromolecular Symposia

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Summary Amylopectin (Ap) was grafted with three different methacrylate by atom transfer radical polymerization (ATRP) to create controllable hydrophobic chain on amylopectin. The macro initiator Amylopectin‐Ethyl α‐bromoisobutyrate (Ap‐EBiB) was prepared by esterification of hydroxyl groups on amylopectin with Ethyl α‐Bromoisobutyrate (EBiB). In this research, amylopectin was grafted with methyl methacrylate (MMA), butyl methacrylate (BMA) and hexyl methacrylate (HMA) and the grafting conditions were optimized. Influence of grafting conditions on % monomer conversion, and % grafting efficiency were studied. Grafted samples were analyzed for their thermal behavior using thermo gravimetric analysis (TGA) and differential scanning calorimeter (DSC) and grafting was confirmed using nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). It was found that increasing length of alkyl chains increased grafting efficiency but improved the thermal behavior with better properties. The result of this study indicated that the Amylopectin‐g‐PHMA have % grafting higher than others.

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Synthesis and characterization of anionic pentablock brush copolymers bearing poly(acrylic acid) side chains on the brush blocks separated by linear poly(butyl methacrylate) blocks

Cited by 10 publications

References 68 publications

Kraft Lignin–Tannic Acid as a Green Stabilizer for Oil/Water Emulsion

Kraft Lignin–Tannic Acid as a Green Stabilizer for Oil/Water Emulsion

A Novel Polymer Insect Repellent Conjugate for Extended Release and Decreased Skin Permeation of Para-Menthane-3,8-Diol

Grafting of Amylopectin With Various Alkyl Methacrylate by Atom Transfer Radical Polymerization for Engineering Application

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