On the Thermal Self-Initiation Reaction of n-Butyl Acrylate in Free-Radical Polymerization

Riazi, Hossein; Shamsabadi, Ahmad Arabi; Corcoran, Patrick; Grady, Michael C.; Rappe, Andrew M.; Soroush, Masoud

doi:10.3390/pr6010003

Cited by 24 publications

(23 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, the two singlets at 5.80 and 6.20 ppm recall the pattern of geminal hydrogens of a substituted double bond and were tentatively attributed to radical reactions between the acrylamide terminals formed in each retro-aza-Michael step. Radical dimerizations are, for instance, the basis of spontaneous thermal and photochemical self-polymerization of vinyl monomers [ 57 , 58 , 59 , 60 ]. It may be observed that the degrading samples were purposely maintained for months in natural conditions of temperature and light.…”

Section: Discussionmentioning

confidence: 99%

Highlight on the Mechanism of Linear Polyamidoamine Degradation in Water

et al. 2020

View full text Add to dashboard Cite

This paper aims at elucidating the degradation mechanism of linear polyamidoamines (PAAs) in water. PAAs are synthesized by the aza-Michael polyaddition of prim-monoamines or bis-sec-amines with bisacrylamides. Many PAAs are water-soluble and have potential for biotechnological applications and as flame-retardants. PAAs have long been known to degrade in water at pH ≥ 7, but their degradation mechanism has never been explored in detail. Filling this gap was necessary to assess the suitability of PAAs for the above applications. To this aim, a small library of nine PAAs was expressly synthesized and their degradation mechanism in aqueous solution studied by 1H-NMR in different conditions of pH and temperature. The main degradation mechanism was in all cases the retro-aza-Michael reaction triggered by dilution but, in some cases, hints were detected of concurrent hydrolytic degradation. Most PAAs were stable at pH 4.0; all degraded at pH 7.0 and 9.0. Initially, the degradation rate was faster at pH 9.0 than at pH 7.0, but the percent degradation after 97 days was mostly lower. In most cases, at pH 7.0 the degradation followed first order kinetics. The degradation rates mainly depended on the basicity of the amine monomers. More basic amines acted as better leaving groups.

show abstract

Section: Discussionmentioning

confidence: 99%

Highlight on the Mechanism of Linear Polyamidoamine Degradation in Water

et al. 2020

View full text Add to dashboard Cite

show abstract

“…There was no need to use an initiator. AAc has high tendency for thermal self-initiation in bulk [36,37] and H 2 SO 4 has an accelerating effect on its polymerization. [38] Also, any solvent was not used in the preparation of the pregel solution because AAc and TX-100 were homogeneously miscible with each other.…”

Section: Hydrogel Preparation Swelling and Gel Fraction Measurementsmentioning

confidence: 99%

Micelle Crosslinked Polyacrylic Acid Hydrogels with Resilience and Self‐Recovery Properties

Gulyuz

2020

Macro Materials & Eng

View full text Add to dashboard Cite

Micelle crosslinking method is one of the several techniques to fabricate hydrogels with good mechanical performance. Micelle crosslinked hydrogels reported so far are fabricated using a multistep preparation process due to the functionalization of block copolymers or surfactants with acrylate, aldehyde, azo, or reversible addition‐fragmentation chain transfer groups to create a polymer network. Herein, a simple one‐step approach is introduced to produce resilient hydrogels prepared by bulk polymerization of acrylic acid and esterification with Triton X‐100 (TX‐100) in the presence of catalyst sulfuric acid (H2SO4). The advantage of this study is that TX‐100 surfactants self‐assembling into micelles are directly bonded onto polymer chains through an ester bond without any further modification. The obtained hydrogels exhibit tensile strengths up to 135 ± 8 kPa and compressive strengths up to 16 ± 1 MPa over 94% strains as well as complete self‐recovery and high resilience abilities (≈86% at strains up to 400%) originating from hydrophobic associations in the core of micelles acting as dynamic cross‐linkers along with hydrogen bonds and entanglements between polymer chains acting as additional crosslink points. The overall results show that the hydrogels can be good candidate as elastic materials in many fields.

show abstract

“…The Special Issue also contains two contributions focusing on polymerization processes. One paper investigates the experimental validation of a kinetic model for thermal spontaneous polymerization of n-butyl acrylate) [13], while the other paper presents a MATLAB-based tool for copolymerization reactivity ratio estimation based on error-in-variables models [14]. The sixth paper in this area addresses the problem of materials processing through the development of a classification method for identifying a promising experimental design region from a literature database [15].…”

Section: Materials Processesmentioning

confidence: 99%