Jéssica Bentes, Luciana Dutra, Ariane de J. Sousa-Batista, José Carlos Pinto
The demand for sustainable polymer particles production is growing, driven by the need for efficient, biocompatible, and biodegradable materials. In this context, the present study explores the production of poly(butylene succinate) (PBS) particles in a single step using a green heterogeneous suspension process, using vegetable oil as the suspending medium. Particularly, the effects of oil type (soybean, corn, sunflower), dispersed phase holdup (10–30 wt.%), stabilizers (Span 20, Span 80, Tween 80, Brij 52, Brij 93, Igepal-co-520, Polyglycerol polyricinoleate (PGPR)), reaction time (1–5 h), and temperature (100–160 °C) on the suspension polymerization are investigated. Results indicate that particle size and shape are influenced by the vegetable oil and stabilizer. Additionally, it is shown that the particle size distribution is affected by the use of a sonicator, allowing the manufacture of even smaller microsized particles. Based on the results, a 30 wt.% holdup in corn oil with a blend of surfactants can be recommended, producing spherical particles with an average diameter of 100 µm. Moreover, higher reaction temperatures (160 °C) and longer reaction times (5 h) positively impacted the molar mass of the obtained particles. Finally, cytotoxicity tests using Bone Marrow-Derived Macrophages cells confirmed the safe use of PBS microparticles at concentrations up to 1000 µg mL⁻¹
{"title":"Poly(butylene succinate) Microparticles Prepared Through Green Suspension Polycondensations","authors":"Jéssica Bentes, Luciana Dutra, Ariane de J. Sousa-Batista, José Carlos Pinto","doi":"10.1002/mren.202400022","DOIUrl":"https://doi.org/10.1002/mren.202400022","url":null,"abstract":"<p>The demand for sustainable polymer particles production is growing, driven by the need for efficient, biocompatible, and biodegradable materials. In this context, the present study explores the production of poly(butylene succinate) (PBS) particles in a single step using a green heterogeneous suspension process, using vegetable oil as the suspending medium. Particularly, the effects of oil type (soybean, corn, sunflower), dispersed phase holdup (10–30 wt.%), stabilizers (Span 20, Span 80, Tween 80, Brij 52, Brij 93, Igepal-co-520, Polyglycerol polyricinoleate (PGPR)), reaction time (1–5 h), and temperature (100–160 °C) on the suspension polymerization are investigated. Results indicate that particle size and shape are influenced by the vegetable oil and stabilizer. Additionally, it is shown that the particle size distribution is affected by the use of a sonicator, allowing the manufacture of even smaller microsized particles. Based on the results, a 30 wt.% holdup in corn oil with a blend of surfactants can be recommended, producing spherical particles with an average diameter of 100 µm. Moreover, higher reaction temperatures (160 °C) and longer reaction times (5 h) positively impacted the molar mass of the obtained particles. Finally, cytotoxicity tests using Bone Marrow-Derived Macrophages cells confirmed the safe use of PBS microparticles at concentrations up to 1000 µg mL⁻¹</p>","PeriodicalId":18052,"journal":{"name":"Macromolecular Reaction Engineering","volume":"18 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142861354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Transport of monomer from droplets to growing latex particles in emulsion polymerization in general is assumed to proceed via diffusion through the aqueous phase. Especially in miniemulsion polymerizations the direct transfer of very hydrophobic species from droplet to droplet is assumed to also proceed via collisions. Amongst the hydrophobic species where this is shown to play a role are monomers, initiators, inhibitors and (catalytic) chain transfer agents. It is well known that the reactor geometry and the stirring speed can have a profound effect on emulsion polymerizations. The 1972 paper of Nomura on the effect of stirring on emulsion polymerization is cited more than 100 times and until today keeps scientists intrigued. Diffusion limitations of monomer going from the droplet into the aqueous phase can occur for very hydrophobic monomers. The alternative route of transport via collisions is often not considered. In this perspective, paper will discuss the evidence for collision based transfer in miniemulsion polymerization and also consider whether collision based monomer transport can play a role in regular emulsion polymerizations.
{"title":"Monomer Transport by Collisions in (Mini) Emulsion Polymerization, a Personal Perspective","authors":"Alexander M. van Herk","doi":"10.1002/mren.202400013","DOIUrl":"https://doi.org/10.1002/mren.202400013","url":null,"abstract":"Transport of monomer from droplets to growing latex particles in emulsion polymerization in general is assumed to proceed via diffusion through the aqueous phase. Especially in miniemulsion polymerizations the direct transfer of very hydrophobic species from droplet to droplet is assumed to also proceed via collisions. Amongst the hydrophobic species where this is shown to play a role are monomers, initiators, inhibitors and (catalytic) chain transfer agents. It is well known that the reactor geometry and the stirring speed can have a profound effect on emulsion polymerizations. The 1972 paper of Nomura on the effect of stirring on emulsion polymerization is cited more than 100 times and until today keeps scientists intrigued. Diffusion limitations of monomer going from the droplet into the aqueous phase can occur for very hydrophobic monomers. The alternative route of transport via collisions is often not considered. In this perspective, paper will discuss the evidence for collision based transfer in miniemulsion polymerization and also consider whether collision based monomer transport can play a role in regular emulsion polymerizations.","PeriodicalId":18052,"journal":{"name":"Macromolecular Reaction Engineering","volume":"3 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigates polyaniline (PANI) for its sensing characteristics for detecting acetaldehyde. Pristine PANI is further modified in two ways to improve its sensing capabilities: 1) addition of a side chain (i.e., two methyl groups) to form poly (2,5‐dimethylaniline), 2) addition of small amounts of metal oxide dopant (In2O3 in this case) to PANI. All the materials are evaluated for their sensing characteristics with respect to both sensitivity and selectivity. The sensitivity of PANI toward acetaldehyde is found to improve with both types of modification (i.e., poly (2,5‐dimethylaniline) and PANI doped with different wt.% of In2O3). However, upon evaluating selectivity toward acetaldehyde using binary and ternary gas mixtures, pristine PANI exhibited higher selectivity compared to its modified counterparts.
本研究探讨了聚苯胺 (PANI) 检测乙醛的传感特性。原始 PANI 可通过两种方式进一步改性，以提高其传感能力：1) 添加侧链（即两个甲基）形成聚（2,5-二甲基苯胺），2) 在 PANI 中添加少量金属氧化物掺杂剂（本例中为 In2O3）。我们对所有材料的传感特性进行了评估，包括灵敏度和选择性。结果发现，PANI 对乙醛的灵敏度随着两种改性类型（即聚（2,5-二甲基苯胺）和掺杂不同重量百分比 In2O3 的 PANI）的增加而提高。不过，在使用二元和三元气体混合物评估对乙醛的选择性时，原始 PANI 的选择性高于其改性后的同类产品。
{"title":"Tailoring Polyaniline for Improved Acetaldehyde Detection","authors":"Bhoomi Het Mavani, Alexander Penlidis","doi":"10.1002/mren.202400018","DOIUrl":"https://doi.org/10.1002/mren.202400018","url":null,"abstract":"This study investigates polyaniline (PANI) for its sensing characteristics for detecting acetaldehyde. Pristine PANI is further modified in two ways to improve its sensing capabilities: 1) addition of a side chain (i.e., two methyl groups) to form poly (2,5‐dimethylaniline), 2) addition of small amounts of metal oxide dopant (In<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> in this case) to PANI. All the materials are evaluated for their sensing characteristics with respect to both sensitivity and selectivity. The sensitivity of PANI toward acetaldehyde is found to improve with both types of modification (i.e., poly (2,5‐dimethylaniline) and PANI doped with different wt.% of In<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>). However, upon evaluating selectivity toward acetaldehyde using binary and ternary gas mixtures, pristine PANI exhibited higher selectivity compared to its modified counterparts.","PeriodicalId":18052,"journal":{"name":"Macromolecular Reaction Engineering","volume":"11 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2024-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142208553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shen Li, Zhong-Xin Liu, Yin-Ning Zhou, Zheng-Hong Luo
The effect of solvents on kinetic parameters of anionic polymerization is complex and a comprehensive theoretical study has been rare. In this work, four solvent polarity descriptors (i.e., polarizability, dipole moment, nucleophilic index, electrophilic index) are correlated with solvent parameters (Ea, A, ΔH‡, and ΔS‡) by multiple linear regression using the Catalan linear free-energy relationship (LFER) equation for the anionic polymerization of styrene. The results show that Ea, ΔH‡, and ΔS‡ have a low correlation with dipole moment, whereas A is strongly correlated with dipole moment. Given the fact that the larger A the larger effective collision frequency Z, it is hypothesized that in polar solvents, the polymer chains are more extended, enabling more effective collisions between monomers and active anionic species during polymerization. In contrast, in nonpolar solvents, the polymer chains collapse, making it more difficult for the monomer to be inserted into the ion pairs. Subsequently, n-pentane and tetrahydrofuran are chosen as representatives to confirm this conjecture by molecular simulations. Lastly, Ea, A and kp are predicted for 173 solvents using well-established descriptive relationships.
溶剂对阴离子聚合动力学参数的影响非常复杂，目前还很少有全面的理论研究。本研究采用加泰罗尼亚线性自由能关系（LFER）方程，通过多元线性回归，将苯乙烯阴离子聚合反应中的四个溶剂极性描述因子（即极化性、偶极矩、亲核指数、亲电指数）与溶剂参数（Ea、A、ΔH‡ 和 ΔS‡）相关联。结果表明，Ea、ΔH‡ 和 ΔS‡ 与偶极矩的相关性较低，而 A 与偶极矩的相关性较高。鉴于 A 越大，有效碰撞频率 Z 越大这一事实，可以推测在极性溶剂中，聚合物链延伸得越长，聚合过程中单体和活性阴离子物质之间的碰撞就越有效。相反，在非极性溶剂中，聚合物链会塌陷，使单体更难插入离子对中。随后，我们选择了正戊烷和四氢呋喃作为代表，通过分子模拟来证实这一猜想。最后，利用成熟的描述关系预测了 173 种溶剂的 Ea、A 和 kp。
{"title":"Determining the Kinetic and Thermodynamic Parameters of Anionic Polymerization of Styrene Using Linear Free-Energy Relationship","authors":"Shen Li, Zhong-Xin Liu, Yin-Ning Zhou, Zheng-Hong Luo","doi":"10.1002/mren.202400021","DOIUrl":"10.1002/mren.202400021","url":null,"abstract":"<p>The effect of solvents on kinetic parameters of anionic polymerization is complex and a comprehensive theoretical study has been rare. In this work, four solvent polarity descriptors (i.e., polarizability, dipole moment, nucleophilic index, electrophilic index) are correlated with solvent parameters (<i>E<sub>a</sub></i>, <i>A</i>, Δ<i>H</i>‡, and Δ<i>S</i>‡) by multiple linear regression using the Catalan linear free-energy relationship (LFER) equation for the anionic polymerization of styrene. The results show that <i>E<sub>a</sub></i>, Δ<i>H</i>‡, and Δ<i>S</i>‡ have a low correlation with dipole moment, whereas <i>A</i> is strongly correlated with dipole moment. Given the fact that the larger <i>A</i> the larger effective collision frequency <i>Z</i>, it is hypothesized that in polar solvents, the polymer chains are more extended, enabling more effective collisions between monomers and active anionic species during polymerization. In contrast, in nonpolar solvents, the polymer chains collapse, making it more difficult for the monomer to be inserted into the ion pairs. Subsequently, n-pentane and tetrahydrofuran are chosen as representatives to confirm this conjecture by molecular simulations. Lastly, <i>E<sub>a</sub></i>, <i>A</i> and <i>k<sub>p</sub></i> are predicted for 173 solvents using well-established descriptive relationships.</p>","PeriodicalId":18052,"journal":{"name":"Macromolecular Reaction Engineering","volume":"18 6","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141922999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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