MacromoleculesPub Date : 2025-09-05DOI: 10.1021/acs.macromol.5c01418
Touseef Kazmi, , , Kyle S. Hepburn, , , Qamar Nisa, , , Swarnali Neogi, , , Nathaniel M. Bingham, , and , Peter J. Roth*,
{"title":"Single-Unit Comonomer Insertion Initiates Radical Polymerization of Thionolactone to Give Chemically and Thermally Degradable Polythioesters","authors":"Touseef Kazmi, , , Kyle S. Hepburn, , , Qamar Nisa, , , Swarnali Neogi, , , Nathaniel M. Bingham, , and , Peter J. Roth*, ","doi":"10.1021/acs.macromol.5c01418","DOIUrl":"10.1021/acs.macromol.5c01418","url":null,"abstract":"<p >Polythioesters are promising as sustainable materials with improved properties. But, despite the industrial importance of radical polymerization, polythioester homopolymers are not readily accessible through this method. Using dibenzo[<i>c</i>,<i>e</i>]oxepin-5(7H)-thione (DOT) as a thionolactone monomer, this study shows that the attempted radical homopolymerization suffers from low (3–13%) conversion. Conversely, addition of diethyl vinylphosphonate (DEVP), a judiciously chosen comonomer, led to near-quantitative DOT conversion at low (<22%) DEVP incorporation. Thorough analysis of the products by <sup>1</sup>H–<sup>1</sup>H COSY, <sup>1</sup>H–<sup>13</sup>C HMBC, and <sup>1</sup>H–<sup>31</sup>P HMBC NMR spectroscopy revealed that DEVP was inserted as single units and enabled the identification of DEVP repeat units sandwiched between two DOT groups (δ<sub>P</sub> = 24.5 ppm) and those located at the α end group between an AIBN-derived fragment and a DOT repeat unit (δ<sub>P</sub> = 23.7 ppm). The proportion of single DEVP repeat units at the α end group increased with a decreasing DEVP copolymerization feed, demonstrating the importance of the secondary DEVP-based radical in effectively initiating the polymerization of DOT. Polymers that carried, on average, less than one internal DEVP unit and consisted mostly of AIBN-DEVP-initiated DOT homopolymers were prepared by tuning the DEVP feed ratio. The polymers were fully degradable through aminolysis and by heating (in bulk) to 140 °C, with a higher DEVP content found to increase the formation of dibenzo[<i>c</i>,<i>e</i>]thiepin-5(7H)-one (DTO) thiolactone product during thermal degradation.</p>","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"58 18","pages":"9617–9628"},"PeriodicalIF":5.2,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acs.macromol.5c01418","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MacromoleculesPub Date : 2025-09-05DOI: 10.1021/acs.macromol.5c01047
Zhiyuan Cheng, , , Li Peng, , , Bo Yang, , , Hong Liu*, , , Jiajia Zhou*, , , Xianbo Huang*, , and , Guojie Zhang*,
{"title":"Synergy in Melting of Initially Disentangled Polymers: Linear versus Ring","authors":"Zhiyuan Cheng, , , Li Peng, , , Bo Yang, , , Hong Liu*, , , Jiajia Zhou*, , , Xianbo Huang*, , and , Guojie Zhang*, ","doi":"10.1021/acs.macromol.5c01047","DOIUrl":"10.1021/acs.macromol.5c01047","url":null,"abstract":"<p >Extensive molecular dynamics simulations of the Kremer–Grest model have been conducted to explore kinetic features and molecular mechanisms of the melting process of the initially disentangled linear and ring polymers with varying chain lengths (up to 800) in bulk, with an emphasis on illuminating the specific role of chain topology therein. In the meantime, some interesting issues concerning chain explosions have also been addressed in this study. It is revealed from our computational study that the melting of initially disentangled polymers, both linear ones and rings, is a three-stage process, where there is a synergy of such nonequilibrium processes as globule–coil transitions of polymer chains, polymer interpenetration, and thus formation of nontrivial topological states (i.e., entanglements or threadings) of polymers. We found that the melting of initially disentangled linear polymers seems to be accomplished through chain explosions, while such a picture is obscure for the ring case. In the linear case, it is through sufficient “releasing” of the two chain ends that the disentangled linear chains become able to explode for arriving at their well-equilibrated coil conformations, while chain expansion of ring polymers during the melting occurs with the aid of the formation of more wrinkled conformations due to the absence of chain ends. Moreover, it is concluded that a concomitant development of polymer interpenetrations essentially acts as a requisite for the occurrence of chain expansion during the melting, and a cooperation of chain expansion and interpenetrations leads to the emergence of entanglements in the linear systems and threadings in the rings.</p>","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"58 18","pages":"10164–10180"},"PeriodicalIF":5.2,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"SCFT-Guided Experimental Fabrication of Double-Diamond Structures in A1B/A2B Block Copolymer Binary Blends","authors":"Xinyu Wang, , , Yi Feng, , , Shuchen Lu, , , Xueyan Feng*, , , Guowei Wang*, , and , Weihua Li*, ","doi":"10.1021/acs.macromol.5c01972","DOIUrl":"10.1021/acs.macromol.5c01972","url":null,"abstract":"<p >It is well-known that neat AB linear diblock copolymers can form 3-fold double-gyroid (DG) bicontinuous tubular network nanostructures but cannot form thermodynamically stable 4-fold double-diamond (DD) structures. Although theoretical studies have suggested that blending homopolymers or homopolymer-like diblock copolymers into diblock copolymers can stabilize the DD structures in a wide region, experimentally achieving a stable DD structure in diblock copolymer systems still remains challenging. A series of previous studies has demonstrated that the binary blends composed of two A<sub>1</sub>B/A<sub>2</sub>B diblock copolymers with equal B-blocks but unequal A-blocks exhibit unique capability in stabilizing diverse nonclassical ordered structures by substantially shifting phase boundaries. In this work, we first employed self-consistent field theory (SCFT) to investigate the self-assembly behavior of the A<sub>1</sub>B/A<sub>2</sub>B blends and identified the parameters for stable DD structures. Our theoretical results reveal that the stability of DD structures is sensitive to the volume fraction of the AB diblock copolymers with shorter A-blocks, as well as sensitive to the length ratio of the two A-blocks. Guided by our theoretical predictions, we synthesized a number of polyisoprene-<i>b</i>-polystyrene (PI-<i>b</i>-PS) diblock copolymers. We subsequently blended diblock copolymers with varying polyisoprene (PI) lengths and investigated their self-assembled structures across various blending ratios. The DD structure was identified by small-angle X-ray scattering (SAXS) and confirmed by transmission electron microscopy (TEM). Our work demonstrates that experiments guided by reliable SCFT predictions can efficiently discover intriguing nonclassical nanostructures. In addition, our work confirms that this A<sub>1</sub>B/A<sub>2</sub>B binary blend possesses significant potential for stabilizing diverse novel structures.</p>","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"58 18","pages":"9776–9785"},"PeriodicalIF":5.2,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MacromoleculesPub Date : 2025-09-04DOI: 10.1021/acs.macromol.5c01789
William F. Drayer, , , Emily M. Duan, , , James C. Johnson, , , Karen I. Winey*, , and , Amalie L. Frischknecht*,
{"title":"Investigating Morphology and Diffusion in Simulations of Precise Anion-Conducting Polymers","authors":"William F. Drayer, , , Emily M. Duan, , , James C. Johnson, , , Karen I. Winey*, , and , Amalie L. Frischknecht*, ","doi":"10.1021/acs.macromol.5c01789","DOIUrl":"10.1021/acs.macromol.5c01789","url":null,"abstract":"<p >Using atomistic molecular dynamics simulations, we investigate the morphology and transport properties of a new class of polymers which are functionalized with quaternary ammonium groups for use as anion exchange membranes. The polymers are precision polyolefins with either a trimethylammonium (<i>p</i>5CNMe3) or a dimethyl-hexyl ammonium (<i>p</i>5CNMe2Hx) pendant group at every fifth carbon along a polyethylene backbone. Simulations are performed at hydration levels of 5, 10, 15, and 20 water molecules per ammonium group. The hydrated polymers form nanoscale, percolated hydrophilic domains (water channels) in the hydrophobic polymer matrix that become wider with increasing water content. Water and hydroxide anion diffusion coefficients also increase with increasing water content. The morphology of the water domains is similar in both polymers, while the diffusion coefficients are somewhat lower in <i>p</i>5CNMe2Hx at fixed water content. The diffusion coefficients in both polymers fall on the same curve as a function of the fractal dimension of the percolated water channels, which appears to be a useful scalar measure of the effects of the nanoscale morphology on water and hydroxide anion transport.</p>","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"58 18","pages":"10017–10025"},"PeriodicalIF":5.2,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144987518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Synthesis of Polyester-Polystyrene Hybrid Gel by PET-RAFT Polymerization in “RAFT Gel” and the Role of Dynamic Covalent Bonding in Its Self-Healing Properties","authors":"Shuji Yamada, , , Akinori Takasu*, , and , Hiroshi Eguchi, ","doi":"10.1021/acs.macromol.5c01490","DOIUrl":"10.1021/acs.macromol.5c01490","url":null,"abstract":"<p >We describe photoinduced electron/energy transfer reversible addition-fragmentation chain transfer (PET-RAFT) radical polymerization of styrene mediated by a gelatinous agent (“RAFT gel”). The resulting polymer possesses self-healing properties via dynamic covalent bonding. First, we synthesized poly[(butylene thiomalate)-<i>co</i>-(butylene adipate)] by chemoselective ternary polycondensation of thiomalic acid, adipic acid, and 1,4-butanediol. Next, we prepared gels in which cross-linking points are trithiocarbonates via the reaction of 1,1′-thiocarbonyldiimidazole with the pendant mercapto group in the parent polyesters. We named this type of gel, \"RAFT gel\" because the cross-linking points of the gel also act as RAFT agents. After swelling of this gel by a styrene monomer, we polymerized the monomer inside the gel by a PET-RAFT polymerization procedure triggered by irradiation with blue LED light for several hours catalyzed by tris(2-phenylpyridinato)iridium (III) [Ir(ppy)<sub>3</sub>] as a photoredox catalyst. A previously reported method initiated by 2,2′-azobis(isobutyronitrile) reported a poor grafting efficiency (ca. 50%), but it was dramatically improved (>99%) here by using the PET-RAFT technique. We also found that the polymerization rate using RAFT gel was faster than using a synthesized low-molecular-weight trithiocarbonate model RAFT agent, TTC-I. After a two-step degradation of the prepared gel via aminolysis and subsequent saponification, we characterized the number-averaged molecular weight of the branched poly(styrene)s. Additionally, we performed compression tests in order to evaluate the gel’s self-healing properties via dynamic covalent bonds, targeting a new type of photosensitive glue for poly(styrene) foams.</p>","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"58 18","pages":"9629–9635"},"PeriodicalIF":5.2,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144987305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MacromoleculesPub Date : 2025-09-04DOI: 10.1021/acs.macromol.5c01365
Ketong Su, , , Zuguang Yang, , , Weiping Liu, , , Shiyi Li, , , Ni Xiong, , , Cong Yu, , , Qian Li, , and , Rong Zeng*,
{"title":"Incorporation of Oxime Functionality into Polyolefins via Iron-Catalyzed C–H Imidoylation","authors":"Ketong Su, , , Zuguang Yang, , , Weiping Liu, , , Shiyi Li, , , Ni Xiong, , , Cong Yu, , , Qian Li, , and , Rong Zeng*, ","doi":"10.1021/acs.macromol.5c01365","DOIUrl":"10.1021/acs.macromol.5c01365","url":null,"abstract":"<p >Polyethylene (PE) and polypropylene (PP) are among the most widely produced macromolecular alkanes; however, there is an urgent need to introduce diverse functional groups into these materials to meet the demands of modern technologies. The incorporation of oxime functionality has garnered significant attention; however, the direct postfunctionalization to access such materials remains a considerable challenge. In this work, we report a mild iron-catalyzed method for the C–H imidoylation of polyethylene and polypropylene. This approach enables the efficient installation of oxime functionality into diverse commodities and postconsumer polyolefin plastics. New properties not found in virgin PP, such as enhanced hydrophilicity, improved compatibility in mixed plastic blends, and increased adhesion to aluminum and steel plates, are exhibited in these functionalized materials. These enhanced characteristics highlight great potential for further applications. Additionally, the successful use of real-world plastics offers a sustainable strategy to broaden the utilization of plastic waste.</p>","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"58 18","pages":"10048–10055"},"PeriodicalIF":5.2,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144987303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MacromoleculesPub Date : 2025-09-04DOI: 10.1021/acs.macromol.5c01840
Zhuang Wu, , , Masoumeh N. Salimi, , , Dean C. Webster, , , Andrew B. Croll, , and , Wenjie Xia*,
{"title":"Molecular Insights into the Interfacial Adhesion and Chain Adsorption of Silicone Polymers via Nanoindentation","authors":"Zhuang Wu, , , Masoumeh N. Salimi, , , Dean C. Webster, , , Andrew B. Croll, , and , Wenjie Xia*, ","doi":"10.1021/acs.macromol.5c01840","DOIUrl":"10.1021/acs.macromol.5c01840","url":null,"abstract":"<p >Silicone-based polymers, particularly polydimethylsiloxane (PDMS), are esteemed for their exceptional thermal stability, hydrophobicity, and biocompatibility. This study leverages atomistically informed coarse-grained molecular dynamics (CG-MD) simulations to explore the interfacial adhesive characteristics of PDMS films subjected to nanoindentation, with a focus on the influences of interfacial interaction strength between nanoindenter and polymer chains, temperature, and cross-link density, interpreted through the classic Johnson–Kendall–Roberts (JKR) model. Our findings reveal that increasing the interfacial interaction strength significantly enhances adhesion, necessitating a greater energy for separation. Notably, beyond a certain threshold, the adhesion exhibits a plateau, as quantified by the apparent critical energy release rate, <i>G</i><sub>c</sub>. This saturation in <i>G</i><sub>c</sub> can be attributed to chain adsorption on the indenter tip. Such an interfacial adsorption phenomenon becomes more pronounced at elevated temperatures along with a concomitant decrease in <i>G</i><sub>c</sub>, due to enhanced chain mobility. Additionally, increasing cross-link density of the PDMS network reduces chain adsorption during indentation, thereby resulting in a higher apparent <i>G</i><sub>c</sub>. Our simulation results, confirmed by the experimental Atomic Force Microscopy (AFM) measurements, offer valuable insights into interfacial behavior of silicone-based polymers, highlighting the intricate interplay among interaction strength, temperature, and cross-link density in quantifying adhesive properties of PDMS films.</p>","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"58 18","pages":"9763–9775"},"PeriodicalIF":5.2,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acs.macromol.5c01840","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144987432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MacromoleculesPub Date : 2025-09-04DOI: 10.1021/acs.macromol.5c01701
Haiyang Zhang, , , Sisi Ge, , , Weilong Gong, , , Jintian Luo*, , and , Biao Zuo*,
{"title":"Surface Dynamics of Polymer Glasses with Varying Chain Lengths","authors":"Haiyang Zhang, , , Sisi Ge, , , Weilong Gong, , , Jintian Luo*, , and , Biao Zuo*, ","doi":"10.1021/acs.macromol.5c01701","DOIUrl":"10.1021/acs.macromol.5c01701","url":null,"abstract":"<p >The surface dynamics of polymer glasses are complex due to strong coupling between the long-chain molecular structure and the surface mobility gradient. Herein, we investigated the surface relaxation of polymer glasses with varying chain lengths using an interfacial wetting-induced rheological (WIR) method. We identified rapid, Rouse-like motion on a short time scale, with activation energies independent of chain length, and slow, chain-dependent dynamics on a long time scale, with activation energies that increased with increasing chain length before attaining an asymptotic value. We attribute the former to the relaxation of the top strands of surface chains embedded in the surface mobility gradient and the latter to the relaxation of entire chains, which do not occur until the deepest segments of the surface chains are released. The findings of the study provide new insights into the hierarchical relaxation of interfacial polymers.</p>","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"58 18","pages":"9747–9753"},"PeriodicalIF":5.2,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144987301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MacromoleculesPub Date : 2025-09-03DOI: 10.1021/acs.macromol.5c01887
Michael-Phillip Smith, , , Lauren E. Ball, , , Ilanie Wessels, , and , Bert Klumperman*,
{"title":"Exploring the Removal of Thiocarbonylthio Chain Ends from Poly(styrene-alt-maleic anhydride) Copolymers","authors":"Michael-Phillip Smith, , , Lauren E. Ball, , , Ilanie Wessels, , and , Bert Klumperman*, ","doi":"10.1021/acs.macromol.5c01887","DOIUrl":"10.1021/acs.macromol.5c01887","url":null,"abstract":"<p >Poly(styrene-<i>alt</i>-maleic anhydride) (SMAnh), an alternating copolymer composed of electron-rich styrene (STY) and electron-deficient maleic anhydride (MAnh) comonomers, was synthesized via reversible addition–fragmentation chain transfer (RAFT)-mediated polymerization, using either a trithiocarbonate, dithiobenzoate, or dithiocarbamate chain transfer agent (CTA). SMAnh copolymers with different terminal repeat units (MAnh vs STY) were subjected to either radical-induced reduction or thermolysis to facilitate the transformation of the thiocarbonylthio functional chain end. The chemical composition of the ω-chain end and the solvency conditions employed during each end-group removal process were found to significantly influence the rate and extent of removal/transformation of the thiocarbonylthio functional group. MAnh-functional ω-chain ends enhanced the lability of the thiocarbonylthio group for all end-group removal strategies assessed, suggesting that electron-deficient chain ends facilitate higher efficiency removal of thiocarbonylthio functional groups. Additionally, 3,5-dimethyl pyrazole dithiocarbamate chain ends were reduced or thermolyzed faster and to a higher degree than trithiocarbonate- or dithiobenzoate-functional chain ends.</p>","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"58 18","pages":"10084–10093"},"PeriodicalIF":5.2,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/pdf/10.1021/acs.macromol.5c01887","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144931317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
MacromoleculesPub Date : 2025-09-03DOI: 10.1021/acs.macromol.5c01775
Ju Yong Park, , , Hyunjin Kim, , , Hye In Seo, , , Sangdeok Seo, , and , Bun Yeoul Lee*,
{"title":"Sulfur Treatment of Coordinative Chain Transfer Polymerization Products for Extending Polyolefin Chains with Polysulfide Linkages","authors":"Ju Yong Park, , , Hyunjin Kim, , , Hye In Seo, , , Sangdeok Seo, , and , Bun Yeoul Lee*, ","doi":"10.1021/acs.macromol.5c01775","DOIUrl":"10.1021/acs.macromol.5c01775","url":null,"abstract":"<p >Coordinative chain transfer polymerization (CCTP) is a state-of-the-art technology for producing olefin block copolymers. However, a key limitation of CCTP is its restricted molecular weight range achievable, as chain transfer reactions become inefficient when polyolefin chains attached to chain transfer agents exceed a certain length. This study presents a method for post-CCTP chain length extension, demonstrating that the reaction of CH<sub>3</sub>(CH<sub>2</sub>)<sub>5</sub>Zn(CH<sub>2</sub>)<sub>5</sub>CH<sub>3</sub> with S<sub>8</sub> quantitatively produces CH<sub>3</sub>(CH<sub>2</sub>)<sub>5</sub>–S<sub><i>x</i></sub>–(CH<sub>2</sub>)<sub>5</sub>CH<sub>3</sub> (<i>x</i> = 1–5). Treating S<sub>8</sub> to ethylene/propylene CCT<i>co</i>P products, i.e., (PEP)<sub>2</sub>Zn, synthesized using Et<sub>2</sub>Zn or (hexyl)<sub>2</sub>Zn, led to molecular weight (<i>M</i><sub>w</sub>) increases, though not doubling as anticipated. In contrast, treating (PEP)<sub>2</sub>Zn synthesized using (CH<sub>2</sub>═CHC<sub>6</sub>H<sub>4</sub>CH<sub>2</sub>CH<sub>2</sub>CH<sub>2</sub>)<sub>2</sub>Zn (<b>1</b>) resulted in significant <i>M</i><sub>w</sub> increases by 2.8–3.8 times, attributed to additional chain extension through the reaction of styrene end groups with S<sub>8</sub>. This approach enabled the synthesis of high <i>M</i><sub>w</sub> multiblock copolymers (200–400 kDa), chain-extended with –S<sub><i>x</i></sub>– linkages, from CCTP products such as (<i>i</i>PP-<i>b</i>-PEP)<sub>2</sub>Zn and (<i>i</i>PP-<i>b</i>-PE)<sub>2</sub>Zn. The resulting high-<i>M</i><sub>w</sub> polymers exhibited dramatically enhanced mechanical strength and viscosity showing pronounced shear thinning behavior compared to conventional acid-quenched CCTP products.</p>","PeriodicalId":51,"journal":{"name":"Macromolecules","volume":"58 18","pages":"9700–9711"},"PeriodicalIF":5.2,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144931318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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