Pub Date : 2019-09-09DOI: 10.1039/9781788016469-00065
Zhen Zhang, N. Hadjichristidis
Low-density polyethylene (LDPE) is indispensable for many applications in our everyday life due to its low cost, excellent physical properties, and easy processability. The rheological behavior that leads to this enhanced processability of LDPE is attributed to the presence of long chain branching (LCB). The linear versions of PE, namely high-density PE (HDPE), and linear low-density PE (LLDPE) both possess superior physical properties but poor processability. Since industrial PEs are not well-defined, model PEs with different branched macromolecular architectures are needed to understand the behavior of the different forms of PE and to improve their properties. Among them, star polymers consisting of several linear chains linked together to a central junction point have attracted the attention of scientists because they constitute the simplest form of branching. In this chapter, the strategies leading to well-defined PE stars from the mature anionic polymerization of butadiene and hydrogenation to the recently discovered polyhomologation (C1 polymerization) of dimethylsulfoxonium methylylide methods are presented. The ring-opening metathesis polymerization (ROMP) of monocyclic alkenes followed by hydrogenation and the Pd-diimine catalyzed “ethylene” polymerization towards PE stars are also briefly reviewed.
{"title":"CHAPTER 3. Precise Synthesis of Polyethylene-based Star Polymers: From Anionic Polymerization to Polyhomologation","authors":"Zhen Zhang, N. Hadjichristidis","doi":"10.1039/9781788016469-00065","DOIUrl":"https://doi.org/10.1039/9781788016469-00065","url":null,"abstract":"Low-density polyethylene (LDPE) is indispensable for many applications in our everyday life due to its low cost, excellent physical properties, and easy processability. The rheological behavior that leads to this enhanced processability of LDPE is attributed to the presence of long chain branching (LCB). The linear versions of PE, namely high-density PE (HDPE), and linear low-density PE (LLDPE) both possess superior physical properties but poor processability. Since industrial PEs are not well-defined, model PEs with different branched macromolecular architectures are needed to understand the behavior of the different forms of PE and to improve their properties. Among them, star polymers consisting of several linear chains linked together to a central junction point have attracted the attention of scientists because they constitute the simplest form of branching. In this chapter, the strategies leading to well-defined PE stars from the mature anionic polymerization of butadiene and hydrogenation to the recently discovered polyhomologation (C1 polymerization) of dimethylsulfoxonium methylylide methods are presented. The ring-opening metathesis polymerization (ROMP) of monocyclic alkenes followed by hydrogenation and the Pd-diimine catalyzed “ethylene” polymerization towards PE stars are also briefly reviewed.","PeriodicalId":20304,"journal":{"name":"Polymer science. Series A, Chemistry, physics","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81054066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-09DOI: 10.1039/9781788016469-00197
H. Cao, Xianhong Wang
This Chapter gives an overview of the advanced catalysis of CO2/epoxide copolymerization and the unique material properties of the resulting copolymers. Emphasis is placed on the hope of CO2 based copolymers, i.e. the poly(propylene carbonate) (PPC) family, including high-molecular-weight copolymers with alternative structures for the biodegradable plastics industry and low-molecular-weight CO2 polyols with non-alternative structures as new building blocks in the polyurethane industry. Delicate catalyst design for the copolymerization of CO2 and other functionalized epoxides, and multicomponent CO2 based copolymers with diversity are also briefly discussed.
{"title":"CHAPTER 7. Carbon Dioxide Copolymer From Delicate Metal Catalyst: New Structure Leading to Practical Performance","authors":"H. Cao, Xianhong Wang","doi":"10.1039/9781788016469-00197","DOIUrl":"https://doi.org/10.1039/9781788016469-00197","url":null,"abstract":"This Chapter gives an overview of the advanced catalysis of CO2/epoxide copolymerization and the unique material properties of the resulting copolymers. Emphasis is placed on the hope of CO2 based copolymers, i.e. the poly(propylene carbonate) (PPC) family, including high-molecular-weight copolymers with alternative structures for the biodegradable plastics industry and low-molecular-weight CO2 polyols with non-alternative structures as new building blocks in the polyurethane industry. Delicate catalyst design for the copolymerization of CO2 and other functionalized epoxides, and multicomponent CO2 based copolymers with diversity are also briefly discussed.","PeriodicalId":20304,"journal":{"name":"Polymer science. Series A, Chemistry, physics","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91106197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-09DOI: 10.1039/9781788016469-00089
Bo Qin, Jiangfei Xu, Xi Zhang
Supramolecular polymers are polymeric arrays of monomeric units that are connected together via highly directional and reversible noncovalent interactions, resulting in polymeric properties in solution and the bulk. Because of the dynamic nature of the noncovalent interactions, supramolecular polymers show distinct properties such as reversibility, self-healing, stimuli-responsiveness and good processability. Here, we provide an overview of the fabrication of supramolecular polymers. We introduce the driving forces for supramolecular polymerization, summarize the topological structures of supramolecular polymers, and highlight the methods and strategies for the fabrication of supramolecular polymers in a controllable manner. It is evident that supramolecular polymers based on noncovalent interactions are complementary to traditional polymer science and represent a new growth point by marrying supramolecular science with polymer science.
{"title":"CHAPTER 4. Fabrication of Supramolecular Polymers","authors":"Bo Qin, Jiangfei Xu, Xi Zhang","doi":"10.1039/9781788016469-00089","DOIUrl":"https://doi.org/10.1039/9781788016469-00089","url":null,"abstract":"Supramolecular polymers are polymeric arrays of monomeric units that are connected together via highly directional and reversible noncovalent interactions, resulting in polymeric properties in solution and the bulk. Because of the dynamic nature of the noncovalent interactions, supramolecular polymers show distinct properties such as reversibility, self-healing, stimuli-responsiveness and good processability. Here, we provide an overview of the fabrication of supramolecular polymers. We introduce the driving forces for supramolecular polymerization, summarize the topological structures of supramolecular polymers, and highlight the methods and strategies for the fabrication of supramolecular polymers in a controllable manner. It is evident that supramolecular polymers based on noncovalent interactions are complementary to traditional polymer science and represent a new growth point by marrying supramolecular science with polymer science.","PeriodicalId":20304,"journal":{"name":"Polymer science. Series A, Chemistry, physics","volume":"79 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76928660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-09DOI: 10.1039/9781788016469-00307
Jia-liang Yang, Chengjian Zhang, Xing-hong Zhang
In this chapter, we highlight the very recent advances in organocatalytic copolymerizations of carbon dioxide (CO2) and carbonyl sulfide (COS), two typical one-carbon (C1) building blocks. The organic catalyst systems for CO2(COS)/epoxide copolymerizations are intensively discussed. Organocatalysts perform well especially in the copolymerization of COS with epoxides. Fully alternating and regioselective COS-based copolymers with precise end groups can be produced. The synthesis of various types of CO2(COS)-based copolymers including block copolymers is also presented. In correspondence, the organocatalytic mechanism involving two C1 monomers is introduced. Furthermore, by generalizing the methods for C1/epoxide copolymerization, a “supramolecular anion” strategy is proposed for controlled/living anionic polymerizations, and successfully expanded to the controlled polymerization of PO for polyethers, ROP of γ-BL for polyesters and the copolymerization of PO with cyclic anhydrides for alternating polyesters. Finally, the properties of C1-based copolymers are introduced.
{"title":"CHAPTER 10. Organocatalytic Synthesis of CO2(COS)-based Copolymers","authors":"Jia-liang Yang, Chengjian Zhang, Xing-hong Zhang","doi":"10.1039/9781788016469-00307","DOIUrl":"https://doi.org/10.1039/9781788016469-00307","url":null,"abstract":"In this chapter, we highlight the very recent advances in organocatalytic copolymerizations of carbon dioxide (CO2) and carbonyl sulfide (COS), two typical one-carbon (C1) building blocks. The organic catalyst systems for CO2(COS)/epoxide copolymerizations are intensively discussed. Organocatalysts perform well especially in the copolymerization of COS with epoxides. Fully alternating and regioselective COS-based copolymers with precise end groups can be produced. The synthesis of various types of CO2(COS)-based copolymers including block copolymers is also presented. In correspondence, the organocatalytic mechanism involving two C1 monomers is introduced. Furthermore, by generalizing the methods for C1/epoxide copolymerization, a “supramolecular anion” strategy is proposed for controlled/living anionic polymerizations, and successfully expanded to the controlled polymerization of PO for polyethers, ROP of γ-BL for polyesters and the copolymerization of PO with cyclic anhydrides for alternating polyesters. Finally, the properties of C1-based copolymers are introduced.","PeriodicalId":20304,"journal":{"name":"Polymer science. Series A, Chemistry, physics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75783187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Synthetic Polymer Chemistry","authors":"","doi":"10.1039/9781788016469","DOIUrl":"https://doi.org/10.1039/9781788016469","url":null,"abstract":"","PeriodicalId":20304,"journal":{"name":"Polymer science. Series A, Chemistry, physics","volume":"208 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81224242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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