Dipolar HCP materials as alternatives to DMF solvent for azide-based synthesis

2021 ◽  
Author(s):  
Feng Gao ◽  
Rongxian Bai ◽  
Minghao Li ◽  
Yanlong Gu

Hypercrosslinked polymers HCP-DMF and HCP-DMF-SO3H that contains abundant and flexible DMF moieties were designed and synthesized. Benefitting from the solvation microenvironment provided by the pseudo-DMF moities, the polar HCPs manifested...

2019 ◽  
Author(s):  
Julio Ignacio Urzúa ◽  
Sandra Campana ◽  
Massimo Lazzari ◽  
Mercedes Torneiro

Tetraphenylmethane has emerged as a recurrent building block for advanced porous materials such as COFs, PAFs and hypercrosslinked polymers. Guided by a similar design principle, we have previously synthesized shape-persistent dendrimers with tetraphenylmethane nodes and ethynylene linkers. Here we report the generality of our approach by describing new dendritic architectures built from tetraphenylmethane. First, we prepared expanded dendrimers where the tetrahedral units are bonded through larger rigid rod spacers. Among the different synthetic strategies tested, the convergent route, with alternating steps of Pd-catalyzed Sonogashira coupling and alkyne activation by removal of TMS masking groups, efficiently afforded the first- and second-generation dendrimers. A second type of compounds having a linear diyne at the core is also described. The dendrimers of generations 1-2 were also synthesized by a convergent approach, with the diyne being assembled in the last step of the synthesis by a Glaser oxidative homocoupling of the corresponding dendrons bearing a terminal alkyne at the focal point. A third-generation dendrimer was also successfully prepared by a double-phase strategy.<br>


2021 ◽  
Author(s):  
Zishuai Wei ◽  
Qibin Chen ◽  
Honglai Liu

The removal of aniline from aqueous solution can have a major environmental impact and hence has attracted increasing attention in last years. In this work, four hypercrosslinked polymers (HCPs) bearing...


RSC Advances ◽  
2020 ◽  
Vol 10 (29) ◽  
pp. 17123-17128 ◽  
Author(s):  
Cijie Liu ◽  
Lijuan Zheng ◽  
Dexuan Xiang ◽  
Shasha Liu ◽  
Wei Xu ◽  
...  

A novel hypercrosslinked polymer-palladium catalyst was prepared via external cross-linking reactions and applied in Suzuki–Miyaura reactions as a recyclable catalyst, resulting in TON numbers up to 1.66 × 104 and yields reaching 99%.


2013 ◽  
Vol 535-536 ◽  
pp. 164-167
Author(s):  
Jonghun Yoon ◽  
Oana Cazacu ◽  
Jung Hwan Lee

In spite of this progress in predicting ductile failure, the development of macroscopic yield criteria for describing damage evolution in HCP (hexagonal close-packed) materials remains a challenge. HCP materials display strength differential effects (i.e., different behavior in tension versus compression) in the plastic response due to twinning. Cazacu and Stewart [1] developed an analytic yield criterion for a porous material containing randomly distributed spherical voids in an isotropic, incompressible matrix that displays tension-compression asymmetry. The matrix material was taken to obey the isotropic form of the Cazacu et al. [2] yield criterion, which captures the tension-compression asymmetry of the matrix material. In this paper, finite element calculations of a round tensile bar are conducted with the material behavior described by the Cazacu and Stewart [1] yield criterion. The goal of these calculations is to investigate the effect of the tension-compression asymmetry on the necking induced by void evolution and propagation.


2021 ◽  
Vol 104 (1) ◽  
pp. 1-9

Background: In the past decade, menstrual cups (MC) have become increasingly popular in many countries but there was no previous reporting on MC usage in Thailand. Objective: To evaluate and compare the satisfaction and acceptability of using MC and sanitary pads (SP) in health care personnel (HCP). Materials and Methods: Participants were HCP in Bhumibol Adulyadej Hospital who were willing to participate in the study between October 2019 and March 2020. They were randomly assigned into groups A and B. During the first three cycles of menstruation, participants in group A and B used SP and MC, respectively. In the later three cycles of menstruation, they were switched from SP to MC and vice versa. The demographic and menstrual characteristics were recorded. Satisfaction was evaluated by using the five-point Likert scale. Acceptability of MC usage was recorded on the sixth cycle questionnaire. Results: Ninety-eight HCP were recruited and equally divided into two groups (A and B). Acceptability for MC was significantly lower than SP (89 versus 100 percent, respectively). Participants who had regular sexual intercourse had more acceptability with MC than those who had no regular intercourse (98.4 versus 68.7 percent, respectively). Participants reported more significant satisfaction for MC than SP in terms of leakage prevention, cleaning, odor prevention, land activity, daily activity, comfortable sleep, and overall satisfaction. Contact dermatitis associated with MC was less than with SP with a statistically significant difference. Conclusion: Acceptability for MC was lower than SP. MC’s acceptability was preferred among HCPs with regular sexual intercourse. MC had higher satisfaction and less side effects than SP. Keywords: Acceptability, Menstrual cup, Menstruation, Sanitary pads, Satisfaction


Daxue Huaxue ◽  
2017 ◽  
Vol 32 (12) ◽  
pp. 1-11
Author(s):  
Wan-Kai AN ◽  
◽  
Lu-Lu WU ◽  
Qiu JIN ◽  
Li-Jun SHI ◽  
...  

2019 ◽  
Vol 55 (59) ◽  
pp. 8571-8574 ◽  
Author(s):  
Cher Hon Lau ◽  
Tian-dan Lu ◽  
Shi-Peng Sun ◽  
Xianfeng Chen ◽  
Mariolino Carta ◽  
...  

Hypercrosslinked polymers suitable for carbon capture were produced in continuous flow synthesis using 10% of the time required for typical batch reactions, precluding the need for lengthy reactions to produce microporous polymeric adsorbents.


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