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1.
Javier Illescas Yessica S. Ramírez‐Fuentes Gerardo Zaragoza‐Galán Pasquale Porcu Alberto Mariani Ernesto Rivera 《Journal of polymer science. Part A, Polymer chemistry》2015,53(24):2890-2897
Frontal polymerization (FP) of poly(ethylene glycol) diacrylate (PEGDA) was carried out using benzoyl peroxide (BPO) as radical initiator. In addition, a pyrene containing monomer, 1‐pyrenebutyl acrylate (PyBuAc), was incorporated as a fluorescent probe in order to obtain luminescent materials with different chromophore contents. The resulting polymers were characterized by FT‐IR spectroscopy in the solid state and their thermal properties were determined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Moreover, the optical properties of these materials were studied by absorption and fluorescence spectroscopy. The maximum amount of the incorporated pyrene‐containing monomer into the polymer matrix was limited to 1 wt % by the polymerization process. The obtained labeled polymers poly(PEGDA‐co‐PyBuAc) exhibited a broad absorption band at 345 nm. The fluorescence spectra of these polymers exhibited mainly “monomer emission” so that no excimer emission was observed. It is possible to tune the color of the emitted light by varying the pyrene content in the samples. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2890–2897 相似文献
2.
Luís A. S. A. De Prado Iris L. Torriani Inez V. P. Yoshida 《Journal of polymer science. Part A, Polymer chemistry》2010,48(5):1220-1229
Self‐supported translucent films constituted of poly(n‐octylsilsesquioxane) or poly(n‐dodecylsilsesquioxane) were obtained from the hydrolysis and condensation of n‐octyltriethoxysilane (OTES) or n‐dodecyltriethoxysilane (DTES), respectively. Dense films were obtained in the absence of organic solvents, with dibutyltin diacetate as catalyst. These films exhibited good optical transparency and thermal stability. The incorporation of oligomeric dimethylsiloxane units (DMe,Me) in these materials, derived from silanol‐terminated poly(dimethylsiloxane) (PDMS) or 1,1,3,3‐tetramethyl‐1,3‐diethoxydisiloxane (TMDES), was carried out during the hydrolysis and condensation of OTES and DTES and was confirmed by solid‐state 29Si NMR. Poly(n‐octylsilsesquioxane) showed a glass‐transition temperature at ?65 °C, due to the increase in the free volume, promoted by the bulky n‐octyl groups. The differential scanning calorimetric (DSC) curves of the polymer derived from DTES were characterized by first‐order transitions at temperatures ranging from ?15.8 to ?0.7 °C. Further studies of these networks by low‐temperature XRD evidenced narrowing of the diffraction halos suggesting a partial order–disorder transition for these materials at lower temperatures. Good thermal stability up to 350 °C and the solvent‐free production process make these polymers potential candidates for the development of self‐supported hydrophobic protective coatings. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1220–1229, 2010 相似文献
3.
Thermal transitions in epoxy networks prepared by reaction of α, ω‐diamino terminated poly(propylene oxide)‐block‐poly(ethylene oxide)‐block‐poly(propylene oxide) and diglycidyl ether of brominated Bisphenol A, swollen in water, were studied by differential scanning calorimetry (DSC) in a broad temperature range (from ?100 °C to 20 °C). Networks of two different values of initial molar ratio of amino and epoxy groups were prepared, r (r = 1.00, 2.00), and swollen with different amounts of water up to equilibrium concentration values. The qualitatively different kinds of experimental thermograms have been obtained for two networks and classified according to the amount of water in the sample on the basis of the phase diagram of the system. Also, the concentration dependence of the curves in this diagram (glass transition, melting, and crystallization) as well as the fraction of noncrystallizable water supply some information about the morphology of the system. In this sense, the existence of a microphase separated structure of swollen networks is suggested. The structure consists of hydrophilic and hydrophobic domains and depends on the initial molar ratio of the reactive groups. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 699–708, 2005 相似文献
4.
Zhixian Xu Suyun Jie Bo‐Geng Li 《Journal of polymer science. Part A, Polymer chemistry》2014,52(22):3205-3212
Well‐defined diblock copolymers of linear polyethylene (PE) and poly(dimethylsiloxane) (PDMS) have been synthesized through a facile route combining the thiol‐ene click chemistry of vinyl‐terminated polyethylene (PE‐ene) and the sequential esterification reaction. The resulting diblock copolymers are characterized by 1H NMR, FT‐IR, DSC, TGA, and TEM. In addition, the PE‐b‐PDMS diblock copolymers have been evaluated as compatibilizers in the blends of high‐density polyethylene (HDPE) and silicone oil. The morphological analysis and mechanical properties demonstrate that the compatibilized blends with low loading concentration of PE‐b‐PDMS display significant improvements in modulus of elasticity and elongation at break as compared to the uncompatibilized binary blends. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3205–3212 相似文献
5.
Breathable rubbery skin protectors: Design,synthesis, characterization,and properties of cyanoacrylated silicone rubber networks
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Amalia Szanka Istvan Szanka Joseph P. Kennedy 《Journal of polymer science. Part A, Polymer chemistry》2016,54(10):1367-1372
We extended our investigations of rubbery wound closure adhesives and created novel flexible networks by crosslinking cyanoacrylated silicone rubbers (i.e., commercial methylhydrosiloxane‐dimethylsiloxane copolymers, PMHS‐co‐PDMS) with N,N‐dimethyl‐p‐toluidine in tetrahydrofuran and hexamethyldisiloxane solvents at room temperature. Cyanoacrylation was achieved by hydrosilating (anthracene‐protected) allyl cyanoacrylate with PMHS‐co‐PDMS. Steric hindrance and the molecular weight of the copolymer strongly affect the extent of hydrosilation. The rate of crosslinking is proportional with the number of cyanoacrylate groups in the copolymer and networks form in seconds with appropriate amounts of initiator. Networks on porcine skin yield well‐adhering flexible optically‐transparent colorless conformal coatings of good “feel” appropriate for clinically useful non‐occlusive “breathable” skin or wound protectors. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1367‐1372 相似文献
6.
Ju‐Myung Song Sun‐Young Lee Hyun‐Su Woo Joon‐Yong Sohn Junhwa Shin 《Journal of Polymer Science.Polymer Physics》2014,52(7):517-525
The effect of the degree of grafting (DOG) on the thermal behavior of poly(vinylbenzyl chloride)‐grafted poly(ethylene‐co‐tetrafluoroethylene) (ETFE‐g‐PVBC) films was investigated by differential scanning calorimetry (DSC), X‐ray diffraction (XRD), dynamic mechanical analysis ( DMA), FT‐IR, and thermogravimetric analysis (TGA) instruments. Several ETFE‐g‐PVBC films with various degrees of grafting, including 10, 24, 41, 60, and 94%, were prepared using a radiation grafting technique. The DSC and XRD results of the ETFE‐g‐PVBC films revealed that the crystallinity of the films decreased as the DOG increased. The DMA and FT‐IR results of the films indicated that a crosslinking reaction occurred at temperatures above 250 °C. In the thermal properties of the grafted films, an increase in the DOG led to an increase in the decomposition temperature. The activation energy (Ea) of the thermal decomposition was calculated using Kissinger's equation from TGA results. The Ea value of the PVBC graft chain was found to increase as the DOG increased, indicating that the crosslinking reaction of ETFE‐g‐PVBC films increased with an increase in the DOG during the thermal degradation process. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 517–525 相似文献
7.
Liangliang Qu Zhijian Xie Guangsu Huang Zhenhua Tang 《Journal of Polymer Science.Polymer Physics》2008,46(16):1652-1659
The relaxation behaviors of poly(dimethylsiloxane‐co‐diphenylsiloxane)s with different compositions were investigated using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC). It is indicated that the content of Ph2SiO unit, which is closely associated with crystallinity of polysiloxane, has a remarkable influence on its relaxation behavior. Two‐phase (crystalline and amorphous phase) structure in the semicrystalline polysiloxane of the present system can be determined for discussing relaxation behavior. An increase in relaxation strength can be reasoned to a cooperative effect of decrease in fraction of crystalline phase and increase in friction between molecular chains. And enhancements in glass transition temperature (Tg) and effective activation energy for glass transition (Ea(eff)) were ascribed more to the stiffness imposed by Ph2SiO unit than decrease in fraction of crystalline phase. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1652–1659, 2008 相似文献
8.
Makoto Muranaka Tsutomu Ono 《Journal of polymer science. Part A, Polymer chemistry》2009,47(20):5230-5240
Monodisperse poly(D ,L ‐lactide) (PDLLA) microspheres were prepared by dispersion polymerization of D ,L ‐lactide in xylene/heptane (1/2, v/v) with poly[(dodecyl methacrylate)‐co‐(2‐hydroxyethyl methacrylate)] (P(DMA‐co‐HEMA)) as a dispersion stabilizer. P(DMA‐co‐HEMA) contains hydroxy groups, which act as an initiation group for pseudoanionic dispersion polymerization. The best coefficient of variation (CV) values concerning particle diameter distribution and the particle diameter of obtained PDLLA microspheres were 3.7% and 5.3 μm, respectively. The particle diameter decreased with increasing concentration of P(DMA‐co‐HEMA) and HEMA maintained low CV (<10%) values. As a result, monodisperse PDLLA microspheres ranging from 1.3 to 5.3 μm were obtained. In addition, it was found that monodisperse PDLLA microspheres were obtained by sufficient capture of growing polymers and monomers in the particle growth stage. Therefore, the HEMA concentration in P(DMA‐co‐HEMA) strongly affecting the capturing capability is the most important factor. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5230–5240, 2009 相似文献
9.
Bayar Hexig Yong He Naoki Asakawa Yoshio Inoue 《Journal of Polymer Science.Polymer Physics》2004,42(16):2971-2982
Miscibility and hydrogen bonding interaction have been investigated for the binary blends of poly(butylene adipate‐co‐44 mol % butylene terephthalate)[P(BA‐co‐BT)] with 4,4'‐thiodiphenol (TDP) and poly(ethylene‐ oxide)(PEO) with TDP; and the ternary blends of P(BA‐co‐BT)/PEO/TDP by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The DSC results indicated that the binary blends of P(BA‐co‐BT)/TDP and PEO/TDP were miscible because each blend showed only one composition‐dependent glass‐transition over the entire range of the blend composition. The formation of intermolecular hydrogen bonds between the hydroxyl groups of TDP and the carbonyl groups of P(BA‐co‐BT), and between the hydroxyl groups of TDP and the ether groups of PEO was confirmed by the FTIR spectra. According to the glass‐transition temperature measured by DSC, P(BA‐co‐BT) and PEO, their binary blends were immiscible over the entire range of blend composition, however, the miscibility between P(BA‐co‐BT) and PEO was enhanced through the TDP‐mediated intermolecular hydrogen bonding interaction. It was concluded that TDP content of about 5–10% may possibily enhance miscibility between P(BA‐co‐BT) and PEO via a hydrogen bonding interaction. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2971–2982, 2004 相似文献
10.
Elvira Vidović Doris Klee Hartwig Höcker 《Journal of polymer science. Part A, Polymer chemistry》2007,45(19):4536-4544
Poly(D ,L ‐lactide) and poly(D ,L ‐lactide‐co‐glycolide) with various composition and with one methacrylate and one carboxylate end group were synthesized and grafted onto poly(vinyl alcohol) (PVA) via the carboxylate group. The graft copolymers were crosslinked via the methacrylate groups using a free radical initiator. The polymer networks were characterized by means of NMR and studied qualitatively by means of IR spectroscopy. The influence of the glycolide content in the polyester grafts and of the number of ester units in the grafts on thermal properties and swellability were studied as well. The high swellability in water is characteristic of all hydrogels. Differential scanning calorimetry (DSC) showed a single glass transition temperature that occurs in the range between 51 and 69 °C. Thermogravimetric analysis (TGA) of the networks showed the main loss in weight in the temperature range between 290 and 370 °C. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4536–4544, 2007 相似文献
11.
Nese Cakir Merve Yavuzarslan Hakan Durmaz Gurkan Hizal Umit Tunca 《Journal of polymer science. Part A, Polymer chemistry》2013,51(4):899-907
In this study, an equimolar mixture of oxanorbornenyl‐anthracene (ONB‐anthracene), oxanorbornenyl‐bromide (ONB‐Br), and oxanorbornenyl tosylate (ONB‐OTs) was polymerized via ring opening metathesis polymerization using the first generation Grubbs' catalyst in CH2Cl2 at room temperature to form poly(ONB‐anthracene‐co‐ONB‐Br‐co‐ONB‐OTs)10 copolymer as a main backbone. Next, this main backbone was sequentially clicked with a furan protected maleimide‐terminated poly(methyl methacrylate), 2,2,6,6‐tetramethyl‐1‐piperidinyloxy‐terminated poly(ethylene glycol), and alkyne‐terminated poly(ε‐caprolactone) (PCL20‐alkyne) via Diels–Alder, nitroxide radical coupling, and copper‐catalyzed azide‐alkyne cycloaddition, respectively, to yield a poly(ONB‐g‐PMMA‐co‐ONB‐g‐PEG‐co‐ONB‐g‐PCL)10 heterograft brush copolymer © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
12.
Sung‐Young Park Hee‐Young Park Hwa‐Soo Lee Sang‐Wook Park Chang‐Sik Ha Dae‐Won Park 《Journal of polymer science. Part A, Polymer chemistry》2001,39(9):1472-1480
This study was related to the investigation of the chemical fixation of carbon dioxide to a copolymer bearing epoxide and the application of the cyclic carbonate group containing copolymer‐to‐polymer blends. In the synthesis of poly[(2‐oxo‐1,3‐dioxolane‐4‐yl) methyl methacrylate‐co‐ethyl acrylate] [poly(DOMA‐co‐EA)] from poly(glycidyl methacrylate‐co‐ethyl acrylate) [poly(GMA‐co‐EA)] and CO2, quaternary ammonium salts showed good catalytic activity. The films of poly(DOMA‐co‐EA) with poly(methyl methacrylate) (PMMA) or poly(vinyl chloride) (PVC) blends were cast from N,N′‐dimethylformamide solution. The miscibility of the blends of poly(DOMA‐co‐EA) with PMMA or PVC have been investigated both by DSC and visual inspection of the blends. The optical clarity test and DSC analysis showed that poly(DOMA‐co‐EA) containing blends were miscible over the whole composition range. The miscibility behaviors were discussed in terms of Fourier transform infrared spectra and interaction parameters based on the binary interaction model. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1472–1480, 2001 相似文献
13.
Muhammad Irfan Xiang‐Yun Du Xu Ran Xu Rui Qi Shen Su Chen Ji Jun Xiao 《Journal of polymer science. Part A, Polymer chemistry》2019,57(22):2214-2221
In this work, we report a series of poly(itaconic acid‐co‐acrylic acid‐co‐acrylamide) (poly(IA‐co‐AAc‐co‐AAm)) hydrogels via frontal polymerization (FP). FP starts on the top of the reaction mixture with aid of heating provided from soldering iron gun. Once polymerization initiated, no further energy is required to complete the process. The influences of IA/AAc weight ratios on frontal velocities, temperatures, and conversions on the reaction time are thoroughly investigated and discussed where the amount of AAm monomer remains constant. Fourier transform‐infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscope (SEM), dynamic mechanical analysis, and the swelling measurement are applied to characterize the as‐synthesized poly(IA‐co‐AAc‐co‐AAm) hydrogels. Interestingly, the swelling ratios of the hydrogels are changed with different IA/AAc contents, and the maximum swelling ratios are ~4439% in water. SEM images describe highly porous morphologies and explain good swelling capabilities. Moreover, the poly(IA‐co‐AAc‐co‐AAm) hydrogels exhibit superior pH‐responsive ability. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2214–2221 相似文献
14.
Jean‐Franois Lutz Andreas F. Thünemann Rainer Nehring 《Journal of polymer science. Part A, Polymer chemistry》2005,43(20):4805-4818
The radical polymerization of three monomers bearing nucleobases 1‐(4‐vinylbenzyl)thymine (VBT), 1‐(4‐vinylbenzyl)uracil (VBU) and 9‐(4‐vinylbenzyl)adenine (VBA) was investigated. The corresponding homopolymers could be prepared in high yields via conventional radical polymerization. However, the resulting polymers were found to be only soluble in a few polar solvents. On the other hand, copolymers of dodecyl methacrylate (DMA) with either VBT or VBA could be prepared via both free radical polymerization and atom transfer radical polymerization and could be dissolved in a large variety of organic solvents. Moreover, the formed complementary copolymers P(VBT‐co‐DMA) and P(VBA‐co‐DMA) were found to self‐assemble in dilute solutions in dioxane or chloroform via base recognition, as evidenced by a significant hypochromicity effect in UV spectroscopy. Nevertheless, at higher concentrations in chloroform, both dynamic light scattering and optical microscopy indicate that P(VBT‐co‐DMA), P(VBA‐co‐DMA), or P(VBT‐co‐DMA)/P(VBA‐co‐DMA) mixtures spontaneously self‐assemble into micron size spherical aggregates. 1H NMR and FTIR studies confirmed that the self‐assembly process is driven in all cases via H‐bond formation. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4805–4818, 2005 相似文献
15.
Zhigang Xie Changhai Lu Xuesi Chen Li Chen Yu Wang Xiuli Hu Quan Shi Xiabin Jing 《Journal of polymer science. Part A, Polymer chemistry》2007,45(9):1737-1745
Novel poly(ester carbonate)s were synthesized by the ring‐opening polymerization of L ‐lactide and functionalized carbonate monomer 9‐phenyl‐2,4,8,10‐tetraoxaspiro[5,5]undecan‐3‐one derived from pentaerythritol with diethyl zinc as an initiator. 1H NMR analysis revealed that the carbonate content in the copolymer was almost equal to that in the feed. DSC results indicated that Tg of the copolymer increased with increasing carbonate content in the copolymer. Moreover, the protecting benzylidene groups in the copolymer poly(L ‐lactide‐co‐9‐phenyl‐2,4,8,10‐tetraoxaspiro[5,5]undecan‐3‐one) were removed by hydrogenation with palladium hydroxide on activated charcoal as a catalyst to give a functional copolymer, poly(L ‐lactide‐co‐2,2‐dihydroxylmethyl‐propylene carbonate), containing pendant primary hydroxyl groups. Complete deprotection was confirmed by 1H NMR and FTIR spectroscopy. The in vitro degradation rate of the deprotected copolymers was faster than that of the protected copolymers in the presence of proteinase K. The cell morphology and viability on a copolymer film evaluated with ECV‐304 cells showed that poly(ester carbonate)s derived from pentaerythritol are good biocompatible materials suitable for biomedical applications. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45:1737 –1745, 2007 相似文献
16.
V. A. Bershtein L. David V. M. Egorov A. M. Fainleib O. Grigorieva I. Bey P. N. Yakushev 《Journal of Polymer Science.Polymer Physics》2005,43(22):3261-3272
The nanostructure and dynamics over the temperature range of ?140 to 300 °C were studied in a series of polycyanurate (PCN)–poly(tetramethylene glycol) (PTMG) hybrid networks by wide‐angle X‐ray diffraction and small‐angle X‐ray scattering, with a synchrotron radiation setup, and by differential scanning calorimetry (DSC) and laser‐interferometric creep rate spectroscopy (CRS) techniques, respectively. The networks were synthesized from the dicyanate ester of bisphenol A and hydroxyl‐terminated PTMG with a number‐average molecular weight of 1.000 g/mol; the PTMG content varied from 0 to 40 wt %, and the degree of its chemical incorporation into the PCN network changed from 78.8 to 97%. The noncrystalline structure and considerable structural nanoheterogeneity of the hybrid networks were shown. CRS/DSC analysis revealed a complicated dynamic behavior, that is, a wide dispersion of glass transitions in the hybrid networks due to the presence of nanodomains with different degrees of rigid crosslinking (i.e., compositional nanoheterogeneity). Besides the physical significance, the plurality of glass transitions found in the PCN–PTMG hybrid networks was also of practical interest because it resulted in increasing mechanical strength of the brittle PCN network due to microplasticity arising at room temperature and moderate temperatures and the retention of some rigidity and creep resistance at temperatures much higher than the basic glass‐transition temperature. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3261–3272, 2005 相似文献
17.
Aslihan Sezgin Ümit Akbey Robert Graf Ayhan Bozkurt Abdülhadi Baykal 《Journal of Polymer Science.Polymer Physics》2009,47(13):1267-1274
In this work, poly(4‐vinylbenzylboronic acid‐co‐4(5)‐vinylimidazole) (poly(4‐VBBA‐co‐4‐Vim)) copolymers were synthesized by free‐radical copolymerization of the monomers 4‐VBBA and 4‐Vim at various monomer feed ratios. The copolymers were characterized by 1H MAS NMR and 11B MQ‐MAS NMR methods and the copolymer composition was determined via elemental analysis. The membrane properties of these copolymers were investigated after doping with phosphoric acid at several stoichiometric ratios. The proton exchange reaction between acid and heterocycle is confirmed by FTIR. Thermal properties of the samples were investigated via thermogravimetric analysis (TGA) and Differential scanning calorimetry (DSC). The morphology of the copolymers was characterized by x‐ray diffraction, XRD. The temperature dependence of proton conductivities of the samples was investigated by means of impedance spectroscopy. Proton conductivity of the copolymers increased with the doping ratio and reached to 0.0027 S/cm for poly(4‐VBBA‐co‐4‐Vim)/2H3PO4 in the anhydrous state. The boron coordination in the copolymer was determined by 11B MQ‐MAS experiment and the coexistence of three and four coordinated boron sites was observed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1267–1274, 2009 相似文献
18.
Synthesis and thermal transition behavior of model thermoplastic polyurethanes containing MDI/butanediol‐based monodisperse hard segments
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Li Ren Nam‐Goo Kang Priyank N. Shah Rudolf Faust 《Journal of polymer science. Part A, Polymer chemistry》2016,54(19):3171-3181
Amine‐terminated monodisperse hard segments (MDHSs) containing two to four 4,4′‐methylenebis (phenyl isocyanate) extended by 1,4‐butanediol have been synthesized using carboxybenzyl protecting‐deprotecting strategy. Pure MDHSs in large scale were obtained in good yield and their structures were confirmed by 1H‐, 13C‐NMR spectroscopy and GPC‐MALLS. Differential scanning calorimetry (DSC) showed that as the hard segment (HS) size increased, the melting and glass transition temperature and the change of heat capacity at glass transition of ethyl capped MDHSs increased. Model thermoplastic polyurethanes (TPUs) were synthesized using the reaction of bischloroformate of poly (tetramethylene oxide) (PTMO) diol or polyisobutylene (PIB) diol with amine‐terminated MDHSs. X‐ray diffraction results indicated the amorphous structure of model TPUs. DSC revealed HS related endotherms, regardless of SS, which were attributed to the local ordering of the HSs. Additional endotherms in PTMO based model TPUs might arise from the dissociation of hydrogen bonding between PTMO and HSs. The lower Tg in model TPUs compared to the polydisperse analogues observed by dynamic mechanical analysis (DMA) indicated higher microphase separation of monodisperse HSs. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3171–3181 相似文献
19.
Xiangchun Yin Harald D. H. Stver 《Journal of polymer science. Part A, Polymer chemistry》2005,43(8):1641-1648
Poly(N,N‐dimethylacrylamide‐co‐allyl methacrylate) (DMA‐co‐AMA) copolymers were prepared by the copolymerization of N,N‐dimethylacrylamide with allyl methacrylate (AMA). The methacryloyl group of AMA reacted preferentially, and this resulted in pendant allyl groups along the copolymer chains. Aqueous solutions of these DMA‐co‐AMA copolymers were thermoresponsive and showed liquid–liquid phase transitions at temperatures that depended on the AMA content. Hydrogel microspheres were prepared from these thermally phase‐separated liquid microdroplets by the free‐radical crosslinking of the pendant allyl groups. The morphologies of the resulting thermoresponsive microspheres as a function of the reaction temperature and the amount of the initiator were examined. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1641–1648, 2005 相似文献
20.
Na Young Kwon Geun Seok Jang Ji Hye Son Minjung Lee Hye‐Jin Cho Hee‐Seok Kweon Taek Seung Lee 《Journal of polymer science. Part A, Polymer chemistry》2011,49(1):138-146
Anionically charged fluorescent conjugated polyelectrolytes of poly{[4,7‐(2,1,3‐benzothiadiazole)‐alt‐1,4‐phenylene]‐co‐[2,5‐bis(4‐sulfonatobutoxy)‐alt‐1,4‐phenylene]} ( P1 ) and poly{[4,7‐(bis(thiophen‐2‐yl)benzo‐2,1,3‐thiadiazole)‐alt‐1,4‐phenylene]‐co‐[2,5‐bis(4‐sulfonatobutoxy)‐alt‐1,4‐phenylene]} ( P2 ) were synthesized by Suzuki crosscoupling polymerization in the presence of a palladium catalyst. The conjugated polyelectrolytes with sulfonate groups, as efficient signal amplifying reporters, were carefully designed to be soluble in water over the entire pH range examined and interact with proteins through intermolecular forces. The polymers exhibited blue emission in aqueous solutions but green or red emission in solid form depending on the conjugation length due to intermolecular exciton migration. The anionic conjugated polymers exhibited blue‐to‐green or blue‐to‐red changes in fluorescence upon exposure to charged proteins, indicating that the polymers have potential applications in fluorescent array systems for protein. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献