Relationships between synthesis and mechanical properties of new polyurea materials

Samson, Nathalie; Méchin, Françoise; Pascault, Jean‐Pierre

doi:10.1002/(sici)1097-4628(19970919)65:12<2265::aid-app2>3.0.co;2-7

Cited by 22 publications

(16 citation statements)

References 6 publications

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“…Thermodynamic incompatibility results in a phase‐separated microstructure of hard and soft domains. Polyurea is a versatile material and a wide variety of microstructures/properties can be obtained depending on the chemical content,1–4 molecular dispersion,5, 6 symmetry,7, 8 polarity,9, 10 processing,11, 12 synthesis,13 and added filling particles 14, 15. Moreover, the domains are not rigorously constituted of only their respective segments: the hard domains may contain regions of occluded soft domains, whereas the soft domains may contain isolated hard segments,16 which act more like crosslinks rather than a separate phase 9.…”

Section: Introductionmentioning

confidence: 99%

Impact of the diagnostic label of osteoarthritis on perceptions of disability and willingness to help a parent in African Americans and whites

Mingo¹,

McIlvane²,

Haley³

2006

Arthritis & Rheumatism

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Objective. Family members are central to arthritis care, but little is known about public perceptions of osteoarthritis (OA) and how cultural diversity affects these perceptions. We examined the effects of participant race and diagnostic label of OA on family members' perceptions and willingness to help a parent with OA. Methods. A total of 105 young adult African American and 308 young adult white participants were randomly assigned to read 1 of 2 vignettes (OA label versus no label) describing an older mother with marked pain and disability. Effects for race and diagnostic label were examined. Results. Participants who were told that the mother had OA were more likely to believe the mother's problems were due to illness, but were less likely to believe that better health care would improve her condition than participants not told a diagnosis. African Americans attributed less blame to the mother, showed less anger, more sympathy, and were more willing to help compared with whites. Conclusion. The finding that the OA label leads to pessimism concerning the benefits of health care for a parent suggests a need for public education on the effectiveness of arthritis care. Race differences in perceptions of the parent and willingness to provide care are consistent with previous literature on race and family caregiving, and indicate that cultural values regarding family caregiving may be important in arthritis care. Family members could serve as important allies for elderly individuals with OA, and public health efforts should not just target older adults but should also provide information on arthritis care for families.

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Section: Introductionmentioning

confidence: 99%

Impact of the diagnostic label of osteoarthritis on perceptions of disability and willingness to help a parent in African Americans and whites

Mingo¹,

McIlvane²,

Haley³

2006

Arthritis & Rheumatism

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“…Polyaddition reactions of four different diisocyanates, including TDI, 4,4′‐diphenylmethane diisocyanate (MDI), IPDI, and NDI, in dry NMP with the DA afforded the polyureas. As mentioned previously, the reaction of DA with diisocyanate is the best method for preparing polyureas because of the low‐temperature polymerization reaction and the lack of byproducts 5–13…”

Section: Resultsmentioning

confidence: 98%

“…DAs are regularly used to cure diisocyanates, especially isocyanate prepolymers, to give polyureas; this is a step‐growth addition reaction of amine across the carbon‐nitrogen double bond 5–13. The main advantages of this method are that polymerization can occur at a low temperature and that no byproducts are produced.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of novel pyridine‐based polyureas with enhanced solubility and high thermal stability

Ehsani

Mehdipour‐Ataei

Mahmoodi

2012

J of Applied Polymer Sci

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The main aim of this study was the preparation of modified polyureas with improved thermal stability and solubility. Accordingly, a series of aromatic/aliphatic pyridine-based polyureas was synthesized from the reaction of a novel diamine (DA) with different diisocyanates, including 4,4 0 -diphenylmethane diisocyanate, toluene diisocyanate, 1,5-naphthalene diisocyanate, and isophorone diisocyanate, by a solution polymerization route. The DA monomer was prepared via a two-step reaction. The nucleophilic substitution reaction of oxydianiline with 6-chloronicotinoylchloride led to the preparation of a diamide dichloro compound, and the subsequent reaction of this compound with 4-aminophenol resulted in the preparation of the DA. After polymerization, the structural characterization and physical properties of the polymers were examined. The resulting polymers were soluble in common polar aprotic solvents, and they showed improved thermal stabilities in comparison with common polyureas. V C 2012 Wiley Periodicals, Inc. J Appl Polym Sci 126: 608-613, 2012

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“…Thus, the behavior of these materials can be controlled by the synthesis parameters. A such parameter is represented by the addition of chain extenders, like, for example, 3,3′‐dichloro‐4,4′‐diamino‐diphenylmethane, 3,5‐diethyltoluene‐2,4‐diamine, m ‐phenylene diamine, di(methylthio) toluene diamine, 4,4′‐methylenebis(2,6‐diethylaniline), 4,4′‐methylenebis(cyclohexyl amine), 4,4′‐methylenebis(2‐methyl cyclo‐hexylamine), 4,4′‐methylenebis(2‐methyl 6‐ethyl cyclo‐hexyl amine), which have already been mentioned in previous studies …”

Section: Introductionmentioning

confidence: 99%

Novel polyurea polymers with enhanced mechanical properties

Toader

Rusen

Teodorescu

et al. 2016

J of Applied Polymer Sci

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The present work describes the preparation of a set of new polyurea polymers suitable for ballistic protection applications by employing different aromatic diamines derivatives with different flexibility degrees. This modification would allow the synthesis of polymers with both enhanced and controllable mechanical properties through the combination of aliphatic and aromatic molecules. Besides the classical methylene diphenyl diisocyanate and polypropylene glycol bis(2-aminopropyl ether) (PPG), benzidine, 4,4 0diaminodiphenylmethane and 3,6-diamino carbazole were chosen as the third monomer and used in different ratios toward PPG, in order to optimize the polymer properties. The proportions between the polyurea components were selected as such to achieve the total consumption of the monomers. The different types of polyurea obtained have been characterized by Fourier transform infrared spectroscopy, thermal measurements (differential scanning calorimetry and thermogravimetric analysis), tensile tests, and scanning electron microscope.

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Relationships between synthesis and mechanical properties of new polyurea materials

Cited by 22 publications

References 6 publications

Impact of the diagnostic label of osteoarthritis on perceptions of disability and willingness to help a parent in African Americans and whites

Impact of the diagnostic label of osteoarthritis on perceptions of disability and willingness to help a parent in African Americans and whites

Synthesis and characterization of novel pyridine‐based polyureas with enhanced solubility and high thermal stability

Novel polyurea polymers with enhanced mechanical properties

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