111 resultados para SYNDIOSPECIFIC LIVING POLYMERIZATION


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

High molecular weight semi crystalline thermoplastic poly(ester urethanes), TPEUs, were prepared from a vegetable oil-based diisocyanate, aliphatic diol chain extenders and poly(ethylene adipate) macro diol using one-shot, pre-polymer and multi-stage polyaddition methods. The optimized polymerization reaction achieved ultra-high molecular weight TPEUs (>2 million as determined by GPC) in a short time, indicating a very high HPMDI diol reactivity. TPEUs with very well controlled hard segment (HS) and soft segment (SS) blocks were prepared and characterized with DSC, TGA, tensile analysis, and WAXD in order to reveal structure property relationships. A confinement effect that imparts elastomeric properties to otherwise thermoplastic TPEUs was revealed. The confinement extent was found to vary predictably with structure indicating that one can custom engineer tougher polyurethane elastomers by "tuning" soft segment crystallinity with suitable HS block structure. Generally, the HPMDI-based TPEUs exhibited thermal stability and mechanical properties comparable to entirely petroleum-based TPEUs. (C) 2014 Elsevier Ltd. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The position of 125 countries is studied on the basis of a collection of 26 basic, health, economic and educational indicators. Multivariate statistical methods were used, including Cluster Analysis, Principal Component Analysis and Multivariate Analysis of Variance. The most discriminating variables were life expectancy the child mortality rate, the mortality rate of children of less than five years of age, the birth and fertility rates and the high-school female matriculation rate. The first principal component was interpreted as a measure of the living standard which made it possible to place the countries in order. Five clusters of countries are suggested.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Verify factors that influence the oral health status of people living with HIV/AIDS (PLWHA) in Brazil. The study was cross-sectional and includes 177 HIV-positive individuals, who answered questionnaire on the sociodemographic conditions, HIV aspects, habits, and satisfaction with the service. The oral health data were collected by means of the decayed, missing, and filled teeth (DMFT) index, use and need of dentures, and the Community Periodontal Index. Average number of the DMFT was 17.64. Most HIV-positive patients presented good periodontal status, 35.0% used dentures, 41.5% needed denture in the maxilla, and 62.0% in the mandible. In the multivariate analysis, older age and dissatisfaction with health care were associated with nonuse of dentures. The abandonment of the use of antiretroviral therapy increased the risk of PLWHA presenting more than three decayed teeth. Poor oral health of the PLWHA was mainly influenced by sociodemographic factors and use and satisfaction with service.