Made available in DSpace on 2014-12-17T14:06:57Z (GMT). No. of bitstreams: 1
AntonioMM_DISSERT.pdf: 3167534 bytes, checksum: a8247e394e6c3656375c3f16b429e065 (MD5)
Previous issue date: 2010-10-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Poly(methyl methacrylate)/clay nanocomposites were prepared by melt mixing using a
montmorillonite-rich clay (MMT). The clay in natura was treated with acrylic acid to
facilitate the dispersion in the polymer matrix. A masterbatch of PMMA/clay was prepared
and combined with the pure PMMA and then subjected to extrusion process using singlescrew
and twin-screw extruders followed by injection. Nanocomposites were processed with
clay contents of 1, 3, 5 and 8 wt.%. The effect of shear processing on the morphology of the
nanocomposites was evaluated by XRD, SEM and TEM. Thermal and mechanical properties
of the nanocomposites were investigated through TGA, DSC, HDT, VICAT, tensile and
impact tests, to evaluate the effect of the addition of clay to the PMMA matrix. Flammability
tests were also conducted to investigate the effect of the addition of clay on the flame
retardation properties. SEM images of the nanocomposites indicated the presence of clay
agglomerates, which resulted in the reduction of properties such as thermal stability,
mechanical strength and impact resistance, and increased the rate of burning for materials
processed by both extrusion routes / Nanocomp?sitos de poli(metacrilato de metila) (PMMA) foram preparados a partir da
t?cnica de mistura no estado fundido com argila rica em montmorilonita (MMT). A argila in
natura foi inicialmente tratada com ?cido acr?lico para facilitar a dispers?o na matriz
polim?rica. Depois, foi preparado um concentrado de PMMA e argila que foi combinado com
o PMMA puro e submetido ao processo de extrus?o realizado em extrusoras monorosca e
dupla rosca com posterior inje??o. Nanocomp?sitos foram processados com 1, 3, 5 e 8% em
massa de argila. O efeito do cisalhamento sobre a morfologia dos nanocomp?sitos foi
avaliado por DRX, MEV e MET. Para avaliar o efeito da adi??o de argila na matriz de
PMMA foram investigadas propriedades t?rmicas e mec?nicas, atrav?s de an?lises de TG,
DSC, HDT, VICAT, tra??o e impacto. Ensaios de inflamabilidade foram tamb?m realizados
para investigar o efeito da adi??o de argila sobre as propriedades de retardo de chama. As
an?lises morfol?gicas mostraram a presen?a de aglomerados de argila distribu?dos na matriz
de PMMA, o que resultou na redu??o de propriedades como estabilidade t?rmica, resist?ncia
mec?nica e ao impacto, e elevou a taxa de queima para os materiais processados por ambas as
rotas de extrus?o
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/12710 |
| Date | 15 October 2010 |
| Creators | Medeiros, Antonio Marcos de |
| Contributors | CPF:40405036191, http://lattes.cnpq.br/7249500407405478, Nascimento, Maria Carolina Burgos Costa do, CPF:03449466496, http://lattes.cnpq.br/4409025248163428, Ara?jo, Edcleide Maria, CPF:78927560434, http://lattes.cnpq.br/1097999681102529, Melo, Jos? Daniel Diniz, Ito, Edson Noriyuki |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Ci?ncia e Engenharia de Materiais, UFRN, BR, Processamento de Materiais a partir do P?; Pol?meros e Comp?sitos; Processamento de Materiais a part |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
Page generated in 0.0454 seconds