SciELO - Scientific Electronic Library Online

 
vol.28 número2Ultrasound assisted miniemulsion polymerization to prepare poly(urea-urethane) nanoparticlesThe effect of molecular weight and hydrolysis degree of poly(vinyl alcohol)(PVA) on the thermal and mechanical properties of poly(lactic acid)/PVA blends índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados

Journal

Artigo

Indicadores

Links relacionados

Compartilhar


Polímeros

versão impressa ISSN 0104-1428versão On-line ISSN 1678-5169

Resumo

JAQUES, Nichollas Guimarães et al. Effect of heat cycling on melting and crystallization of PHB/TiO2 compounds. Polímeros [online]. 2018, vol.28, n.2, pp.161-168.  Epub 21-Maio-2018. ISSN 0104-1428.  http://dx.doi.org/10.1590/0104-1428.12416.

Compounds of poly(3-hydroxybutyrate) (PHB) and titanium dioxide (TiO2) with filler content between 1% and 10% were prepared in a laboratory internal mixer. The effect of heating and cooling rates on the crystallization and melting of PHB/TiO2 compounds was investigated by differential scanning calorimetry (DSC). Melt and cold crystallization rates rise with increasing cooling/heating rates. A higher cooling rate translates to a lower melt crystallization temperature, while a higher heating rate results in a higher cold crystallization temperature. TiO2 promotes melt crystallization of PHB, behaving as a nucleant agent. The total crystallinity developed after melt and cold crystallization decreases for low levels of TiO2, i.e. 2% per weight, and is almost independent of the heating/cooling rate. The melting temperatures and rates are minimally affected by both the heating rate and filler content. The results suggest that the desired PHB microstructure can be controlled by filler content and adjusted heating/cooling rate.

Palavras-chave : crystallization; DSC; melting; PHB; titanium dioxide.

        · texto em Inglês     · Inglês ( pdf )