Preparation and characterization of compression-molded green composite sheets made of poly(3-hydroxybutyrate) reinforced with long pita fibers

[EN] Novel green composites were successfully prepared from bacterial poly(3-hydroxybutyrate) (PHB) and pita fibers derived from the agave plant (Agave americana). Various weight contents (10, 20, 30, and 40 wt.-%) of pita fibers at different lengths (5, 15, and 20 mm) were successfully incorporated into PHB by compression molding. The newly prepared PHB/pita fibers composite sheets were characterized in terms of their mechanical and thermomechanical properties and then related to their morphology after fracture. Attained results indicated that the mechanical stiffness of PHB significantly improved with both the content and length of pita fibers, although ductile properties were reduced. In particular, the elastic modulus of the 40 wt.-% PHB composite sheets containing 20-mm-long pita fibers was approximately 55% higher than the unfilled PHB sheet. Shore D hardness also improved, achieving the shortest pita fibers the highest improvement. Pita fibers with lengths of 15 and 20 mm also increased the Vicat softening point and heat deflection temperature (HDT) by 38 and 21°C, respectively. Due to their optimal shape, it is concluded that pita fibers with lengths above 15 mm can potentially reinforce and improve the performance of PHB biopolymer. In addition, the compression-molding methodology described in this research work represents a cost-effective pathway to feasibly prepare long-fiber- reinforced thermoplastics (LFRTs) fully based on renewable raw materials. Resultant green composite sheets can be of interest for the development of sustainable parts in the automotive industry and other advanced applications in polymer technology.This research was supported by the Spanish Ministry of Economy and Competitiveness (project MAT2014-59242- C2-1-R). The authors also thank “Conselleria d’Educació, Cultura i Esport—Generalitat Valenciana” (grant number GV/2014/008) for financial support.Torres-Giner, S.; Montanes, N.; Fombuena, V.; Boronat, T.; Sanchez-Nacher, L. (2016). Preparation and characterization of compression-molded green composite sheets made of poly(3-hydroxybutyrate) reinforced with long pita fibers. Advances in Polymer Technology. 1-11. https://doi.org/10.1002/adv.21789S11

Factors associated with the utilization of the community support systems against violence among the married women living with HIV attending the antiretroviral therapy clinic at Kabale regional referral hospital in Southwestern Uganda (n = 424, April 2021).

Factors associated with the utilization of the community support systems against violence among the married women living with HIV attending the antiretroviral therapy clinic at Kabale regional referral hospital in Southwestern Uganda (n = 424, April 2021).</p

Socio-demographic characteristics of the married women living with HIV attending antiretroviral therapy clinic at Kabale regional referral hospital in southwestern Uganda (n = 424, April, 2021).

Socio-demographic characteristics of the married women living with HIV attending antiretroviral therapy clinic at Kabale regional referral hospital in southwestern Uganda (n = 424, April, 2021).</p

Predictors for the utilization of CoSaV amongst the married women living with HIV attending the antiretroviral therapy clinic at Kabale regional referral hospital in Southwestern Uganda (n = 424, April 2021).

Predictors for the utilization of CoSaV amongst the married women living with HIV attending the antiretroviral therapy clinic at Kabale regional referral hospital in Southwestern Uganda (n = 424, April 2021).</p

Machining Behavior of Natural Fiber Composites

The machinability of thermoplastic natural fiber composites is investigated in this article. An exploratory study is performed to investigate the effect of natural fiber type, fiber reinforcement structure, tool geometry, and process parameters on the cutting behavior of natural fibers under the usual machining processes. Results show how the cutting behavior if natural fiber is significantly sensitive to the variation of the different studied parameters. The article is concluded by technical recommendations to improve the machinability of natural fiber composites