Composites based on renewable materials: Polyurethane‐type matrices from forest byproduct/vegetable oil and reinforced with lignocellulosic fibers

Coir fibers were retted in distilled water (DW) and saline water (SW) for up to 12 weeks. Fibers had diameters of 0.16 mm to 0.56 mm, gauge lengths (GL) of 20 mm and 50 mm, and loaded at strain rates of 5, 20, 40, and 60 mm/min. Tensile strength, Young's modulus, and strain at break properties were evaluated and the results statistically analyzed using analysis of variance (ANOVA). For non-retted fibers, as the gauge length decreased, the tensile and strain at break increased by 14% and 42%, respectively, while the stiffness increased by 33% for larger gauge lengths. As the fiber diameter decreased, the tensile strength increased from 48.45 MPa to 134.41 MPa for 50 mm gauge length fibers. X-ray diffraction (XRD) was used to calculate the crystallinity index (CI) of the coir fibers. Secondary electron microscopy was used to assess the fiber surface and fractured area. Although the chemical composition was different, the properties of Trinidad coir fibers were in-line with coir fibers from other parts of the world making them an ideal material of choice for composites.

Section: Resultssupporting

confidence: 75%

Characterization and mechanical property of Trinidad coir fibers

Mathura

Cree

2016

“…They are considered to be one of the cheapest and most abundant biological resources and to have the advantage of inherent biodegradability and reduced toxicity. Vegetable oils are currently being used for the synthesis of both thermoplastic and thermosetting polymers . To achieve this, it is important to functionalize the triglyceride molecule.…”

Section: Introductionmentioning

confidence: 99%

Highly functional lactic acid ring‐opened soybean polyols applied to rigid polyurethane foams

Herrán

Amalvy

Chiacchiarelli

2019

We synthesized polyols with high hydroxyl functionalities (F OH s), between 9.0 and 12.6, and characterized them with differential scanning calorimetry, thermogravimetric analysis, and size exclusion chromatography after we parametrically studied the ringopening reaction of epoxidized soybean oil with lactic acid (LA) as a function of the reaction temperature and lactic acid equivalent fraction (f LA ). An increase of only 20 C in the reaction temperature (from 80 to 100 C) caused changes in the hydroxyl number (+17.8%), F OH (-25%), viscosity (-14.0%), and oligomeric content (-24.1%). f LA mostly affected the ring-opening yield, and only for f LA values above 0.4 was possible to achieve values higher than 80%. Rigid polyurethane foams (rPUFs) were synthesized and characterized with scanning electron microscopy, dynamic mechanical analysis (DMA), and compressive mechanical tests. rPUFs with a very high specific compressive strength (7.8 kPa kg -1 m 3 ) were synthesized solely with biobased soybean oil. DMA revealed a compromised relationship between the specific compressive strength and its temperature dependence. To increase the first one, the most relevant method was to increase F OH . Instead, to increase the latter one, the OH number had to be maximized.

“…These materials are carbon‐neutral, which has a significantly positive impact on the atmospheric greenhouse effect and global warming . Thus, the use of bio‐based composite materials, such as polymeric composites reinforced by natural fibers, has emerged as one of the solutions to these complex environmental and sustainability problems …”

Section: Introductionmentioning

confidence: 99%

Processing and thermal properties of composites based on recycled PET, sisal fibers, and renewable plasticizers

Santos

Castro

Rúvolo-Filho

et al. 2014

Self Cite

This investigation focuses on the preparation of bio‐based composites from recycled poly (ethylene terephthalate) (PET) and sisal fibers (3 cm, 15 wt %), via thermopressing process. Plasticizers derived from renewable raw materials are used, namely, glycerol, tributyl citrate (TBC) and castor oil (CO), to decrease the melting point of the recycled PET (Tm ∼ 265°C), which is sufficiently high to initiate the thermal decomposition of the lignocellulosic fiber. All used materials are characterized by thermogravimetric analysis and differential scanning calorimetry, and the composites are also characterized via dynamic mechanical thermal analysis. The storage modulus (30°C) and the tan δ peak values of CT [PET/sisal/TBC] indicate that TBC also acts as a compatibilizing agent at the interface fiber/PET, as well as a plasticizer. To compare different processing methods, rheometry/thermopressing and compression molding are used to prepare the recycled PET/sisal/glycerol/CO composites. These two different methods of processing show no significant influence on the thermal properties of these composites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40386.