The thermal‐mechanical degradation of mineral‐filled polypropylene‐ethylene copolymer composites during extrusion process

2020 ◽  
Author(s):  
Lip Teng Saw ◽  
Firuz Zainuddin ◽  
Xuan Viet Cao ◽  
Du Ngoc Uy Lan
Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 58 ◽  
Author(s):  
Jamileh Shojaeiarani ◽  
Dilpreet S. Bajwa ◽  
Chad Rehovsky ◽  
Sreekala G. Bajwa ◽  
Ghazal Vahidi

Biopolymers are an emerging class of materials being widely pursued due to their ability to degrade in short periods of time. Understanding and evaluating the recyclability of biopolymers is paramount for their sustainable and efficient use in a cost-effective manner. Recycling has proven to be an important solution, to control environmental and waste management issues. This paper presents the first recycling assessment of Solanyl, Bioflex, polylactic acid (PLA) and PHBV using a melt extrusion process. All biopolymers were subjected to five reprocessing cycles. The thermal and mechanical properties of the biopolymers were investigated by GPC, TGA, DSC, mechanical test, and DMA. The molecular weights of Bioflex and Solanyl showed no susceptible effect of the recycling process, however, a significant reduction was observed in the molecular weight of PLA and PHBV. The inherent thermo-mechanical degradation in PHBV and PLA resulted in 20% and 7% reduction in storage modulus, respectively while minimal reduction was observed in the storage modulus of Bioflex and Solanyl. As expected from the Florry-Fox equation, recycled PLA with a high reduction in molecular weight (78%) experienced 9% reduction in glass transition temperature. Bioflex and Solanyl showed 5% and 2% reduction in molecular weight and experienced only 2% reduction in glass transition temperature. These findings highlight the recyclability potential of Bioflex and Solanyl over PLA and PHBV.


Author(s):  
Michael E. Rock ◽  
Vern Kennedy ◽  
Bhaskar Deodhar ◽  
Thomas G. Stoebe

Cellophane is a composite polymer material, made up of regenerated cellulose (usually derived from wood pulp) which has been chemically transformed into "viscose", then formed into a (1 mil thickness) transparent sheet through an extrusion process. Although primarily produced for the food industry, cellophane's use as a separator material in the silver-zinc secondary battery system has proved to be another important market. We examined 14 samples from five producers of cellophane, which are being evaluated as the separator material for a silver/zinc alkaline battery system in an autonomous underwater target vehicle. Our intent was to identify structural and/or chemical differences between samples which could be related to the functional differences seen in the lifetimes of these various battery separators. The unused cellophane samples were examined by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). Cellophane samples were cross sectioned (125-150 nm) using a diamond knife on a RMC MT-6000 ultramicrotome. Sections were examined in a Philips 430-T TEM at 200 kV. Analysis included morphological characterization, and EDS (for chemical composition). EDS was performed using an EDAX windowless detector.


TAPPI Journal ◽  
2018 ◽  
Vol 17 (01) ◽  
pp. 31-37
Author(s):  
Bryan McCulloch ◽  
John Roper ◽  
Kaitlin Rosen

Barrier coatings are used in applications including food packaging, dry goods, and consumer products to prevent transport of different compounds either through or into paper and paperboard substrates. These coatings are useful in packaging to contain active ingredients, such as fragrances, or to protect contents from detrimental substances, such as oxygen, water, grease, or other chemicals of concern. They also are used to prevent visual changes or mechanical degradation that might occur if the paper becomes saturated. The performance and underlying mechanism depends on the barrier coating type and, in particular, on whether the barrier coating is designed to prevent diffusive or capillary transport. Estimates on the basis of fundamental transport phenomena and data from a broad screening of different barrier materials can be used to understand the limits of various approaches to construct barrier coatings. These estimates also can be used to create basic design rules for general classes of barrier coatings.


1973 ◽  
Vol 1 (4) ◽  
pp. 354-362 ◽  
Author(s):  
F. R. Martin ◽  
P. H. Biddison

Abstract Treads made with emulsion styrene-butadiene copolymer (SBR), solution SBR, polybutadiene (BR), and a 60/40 emulsion SBR/BR mixture were built as four-way tread sections on G78-15 belted bias tires, which were driven over both concrete and gravel-textured highways and on a small, circular, concrete test track. The tires were front mounted. When driven on concrete highway, all except the BR tread had either crumbled- or liquid-appearing surfaces, thought to have been formed by mechanical degradation or fatigue. When cornered on concrete, these materials formed small cylindrical particles or rolls. The BR tread had a smooth, granular-textured surface when driven on concrete highway and a ridge or sawtooth abrasion pattern when cornered on concrete. All the materials appeared rough and torn when run on gravel-textured highway. The differences in wear surface formed on BR tread and the other three are thought to be due primarily to the relatively high resilience of BR.


2019 ◽  
Author(s):  
Florian Strauss ◽  
Lea de Biasi ◽  
A-Young Kim ◽  
Jonas Hertle ◽  
Simon Schweidler ◽  
...  

Measures to improve the cycling performance and stability of bulk-type all-solid-state batteries (SSBs) are currently being developed with the goal of substituting conventional Li-ion battery (LIB) technology. As known from liquid electrolyte based LIBs, layered oxide cathode materials undergo volume changes upon (de)lithiation, causing mechanical degradation due to particle fracture, among others. Unlike solid electrolytes, liquid electrolytes are somewhat capable of accommodating morphological changes. In SSBs, the rigidity of the materials used typically leads to adverse contact loss at the interfaces of cathode material and solid electrolyte during cycling. Hence, designing zero- or low-strain electrode materials for application in next-generation SSBs is desirable. In the present work, we report on novel Co-rich NCMs, NCM361 (60% Co) and NCM271 (70% Co), showing minor volume changes up to 4.5 V vs Li<sup>+</sup>/Li, as determined by <i>operando</i> X-ray diffraction and pressure measurements of LIB pouch and pelletized SSB cells, respectively. Both cathode materials exhibit good cycling performance when incorporated into SSB cells using argyrodite Li<sub>6</sub>PS<sub>5</sub>Cl solid electrolyte, albeit their morphology and secondary particle size have not yet been optimized.


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