Investigations on the distribution of polymer additives in polypropylene using confocal fluorescence microscopy

Maringer, Leila; Grabmann, Michael K.; Muik, Martin; Nitsche, David; Romanin, Christoph; Wallner, Gernot M.; Buchberger, Wolfgang

doi:10.1080/1023666x.2017.1367120

Cited by 12 publications

(12 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Interestingly, for all PP‐R grades, the total deterioration of nonoxidized antioxidants was obtained at the same aging time independent on the comonomer type and morphological structure well before the end of the induction period characterized by full embrittlement. As pointed out by Maringer et al . for PP, polymer additives are preferentially located at the interface of spherulites.…”

Section: Resultsmentioning

confidence: 77%

Hot air aging behavior of polypropylene random copolymers

Grabmann

Wallner

Maringer

et al. 2018

J of Applied Polymer Sci

Self Cite

View full text Add to dashboard Cite

This article deals with the global aging behavior of three polypropylene random copolymer (PP-R) materials with varying primary structure and morphology. Hot air aging experiments at elevated temperatures from 95 to 135 C were carried out using micro-sized specimens with a thickness of 100 μm. Technological and analytical aging indicators were monitored for an exposure time of up to 750 days. Independent of comonomer type (ethylene vs. butylene) and morphology (α vs. β crystal form) a critical molar mass of 300 kg mol −1 was obtained. The consumption of antioxidants was slower for the β-nucleated PP-R grade with finer spherulitic structure. The β-grade outperformed the α-crystal PP-R grades resulting in about 20% higher time-to-embrittlement values.

show abstract

Section: Resultsmentioning

confidence: 77%

Hot air aging behavior of polypropylene random copolymers

Grabmann

Wallner

Maringer

et al. 2018

J of Applied Polymer Sci

Self Cite

View full text Add to dashboard Cite

show abstract

“…While there may be numerous reasons for different stabilizer systems to cause alterations in the shape of the MMD upon material global aging (i.e., various degrees of MMD broadening and multimodality), an important aspect to consider is that aging in semi-crystalline polymers is believed to occur predominantly in the amorphous regimes between spherulites and crystal lamellae [12,43]. These regimes, however, represent also the areas, where stabilizers are preferentially situated and where environmental liquids such as chlorinated water penetrate into the polymer [12,43]. Taken together, these three aspects also explain why and, to some degree, how the aging kinetics is influenced by the presence of stabilizers and the type and concentration of stabilizer systems used.…”

Section: Discussionmentioning

confidence: 99%

“…In this context, it is important to recognize that the applicability and effectivity of stabilizer systems not only depend on the environmental conditions but also on the molecular and morphological nature of the polymeric base material. Considering this complexity and the necessity for a manageable methodological approach to cover aspects of global and local aging, it is not surprising that only a limited amount of investigations exists on the effects of various stabilizer systems on the global and local aging behavior in polypropylene [4,5,6,7,12,13,14,15,16,17,19,20,39,40,41,42,43]. Nevertheless, regarding the methodological approach, novel test methods have been implemented in the laboratory of the Institute of Polymeric Materials and Testing at the Johannes Kepler University Linz to investigate such phenomena of pure environmental global aging (without stresses) and superimposed mechanical-environmental local aging in an efficient manner [4,5,6,7,12,13,14,15,17,20,40,42].…”

Section: Introductionmentioning

confidence: 99%

Global and Local Aging in Differently Stabilized Polypropylenes Exposed to Hot Chlorinated Water with and without Superimposed Mechanical-Environmental Loads

et al. 2019

Self Cite

View full text Add to dashboard Cite

The influence of chlorinated water on the global and local aging behavior of polypropylene (PP) was investigated for three differently stabilized PP grades consisting of the same PP base polymer. While one of the PP grades contained only a processing stabilizer (PP-S0), the other two were modified with a primary phenolic antioxidant (PP-S1) and a combination of a primary phenolic antioxidant and a hindered amine stabilizer (PP-S3). To study global aging effects, micro-sized specimens were pre-exposed to chlorinated water (5 mg/L free chlorine) at 60 °C for up to 750 h. Over the entire exposure period, significant material aging was detected by monitoring a continuous decrease in stabilizer content, oxidation induction temperature, mean molar mass, and mechanical strain at break. In terms of aging resistance and ultimate mechanical performance, PP-S1 was found to outperform the other two material formulations under these test conditions. Moreover, superimposed mechanical-environmental fatigue tests with cracked round bar specimens were carried out with the three PP grades in non-chlorinated (0 mg/L free chlorine) and chlorinated (5 mg/L free chlorine) water at 80 °C and 95 °C to study local crack tip aging effects. While the fatigue crack growth resistance substantially deteriorated for all three materials in chlorinated water, a significantly stronger effect was found for the higher temperature, with crack growth rates at a given stress intensity factor range in chlorinated water being ca. 30 to 50 times faster than in non-chlorinated water, depending on the material. Molar mass measurements of material samples taken from various positions of the tested CRB specimens provided clear evidence of enhanced local crack tip aging due to the chlorinated water environment.

show abstract

“…[ 143 ] PPs spherulitic structure impacts the distribution of stabilizers and antioxidants (Figure 11). [ 141,143 ] Smaller spherulites allow a uniform distribution of stabilizers throughout the polymer matrix, improving radical capture reactions and thus efficacy. [ 141,143 ] Taniike et al.…”

Section: Mechanical Recycling Of Polyolefinsmentioning

confidence: 99%

Mechanical Recycling of Packaging Plastics: A Review

Schyns

Shaver

2020

Macromol. Rapid Commun.

877

692

View full text Add to dashboard Cite

The current global plastics economy is highly linear, with the exceptional performance and low carbon footprint of polymeric materials at odds with dramatic increases in plastic waste. Transitioning to a circular economy that retains plastic in its highest value condition is essential to reduce environmental impacts, promoting reduction, reuse, and recycling. Mechanical recycling is an essential tool in an environmentally and economically sustainable economy of plastics, but current mechanical recycling processes are limited by cost, degradation of mechanical properties, and inconsistent quality products. This review covers the current methods and challenges for the mechanical recycling of the five main packaging plastics: poly(ethylene terephthalate), polyethylene, polypropylene, polystyrene, and poly(vinyl chloride) through the lens of a circular economy. Their reprocessing induced degradation mechanisms are introduced and strategies to improve their recycling are discussed. Additionally, this review briefly examines approaches to improve polymer blending in mixed plastic waste streams and applications of lower quality recyclate.

show abstract

Investigations on the distribution of polymer additives in polypropylene using confocal fluorescence microscopy

Cited by 12 publications

References 17 publications

Hot air aging behavior of polypropylene random copolymers

Hot air aging behavior of polypropylene random copolymers

Global and Local Aging in Differently Stabilized Polypropylenes Exposed to Hot Chlorinated Water with and without Superimposed Mechanical-Environmental Loads

Mechanical Recycling of Packaging Plastics: A Review

Contact Info

Product

Resources

About