scholarly journals Evaluation of Degradable Spun-Melt 100% Polylactic Acid Nonwoven Mulch Materials in a Greenhouse Environment

2013 ◽  
Vol 8 (4) ◽  
pp. 155892501300800 ◽  
Author(s):  
Larry C. Wadsworth ◽  
Douglas G. Hayes ◽  
Annette L. Wszelaki ◽  
Tommy L. Washington ◽  
Jeffrey Martin ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Mechanical Strength ◽  
Polylactic Acid ◽  
Poly Lactic Acid ◽  
High Mechanical Strength ◽  
Biobased Polymers ◽  
Agricultural Mulches ◽  
Complete Mineralization

The tendency of most commercially available plastic agricultural mulches to undergo only partial fragmentation with time leads to their long-term persistence in soil, resulting in potentially detrimental environmental hazards. Nonwovens composed of biobased polymers such as poly(lactic acid) (PLA) with micron-sized fibers may be potentially valuable for agricultural mulches due to their high mechanical strength and potential ability to undergo complete mineralization. To assess the performance of 100% PLA spunbond (SB) and meltblown (MB) mulches, and commercially available cellulosic mulch, a greenhouse bench study was conducted where the mulches were buried in soil augmented with either lime or compost for 10 and 29 wk to accelerate biodegradation and mineralization. At 10 and 29 wk, MB and SB mulches, respectively, lost considerable mechanical strength for all soil treatments while showing only minimal signs of loss in molecular weight.

scholarly journals Poly(lactic Acid): A Versatile Biobased Polymer for the Future with Multifunctional Properties—From Monomer Synthesis, Polymerization Techniques and Molecular Weight Increase to PLA Applications

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1822
Author(s):  
Evangelia Balla ◽  
Vasileios Daniilidis ◽  
Georgia Karlioti ◽  
Theocharis Kalamas ◽  
Myrika Stefanidou ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Chain Extension ◽  
Poly Lactic Acid ◽  
Plastic Pollution ◽  
Practical Applications ◽  
Decomposition Reactions ◽  
Melt Polycondensation ◽  
Polymerization Conditions ◽  
Molecular Weight Increase

Environmental problems, such as global warming and plastic pollution have forced researchers to investigate alternatives for conventional plastics. Poly(lactic acid) (PLA), one of the well-known eco-friendly biodegradables and biobased polyesters, has been studied extensively and is considered to be a promising substitute to petroleum-based polymers. This review gives an inclusive overview of the current research of lactic acid and lactide dimer techniques along with the production of PLA from its monomers. Melt polycondensation as well as ring opening polymerization techniques are discussed, and the effect of various catalysts and polymerization conditions is thoroughly presented. Reaction mechanisms are also reviewed. However, due to the competitive decomposition reactions, in the most cases low or medium molecular weight (MW) of PLA, not exceeding 20,000–50,000 g/mol, are prepared. For this reason, additional procedures such as solid state polycondensation (SSP) and chain extension (CE) reaching MW ranging from 80,000 up to 250,000 g/mol are extensively investigated here. Lastly, numerous practical applications of PLA in various fields of industry, technical challenges and limitations of PLA use as well as its future perspectives are also reported in this review.

scholarly journals High-strength and fibrous capsule–resistant zwitterionic elastomers

2021 ◽  
Vol 7 (1) ◽  
pp. eabc5442
Author(s):  
Dianyu Dong ◽  
Caroline Tsao ◽  
Hsiang-Chieh Hung ◽  
Fanglian Yao ◽  
Chenjue Tang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Strength ◽  
High Strength ◽  
Design Principles ◽  
Fibrous Capsule ◽  
High Mechanical Strength ◽  
Capsule Formation ◽  
Locking Mechanism ◽  
Fibrous Capsule Formation

The high mechanical strength and long-term resistance to the fibrous capsule formation are two major challenges for implantable materials. Unfortunately, these two distinct properties do not come together and instead compromise each other. Here, we report a unique class of materials by integrating two weak zwitterionic hydrogels into an elastomer-like high-strength pure zwitterionic hydrogel via a “swelling” and “locking” mechanism. These zwitterionic-elastomeric-networked (ZEN) hydrogels are further shown to efficaciously resist the fibrous capsule formation upon implantation in mice for up to 1 year. Such materials with both high mechanical properties and long-term fibrous capsule resistance have never been achieved before. This work not only demonstrates a class of durable and fibrous capsule–resistant materials but also provides design principles for zwitterionic elastomeric hydrogels.

Engineering microenvironment of biodegradable polyester systems for drug stability and release control

2021 ◽  
Author(s):  
Nisar Ul Khaliq ◽  
Dhawal Chobisa ◽  
Coralie A Richard ◽  
Monica R Swinney ◽  
Yoon Yeo
Keyword(s):  
Lactic Acid ◽  
Glycolic Acid ◽  
Release Kinetics ◽  
Drug Stability ◽  
Poly Lactic Acid ◽  
Polymeric Systems ◽  
Us Fda ◽  
History Of Use ◽  
Release Control

Polymeric systems made of poly(lactic acid) or poly(lactic-co-glycolic acid) are widely used for long-term delivery of small and large molecules. The advantages of poly(lactic acid)/poly(lactic-co-glycolic acid) systems include biodegradability, safety and a long history of use in US FDA-approved products. However, as drugs delivered by the polymeric systems and their applications become more diverse, the significance of microenvironment change of degrading systems on long-term drug stability and release kinetics has gained renewed attention. In this review, we discuss various issues experienced with acidifying microenvironment of biodegradable polymer systems and approaches to overcome the detrimental effects of polymer degradation on drug stability and release control.

scholarly journals Effects of synthesised polyaniline (PAni) contents on the anti-static properties of PAni-based polylactic acid (PLA) films

RSC Advances ◽  
2020 ◽  
Vol 10 (65) ◽  
pp. 39693-39699
Author(s):  
Pei-Yi Wong ◽  
Sook-Wai Phang ◽  
Azizah Baharum
Keyword(s):  
Lactic Acid ◽  
Polymer Film ◽  
Polylactic Acid ◽  
Poly Lactic Acid ◽  
Static Properties ◽  
Biodegradable Poly

An anti-static polymer film was prepared using biodegradable poly(lactic acid) as a matrix and polyaniline (PAni) as an anti-static agent to eliminate accumulated static charges.

scholarly journals Blends of low molecular weight of poly lactic acid (PLA) with gondorukem (gum rosin)

2018 ◽  
Author(s):  
Mujtahid Kaavessina ◽  
Sperisa Distantina ◽  
Achmad Chafidz ◽  
Aditya Utama ◽  
Venisa Mega Puteri Anggraeni
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Low Molecular Weight ◽  
Gum Rosin

Study of the Properties of Plasticised Poly(Lactic Acid) with Poly(1,3-Butylene Adipate)

2008 ◽  
Vol 16 (9) ◽  
pp. 597-604 ◽  
Author(s):  
Wang Ning ◽  
Zhang Xingxiang ◽  
Yu Jiugao ◽  
Fang Jianming
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Glass Transition ◽  
Renewable Resources ◽  
Migration Rate ◽  
Poly Lactic Acid ◽  
Elongation At Break ◽  
Thermally Induced ◽  
Migration Resistance ◽  
Area Of Application

Poly(lactic acid) (PLA) is a biodegradable thermoplastic that can be produced from renewable resources, and so was considered as a major alternative to petroleum-based plastics for packaging applications. However, plasticisation of PLA was required in order to obtain films with sufficient flexibility. Poly(1, 3-butylene adipate) (PBA) was used as a novel plasticiser for PLA, and acetyltributyl citrate (ATBC) was used as the control. FTIR revealed that interaction took place between PLA and plasticiser. With an increasing plasticiser content, storage modulus and glass transition temperature decreased, but elongation at break increased. The elongation at break of PBA-plasticised PLA (PBA content 30 wt.%) could be above 600%, higher than that of ATBC-plasticised PLA (ATBC content 30 wt.%). Moreover, PBA was able to restrain thermally induced migration of plasticiser in plasticised PLA. It was also found that the migration rate of ATBC was directly proportional to the ATBC content in the blends. The rheology showed that the plasticiser could obviously decrease the shear viscosity and improve the fluidity of the blends. PBA was therefore recognised as a novel plasticiser for enhancing the properties of PLA. In particular, as a biodegradable polymer, PBA, when used as a plasticiser in PLA, can enhance migration resistance for its proper molecular weight. Moreover, the area of application of plasticised PLA is broadened.

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