Structural effect of linear and star-shaped poly(L-lactic acid) on physical properties

2004 ◽  
Vol 42 (6) ◽  
pp. 939-946 ◽  
Author(s):  
Eun Sub Kim ◽  
Byoung Chul Kim ◽  
Soo Hyun Kim
Keyword(s):  
Lactic Acid ◽  
Physical Properties ◽  
Structural Effect

Synthesis and Properties of Biodegradable Liquid Crystalline Poly(ester-Urethane)s Based on Poly(L-Lactic Acid)

2013 ◽  
Vol 652-654 ◽  
pp. 459-462
Author(s):  
Ya Tong Guo ◽  
Zhu Zheng ◽  
Zhen Qi Hou ◽  
Jie Du
Keyword(s):  
Phase Transition ◽  
Thermal Stability ◽  
Lactic Acid ◽  
Physical Properties ◽  
Liquid Crystalline ◽  
Degradation Rate ◽  
Hydrolytic Degradation ◽  
Hexamethylene Diisocyanate ◽  
Solution Polymerization ◽  
Phase Transition Temperatures

A series of biodegradable segmented liquid crystalline poly(ester-urethane)s were prepared by solution polymerization of poly(L-lactic acid) (PLLA), mesogenic diol prepolymer poly(butylene terephthaloyldioxy dibenzoates) (MD), and hexamethylene diisocyanate (HDI). The MD content was varied from 0 to 40 mol% so that the effects of the mesogen content on the thermal and physical properties, and hydrolytic degradation were examined respectively. It was found that introducing mesogens units could increase the thermal stability and the elastic properties, while reduced the phase transition temperatures and the hydrolytic degradation rate.

Preparation of Poly(Lactic Acid) Acrylate for UV-Curable Coating Applications

2015 ◽  
Vol 659 ◽  
pp. 570-574 ◽  
Author(s):  
Apinya Musidang ◽  
Nantana Jiratumnukul
Keyword(s):  
Lactic Acid ◽  
Physical Properties ◽  
High Efficiency ◽  
Low Energy ◽  
Poly Lactic Acid ◽  
Coating Film ◽  
Pencil Hardness ◽  
Uv Curable ◽  
Low Energy Consumption ◽  
Volatile Organic

UV-curable process is widely used for paints, inks and adhesives due to its rapid curing, low energy consumption, high efficiency and low volatile organic compounds (VOCs). The objective of this research is to prepare poly(lactic acid) (PLA) based UV-curable coating by using glycolyzed PLA. PLA was glycolyzed by ethylene glycol (EG) at 170°C for 90 minutes. The obtained glycolyzed PLA was reacted with methacrylic anhydride (MAAH) to provide PLA acrylate oligomer. The obtained PLA acrylate oligomer was used in coating formulations with various amounts of photoinitiator and cured under UV radiation. Physical properties of cured coating film were investigated such as pencil hardness, gloss and haze. The results showed that poly(lactic acid) (PLA) based UV-curable coating provided good physical properties.

Compatibility and physical properties of poly(lactic acid)/poly(ethylene terephthalate glycol) blends

2012 ◽  
Vol 20 (12) ◽  
pp. 1300-1306 ◽  
Author(s):  
Jun Yong Park ◽  
Sung Yeon Hwang ◽  
Won Jae Yoon ◽  
Eui Sang Yoo ◽  
Seung Soon Im
Keyword(s):  
Lactic Acid ◽  
Physical Properties ◽  
Ethylene Terephthalate ◽  
Poly Lactic Acid ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

scholarly journals Effect of Lactic Acid Content into on during Miconazole Eye Drops to be Used for Infection Preventive

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yoshimura K ◽  
Inoue Y ◽  
Koizumi A ◽  
Suzuki M ◽  
Itakura S ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Physical Properties ◽  
Acid Content ◽  
Eye Drops ◽  
Lactic Acid Content ◽  
The Stability

Purpose: The aims of this study were to prepare a 0.1% Miconazole (MCZ) eye-drop solution and to evaluate the stability and physical properties of the preparation.

scholarly journals Physical Properties and Non-Isothermal Crystallisation Kinetics of Primary Mechanically Recycled Poly(l-lactic acid) and Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3396
Author(s):  
Luboš Běhálek ◽  
Jan Novák ◽  
Pavel Brdlík ◽  
Martin Borůvka ◽  
Jiří Habr ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Physical Properties ◽  
Structural Changes ◽  
The Other ◽  
Half Time ◽  
Crystallisation Kinetics ◽  
Isothermal Crystallisation ◽  
Melt Crystallisation ◽  
Kinetics Of ◽  
Crystallisation Rate

The physical properties and non-isothermal melt- and cold-crystallisation kinetics of poly (l-lactic acid) (PLLA) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) biobased polymers reprocessed by mechanical milling of moulded specimens and followed injection moulding with up to seven recycling cycles are investigated. Non-isothermal crystallisation kinetics are evaluated by the half-time of crystallisation and a procedure based on the mathematical treatment of DSC cumulative crystallisation curves at their inflection point (Kratochvil-Kelnar method). Thermomechanical recycling of PLLA raised structural changes that resulted in an increase in melt flow properties by up to six times, a decrease in the thermal stability by up to 80 °C, a reduction in the melt half-time crystallisation by up to about 40%, an increase in the melt crystallisation start temperature, and an increase in the maximum melt crystallisation rate (up to 2.7 times). Furthermore, reprocessing after the first recycling cycle caused the elimination of cold crystallisation when cooling at a slow rate. These structural changes also lowered the cold crystallisation temperature without impacting the maximum cold crystallisation rate. The structural changes of reprocessed PHBV had no significant effect on the non-isothermal crystallisation kinetics of this material. Additionally, the thermomechanical behaviour of reprocessed PHBV indicates that the technological waste of this biopolymer is suitable for recycling as a reusable additive to the virgin polymer matrix. In the case of reprocessed PLLA, on the other hand, a significant decrease in tensile and flexural strength (by 22% and 46%, respectively) was detected, which reflected changes within the biobased polymer structure. Apart from the elastic modulus, all the other thermomechanical properties of PLLA dropped down with an increasing level of recycling.

scholarly journals Effect of freeze‐dried durian skin nanofiber on the physical properties of poly(lactic acid) biocomposites

2020 ◽  
Author(s):  
Nurfarahin Mohd Nordin ◽  
Hazleen Anuar ◽  
Yose Fachmi Buys ◽  
Fathilah Ali ◽  
Sabu Thomas ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Physical Properties ◽  
Poly Lactic Acid ◽  
Freeze Dried

scholarly journals Antilisterial and physical properties of biopolymer films containing lactic acid bacteria

Food Control ◽  
2014 ◽  
Vol 35 (1) ◽  
pp. 200-206 ◽  
Author(s):  
Laura Sánchez-González ◽  
Jorge Ivan Quintero Saavedra ◽  
Amparo Chiralt
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Physical Properties

The Influence Capitalize of Properties Improvement for Reinforced Plastics by Resin Flow Control Molding Method

2012 ◽  
Vol 6 (4) ◽  
pp. 522-528 ◽  
Author(s):  
Naoki Mori ◽  
◽  
Kiyohito Gondou ◽  
Kohei Shimada ◽  
Takahiro Kitamura ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Flow Control ◽  
Physical Properties ◽  
Glass Fiber ◽  
Poly Lactic Acid ◽  
Resin Flow ◽  
Fiber Reinforced ◽  
Molding Method ◽  
Reinforced Plastics ◽  
Glass Fiber Reinforced

We are now engaged in the study on a resin flow control molding method in which molecules and fillers are positively oriented by displacing resin flows in the mold. We intend to confirm that the resin flow control molding method can properly control the orientation of fibers in glass fiber reinforced polypropylene moldings. We have also attempted to improve physical properties of poly-lactic acid molded by the resin flow control molding method. We have directly observed the process of filling resins into a glass-inserted mold to prove effectiveness of the resin flow control molding method.

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