Cyclodextrin-based host-guest hierarchical fire retardants: Synthesis and novel strategy to endow polylactic acid fire retardancy and UV resistance.

β-Cyclodextrin (β-CD) with a cage-like supramolecular structure possesses the hydrophobic internal ring and external hydroxyl groups, which are beneficial for intramolecular interactions known as "host-guest" chemistry. This study presents a β-CD-based three-functions-in-one and host-guest fire retardant (βCD-MOF@Schiff base), which incorporates self-crosslinking Schiff base into its cavity and modification of its surface by metal-organic framework (MOF). With the presence of 5 wt% of βCD-MOF@Schiff base, the LOI value of PLA composites increased to 29 % and showed 15 %, 17 % and 62 % reductions in peak heat release rate (pHRR), total heat release (THR), and the yield of hazard gas carbon monoxide, respectively.

Regulation of polylactic acid using irradiation and preparation of PLA-SiO-ZnO melt-blown nonwovens for antibacterial and air filtration.

Since the COVID-19 pandemic, polypropylene melt-blown nonwovens (MBs) have been widely used in disposable medical surgical masks and medical protective clothing, seriously threatening the environment. As a bio-based biodegradable polymer, polylactic acid (PLA) has attracted great attention in fabricating MBs. However, there are still issues with the undesirable spinnability of PLA and the limited filtration and antibacterial performance of PLA MBs.

Mechanical, Thermal Stability, and Flame Retarding Properties of Phosphorus-Modified PET Blended with DOPO-POSS.

In this study, an antidroplet flame retardant system based on FRPET (phosphorus-containing copolyester) is constructed with DOPO-POSS (polyhedral oligomeric silsesquioxane containing DOPO) as an additive flame retardant. It is demonstrated that DOPO-POSS has good dispersibility at a lower amount. When the amount of DOPO-POSS is 9 wt %, the residual char of DOPO-POSS/FRPET at 700 °C increases to 23.

Solvothermal preparation of nitrogen-doped carbon dots with PET waste as precursor and their application in LEDs and water detection.

Developing novel, alternative ways to recycle PET waste, which has an important influence on reduction of landfilling and CO emissions, has always been a research hot spot for industry and academy. In this work, PET waste was adopted as precursor for the preparation of nitrogen-doped Carbon Dots (NCDs). Firstly, PET oligomers were obtained by alcoholysis of PET waste with ethylene glycol.

Simultaneously Enhancing the Fire Retardancy and Heat Resistance of Stereo-Complex-Type Polylactic Acid.

Polylactic acid (PLA) is considered to be the material with great application potential in the 21st century which has aroused wide research interest. However, PLA is a highly flammable material and exhibits low heat distortion temperature, which greatly limits its application in many fields. In this work, aluminum diethyl phosphinate (ADP) and poly (d-lactic acid) (PDLA) are used to improve fire retardancy and heat resistance of poly (l-lactic acid) (PLLA).

Three-dimensional crimped biodegradable poly(lactic acid) fibers prepared melt spinning and controlled structural reorganization.

Biodegradable three-dimensional crimped fibers were prepared by the side-by-side composite spinning of poly(lactic acid) (PLA) and low-melting point PLA (LM-PLA). The structural variation of the PLA/LM-PLA composite fibers during dry and wet heat treatment was explored systematically. It is shown that crystallization and disorientation were two key factors for the formation of the three-dimensional crimped structure of PLA/LM-PLA side-by-side composite fibers (SSCF).

Structure Mediation and Properties of Poly(-lactide)/Poly(-lactide) Blend Fibers.

Poly(-lactic acid) (PLLA) and poly(-lactic acid) (PDLA) blend as-spun fibers (50/50, wt.%) were prepared by melt spinning. Structure mediation under temperature and stress and properties of poly(-lactic acid)/poly(-lactic acid)(PLLA/PDLA) as-spun fibers were investigated by wide-angle X-ray scattering (WAXS) and differential scanning calorimetry (DSC).