Effect of Poly(l-lactide-co-ε-caprolactone) Macromonomer Composition on the Properties of Hot-Melt Adhesives with High Biomass Contents

Tailoring Wetting Ridge Dynamics on Hybrid Acrylic Polymers: The Impact of Mechanical Properties on Continuous Wetting

This study examined the relationships among the wetting speed, the polymer mechanical properties, and the resulting deformation characteristics of various graft copolymers synthesized from acrylic monomers and acrylated l-lactide and ε-caprolactone macromonomers (MMs). The mechanical properties of the polymer films were manipulated with minimal impact on their static contact angles with water by varying their MM composition. The focus was on wetting speeds prior to the onset of stick-slip behavior, where ridges were smoothly pulled over the surfaces, thereby producing a transient deformation indicative of a wave pulse. The height of the propagated ridge structures quickly converged to a steady-state value, depending on the wetting speed and polymer properties, regardless of the initial size. The results show that the propagated ridge height correlates with the wetting speed, and the data are well fitted by the Kelvin-Voigt model, which yields two key parameters: the maximum ridge height at the limit of zero velocity and the characteristic wetting speed. Both parameters correlated linearly with the lactide content in the MMs, and the characteristic wetting speed correlated linearly with crossover frequencies from the rheological master curves of the polymers. Furthermore, the characteristic wetting speed was correlated with the peel force required to remove polymer films from the steel plates, establishing a connection between dynamic wetting and adhesive behavior. Our findings shed light on the interdependence between the material composition, mechanical properties, and wetting behavior. The insights presented offer significant potential for designing materials with controlled wetting properties, particularly for applications where capillary flow and surface interactions play critical roles.

Study on a new type of environment-friendly polymer and its preliminary application as soil consolidation agent during tree transplanting

Transplanting trees with rhizospheric soil is an important way to facilitate tree survival in the process of landscaping and reforestation. Traditional way to prevent looseness of rhizospheric soil is forming soil balls around the roots with bags, boxes or rope wrapping, which is cumbersome, laborious and easy to break. This study is aimed to develop a new type of degradable environment-friendly polymer as soil consolidation agent to facilitate tree transplanting. In this paper, the KGM/CA/PVA ternary blending soil consolidation agent was prepared by using Konjac glucomannan (KGM), chitosan (CA) and polyvinyl alcohol (PVA) as raw materials. Through the verification and evaluation, the clay and sandy soil can be consolidated and formed into soil balls by the ternary blend adhesive, which was convenient for transportation. The preliminary application of the ternary blend adhesive in the transplanting process of sierra salvia, Japanese Spindle (Euonymus japonicus) and Juniperus sabina ‘Tamaricifolia’ confirmed that the application of soil consolidation agent can effectively solve the problem that the root ball of seedling is easily broken in the process of transplant. And the application of soil consolidation agent has no adverse effect on the growth of transplanted seedlings. The research and development of ternary blending soil consolidation agent and its preliminary application in seedling transplanting will provide a new solution to solve the problem of soil ball breakage in the process of seedling transplanting. This is an important stage in the development of new seedling transplanting technology. Therefore, the research and development of soil consolidation agent is of great significance.

Thermal Stability of Bio-Based Aliphatic-Semiaromatic Copolyester for Melt-Spun Fibers with Excellent Mechanical Properties

Flexible aliphatic poly(lactic acid) is introduced into polyethylene terephthalate through copolymerization to prepare biodegradable copolyester, which aims to solve the non-degradability of polyethylene terephthalate (PET) and realize the greening of raw materials. In this work, poly(ethylene terephthalate-co-lactic acid) random copolyesters (PETLAs) of lactic acid composition from 10 to 50% is synthesized via one-pot method. The chemical structure and composition, thermal property, and crystallization property of prepared PETLAs resin are characterized. The results shows that the introduction of LA segment forms random copolyester, and the flexible LA segment results in slight decrease in the glass transition temperatures (T_g ), melting point (T_m ), and crystallinity (X_c ) of the copolyesters. The thermal stability of PETLAs is better, and the initial decomposition temperature of PETLA-10 can reach 394 °C. The PETLAs resin exhibits good processability, and PETLAs fibers are prepared by melt spinning. The strength of PETLA-10 fiber can reach 260 MPa after drawing treatment, and the elongation at break can reach 130%. Taking advantage of their features, PETLAs as an innovative bio-based polymer are expected to achieve ecofriendly applications in the fields of fiber, plastic, and film.

Biodegradable copolyester poly(butylene-co-isosorbide succinate) as hot-melt adhesives

We modified poly(butylene succinate) (PBS) with sugar-based monomer isosorbide to improve the bond strength between PBS and metal interfaces and thereby alleviate the environmental problems caused by nondegradable hot-melt adhesives. We analyzed the efficiency of different catalysts in the synthesis of poly(butylene-co-isosorbide succinate) (PBIS) copolyesters. The thermal stability, thermodynamic characteristics, and melting viscosity of PBIS copolyesters were systematically evaluated by characterization. The results indicate that isosorbide can greatly improve the bond strength of the interface between PBS and the iron plate when copolyesters are used as hot-melt adhesives.

Biodegradable PBIS copolyesters can be used as hot-melt adhesives and tailored by varying the isosorbide content.