Development of methods for encapsulation of viruses into polymeric nano‐ and microparticles for aquaculture vaccines

To meet an urgent need for improved vaccines against viral diseases in aquaculture, encapsulating the viruses into biodegradable and biocompatible polymers was suggested to protect viral antigens from premature degradation and gradually expose them to the immune system. We used water‐in‐oil‐in‐water emulsion to first encapsulate model red fluorescent polystyrene (PS) particles and then infectious salmon anemia virus (ISAV) into poly‐lactic‐co‐glycolic acid (PLGA) together with coumarin 6. A milder layer‐by‐layer method was applied to incorporate both PS and ISAV into chitosan (Cs)‐fluorescein isothiocyanate and alginate (Alg) followed by ionic crosslinking. All particles were characterized by dynamic light scattering, zeta‐sizer, fluorescence, transmission‐ and scanning electron microscopy. Successful encapsulation of PS beads and ISAV into PLGA, Cs, and Alg was accomplished. The prepared particles were of different size, surface charge density, and morphology. This yields opportunities for further developments of these structures as vaccine candidates to be delivered by injection or oral administration. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40714.     

Bioprinting a cell-laden matrix for bone regeneration: A focused review

Although many efforts have been made to regenerate the bone lesions, existing challenges can be mitigated through the development of tissue engineering scaffolds. However, the weak control on the microstructure of constructs, limitation in preparation of patient-specific and multilayered scaffolds, restriction in the fabrication of cell-laden matrixes, and challenges in preserving the drug/growth factors' efficacy in conventional methods have led to the development of bioprinting technology for regeneration of bone defects. So in this review, conventional 3D printers are classified, then the priority of the different types of bioprinting technologies for the preparation of the cell/growth factor-laden matrixes are focused. Besides, the bio-ink compositions, including polymeric/hybrid hydrogels and cell-based bio-inks are classified according to fundamental and recent studies. Herein, different effective parameters, such as viscosity, rheological properties, cross-linking methods, biodegradation biocompatibility, are considered. Finally, different types of cells and growth factors that can encapsulate in the bio-inks to promote bone repair are discussed, and both in vitro and in vivo achievement are considered. This review provides current and future perspectives of cell-laden bioprinting technologies. The restrictions and challenges are identified, and proper strategies for the development of cell-laden matrixes and high-performance printable bio-inks are proposed.     

Synergistic reinforcing of poly(lactic acid) by poly(butylene adipate-co-terephthalate) and alumina nanoparticles

Biodegradable poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blends and PLA/PBAT/Al₂O₃ nanocomposites were fabricated via solution blending. The influence of PBAT and Al₂O₃ content on the thermal stability, flexural properties, impact strength, and morphology of both the PLA/PBAT blends and the PLA/PBAT/Al₂O₃ nanocomposites were investigated. The impact strength of the PLA/PBAT/Al₂O₃ nanocomposites containing 5 wt% PBAT increased from 4.3 to 5.2 kJ/m² when the Al₂O₃ content increased from 0 to 1 wt%. This represents a 62% increase compared to the impact strength of pristine PLA and a 20% increase compared to the impact strength of PLA/PBAT blends containing 5 wt% PBAT. Scanning electron microscopy imaging revealed that the Al₂O₃ nanoparticles in the PLA/PBAT/Al₂O₃ nanocomposites function as a compatibilizer to improve the interfacial interaction between the PBAT and the PLA matrix.     

Effect of five saturated fatty acids on the properties of sweet‐potato‐starch‐based films

To fully explore the influences of saturated fatty acids (SFAs) on the properties of sweet‐potato‐starch (SPS)‐based films, five SFAs were chosen to add to SPS. The SPS‐based films were prepared by casting. The microstructure, mechanical, optical, water vapor barrier, and thermal properties of the films were investigated. The 2.0% (w/w, on the basis of starch) SFA significantly changed the SPS pasting characteristics in the peak viscosity, breakdown, and other feature point viscosity values as determined by a Rapid Visco Analyser. The amylose molecular weights decreased as measured by high‐performance size exclusion chromatography. A thermal study with differential scanning calorimetry suggested that the addition of SFA increased the onset temperature and peak temperature. Scanning electronic microscope (SEM) images showed a continuous and uniform structure in the films with SFA. The SPS–SFA composite films showed lower light transmission and elongation at break than the control. Compared with the control films, the addition of SFA increased the tensile strength and decreased the water vapor permeability of the films. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41380.     

Synthesis and characterization of polysaccharide hydrogel based on hydrophobic interactions

Hydrogels based on hydrophobic, or micellar interactions, are physically crosslinked hydrogels which are an attempt to overcome the poor mechanical properties of traditional, chemically crosslinked gels, such as low shear strength. We have prepared a polysaccharide-based hydrogel with physical crosslinks via hydrophobic interactions. In this work, we have synthesized hydrogel by grafting a hydrophobic moiety dioctylamine onto hydrophilic precursor carboxymethyl cellulose (CMC) through an amide bond formation, where ~33% of the carboxyl group in CMC was reacted with dioctylamine. The thermosensitive hydrogel can arrest 100 mL of deionized water per gram of gelator within few seconds. It showed the moderate rheological property. The hydrogel is nontoxic and does not show any adverse to human hemoglobin. It is a CMC based a unique gelator with high biocompatibility represent to be useful materials for biomedical application. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47665.     

In situ chemically crosslinked chitosan membrane by adipic acid

Adipic acid, which is nontoxic, was used to dissolve chitosan. The chitosan/adipic acid solution was used to prepare chitosan membrane. After being heated at 80–100°C, the membrane was in situ chemically crosslinked by adipic acid, as verified by Fourier transform infrared and wide‐angle X‐ray diffractometer analysis. The crosslinked membrane did not collapse even without treatment in alkaline solution. In addition, the in situ crosslinking reaction was studied. The crosslinking degree (CLD) was quantitatively calculated based on the mass of water produced. The results showed that CLD was positively related to both heating temperature and time. Results of kinetic of crosslinking reaction suggested that the amidation was in agreement with the first‐order rate equation and that the temperature effect could be described with the Arrhenius equation. The results of weight loss of chitosan membrane in phosphate‐buffered solution (pH = 7.4) indicated that the best water resistance of chitosan membrane was obtained at 90°C. In brief, a straightforward, nontoxic, environment‐friendly, and economical chemically crosslinking approach has been developed for chitosan materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Surface and degradation properties of thermoplastic blends from albumin and zein‐based plastics

The use of traditional petroleum‐based thermoplastics in food packaging applications pose an environmental hazard, as their lack of biodegradability creates waste that environmental systems are unable to cope with. To address this issue, the investigation of surface, biodegradation, and water solubility properties of the albumin and zein thermoplastic blends plasticized with glycerol and mixed with varying amounts of low‐density polyethylene (LDPE) is conducted. When subjected to soil burial, albumin as a bioplastic completely biodegrades within two months, while a zein‐based bioplastic is more resilient to attacks from microbes within the soil (4.34% of intial mass remains). If albumin and zein proteins are used in the production of thermoplastics in tandem with LDPE, it could be possible to produce a plastic that will naturally biodegrade over time, decreasing the environmental impact of the use of thermoplastics in medical and food packaging applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44646.     

Fully bio‐based poly(ɛ‐capolactone)/poly(lactide) alternating multiblock supramolecular polymers: Synthesis,crystallization behavior,and properties

Supramolecular poly(?‐capolactone)/poly(lactide) alternating multiblock copolymers were prepared by UPy‐functionalized poly(lactide)‐b‐ poly(?‐capolactone)‐b‐ poly(lactide) copolymers. The prepared supramolecular polymers (SMPs) exhibit the characteristic properties of thermoplastic elastomers. The stereo multiblock SMPs (sc‐SMPs) were formed by blending UPy‐functionalized poly(l ‐lactide)‐b‐ PCL‐b‐ poly(l ‐lactide) (l ‐SMPs) and UPy‐functionalized poly(d ‐lactide)‐b‐ PCL‐b‐ poly(d ‐lactide) (d ‐SMPs) due to stereocomplexation of the PLLA and PDLA blocks. Sc‐SMPs with low content of d ‐SMPs (≤20%) are transparent, elastic solids, while those having high d ‐SMPs content are opaque, brittle solids. The effects of l ‐SMPs/d ‐SMPs mixing ratios on thermal, crystallization behaviors, crystal structure, mechanical and hydrophilic properties of sc‐SMPs were deeply investigated. The incorporation of UPy groups depresses the crystallization of polymer, and the stereocomplex formation accelerates the crystallization rate. The used initiator functionalized polyhedral oligomeric silsesquioxanes causes a different effect on the crystallization of PLA and PCL blocks. The tensile strength and elongation at break of l _d /d _d ‐SMPs (d represents the initiator diethylene glycol) are significantly larger than that of l _p /d _p ‐SMPs (p represents the initiator polyhedral oligomeric silsesquioxanes), and their heat resistance and hydrophilicity can be also modulated by the l ‐SMPs/d ‐SMPs mixing ratios and the different initiators. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45575.     

Thermoplastic films from plant proteins

Films developed by thermoprocessing of plant proteins have better mechanical properties and are relatively inexpensive and environmentally friendly compared to casting films from solutions. Common plant proteins such as soyproteins, wheat gluten, and corn zein and proteins from lesser grown cereal crops such as peanut, barley, sunflower, and sorghum have all been injection or compression molded into films. Since plant proteins are non‐thermoplastic, it is necessary to chemically or physically modify the proteins and make them thermoplastic. Extensive studies on the addition of plasticizers, pre‐treatment of proteins with alkali, steam, chemical modifications such as acetylation and blending of the proteins with other biopolymers and synthetic polymers have been done to modify proteins and develop thermoplastics. Despite the extensive work, thermoplastic films obtained from plant proteins do not have the properties that can meet or exceed properties of films made from synthetic polymers. Poor water stability and brittleness are the two major limitations of plant protein films. This review presents an overview of the methods and processing conditions used to develop thermoplastic films from plant proteins and the properties of the films. A critical assessment of approaches that have been used so far, limitations of these approaches and potential considerations for future studies to overcome the current limitations have been discussed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 729‐738, 2013     

Polyhydroxybutyrate and hydroxyvalerate production by Bacillus megaterium strain A1 isolated from hydrocarbon‐contaminated soil

In this study, we attempted to find an alternative microbial resource as a bioplastic producer. Among all of the isolates, the A1 strain produced 44% poly(β‐hydroxybutyrate) (PHB) in proportion to its dry cell weight. The molecular identification of the 16S RNA gene showed that this bacterium was a strain of Bacillus megaterium with the accession number KC579390. The optimization studies led us to the conclusion that the highest poly(β‐hydroxybutyrate‐co‐hydroxyvalerate) (PHBV) production was 78% when 5% molasses was used as the carbon source at pH 6 and 35°C after 60 h of incubation. Attenuated total reflectance Fourier transform infrared (FTIR) spectroscopy and H‐NMR were used for chemical characterization. Differential scanning calorimetry was used to determine the thermal properties of the PHB and PHBV that were synthesized with sucrose and molasses as carbon sources, respectively. The FTIR spectra of the polymers were characterized by typical absorption bands at 1715–1720 cm^?1 for amide‐bound C?O bands and 1261–1279 cm^?1 for an ester‐bound C? O band. The molecular weights of PHB and PHBV synthesized with sucrose and molasses were calculated as 428 and 498 kDa, respectively, according to the viscometric method. This study indicated that the B. megaterium strain A1 is an alternative microbial resource as a bioplastic producer. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40530.     

Highly permeable biomimetic reverse osmosis membrane with amphiphilic peptide stabilized aquaporin as water filtering agent

The shortage of fresh water is one of the most critical problems our society must address. The most commonly accepted method to produce fresh water is by membrane systems. Since the discovery of aquaporins (AQPs) (water channel proteins), researchers have been trying to incorporate them as functional units in biomimetic membranes to achieve superior water permeability and solute rejection. However, it still remains challenging due to the lack of an effective strategy to stabilize AQPs and fabricate robust membranes. Here, we report the utilization of an amphiphilic peptide (BP1) to stabilize AQPs and use the resulting protein–BP1 complex for desalination purposes. We demonstrated the secondary structure and stability of protein–BP1 complex in aqueous solution using circular dichroism and transmission electron microscopy. The resulting membrane with aquaporin incorporation showed water permeability of 12.33 LMH, improved 28% compared to mutant control membrane, and 83.6% compared to traditional polyamide membrane, while maintaining the high sale rejection (96%). These results demonstrate a great potential of this new incorporating technique for desalination applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46169.     

Magnetic chitosan-based aerogel decorated with polydimethylsiloxane: A high-performance scavenger for oil in water

Most ingredients used to construct porous substrate of hydrophobic magnetic absorbent for oil/water separation are toxic, environmentally incompatible and difficult to degrade. With the purpose of solving this problem, a magnetic chitosan (CS)-based aerogel decorated with polydimethylsiloxane (PDMS) was successfully fabricated in this work. The magnetic porous substrate was built by the electrostatic interactions between CS, itaconic acid and Fe₃O₄ nanoparticles (FeNPs) in water solution, followed by a freeze-drying process. The hydrophobic properties were rendered to the substrate by the crosslinking reaction of PDMS. Owing to the low density (0.0655 g/cm³) and high porosity (92%), the prepared aerogel displayed high absorption capacities (8.89–22.38 g/g) towards the testing organic liquids. The silylation process provided the aerogel with excellent hydrophobic properties (water contact angle, 147.1°), resulting in selectively absorbing oil from immiscible oil/water mixture and water-in-oil emulsion. Due to the uniformly distributed FeNPs, the remote control of the aerogel by external magnetic field was acquired, the saturation magnetization of which was 11.22 emu/g. Furthermore, the aerogel could also continuously separate heavy oil from water by acting as filter. The experimental results indicate that this renewable, environmentally benign and bifunctional aerogel has great potential in oily wastewater remediation.     

Preparation of hybrid PU/PCL fibers from steviol glycosides via electrospinning as a potential wound dressing materials

In this study, the synthesis and application of biocompatible steviol glycosides based polyurethane/poly (ε-caprolactone) (PU/PCL) fibers was performed by electrospinning as a potential wound dressing materials that can be used for the closure of nonhealing wounds. During electrospinning, steviol glycoside-based polyurethane structures were used in blend formation with poly (ε-caprolactone) for easy producibility. Steviol glycosides are a natural abundant and easily accessible source as the main component of the wound dressing material due to their free hydroxyl groups, high biocompatibility, and hydrophilicity. The structure of steviol glycosides is composed of saccharide units and the free OH groups. Thus, steviol glycosides act as a crosslinker within the polyurethane structure and provides mechanical strength. For the production of steviol glycosides based PU/PCL fibers first, the steviol glycosides as a monomer were isolated from the stevia rebudiana. Then, polyurethane structures containing stevia glycoside were synthesized with hexamethylene diisocyanate, lactose and PEG-200 by solution polymerization technique. PCL was added to the prepared polyurethanes in a ratio of 1:2 and formation of nanofiber structure. The prepared wound dressing material was characterized by Fourier transform infrared, atomic force microscopy, and scanning electron microscope techniques. Swelling degree, water content and oxygen permeability assay of the steviol glycosides based PU/PCL wound dressing material was determined. In biocompatibility test, cell viability value of PU/PCL fibrous materials in indirect cytotoxicity test was determined as 86.9% and cell adhesion on hybrid PU/PCL fibers was showed as morphological. In accordance with this target, the steviol glycosides based PU/PCL wound dressing material can be produced easily and low cost. As a result, the wound dressing materials obtained with their high biocompatibility and low costs will be an effective and fast method for the healing of open wounds of diabetics.     

Natural resources derived biocomposites as potential carriers of green pesticides in agricultural field: Designing and fabrication of a pot-like device

Hemp fibers (HF) are used as filler in pectin to produce biocomposites. To improve the compatibility of the filler with the polymeric matrix, HF are treated through mechanochemically assisted alkaline attack. The effect of the treatment time on the morphology of HF is investigated through atomic force microscopy and infrared spectroscopy. Cinnamic acid, a green pesticide, is added to the composites in order to test the capability of such materials to act as potential devices in the agricultural field. Analysis of thermal, mechanical, barrier properties and surface energy are evaluated on biocomposites and compared either to unfilled pectin or to composites filled with untreated HF. The release of cinnamic acid is evaluated and found to be dependent on the fibers' treatment time. The design and the fabrication of a pot prototype is also reported. The manufacture appears promising as green functional container for plants to be implanted in the ground.     

Functionalized chitosan with butylammonium ionic liquids for removal of Cr(VI) from aqueous solution

Environmental pollution by heavy metals is currently a problem of great concern for human health. In this context, this study aims to contribute with the synthesis and characterization of chitosan functionalized with three different ionic liquids (n-butylammonium acetate, sec-butylammonium acetate, and tert-butylammonium acetate) followed by its application in hexavalent chromium effluent treatment. The adsorbents synthesized (ChN, ChS, and ChT) were characterized by SEM, EDS, FTIR, BET, RDD, PSD, and XRD techniques. Afterward, the influences of temperature, contact time, and pH on the Cr(VI) adsorption process were evaluated. The solution with pH 3 displayed the highest adsorption capacities (107.31, 104.60, and 107.97 mg.g^-1 for ChN, ChS, and ChT, respectively). The kinetic data were better adjusted to the Weber-Morris kinetic model with an ideal time of 2 h. Furthermore, the influence of temperature was evaluated using the Freundlich and Langmuir isotherms, with maximum capacities of 142.05 (ChN), 131.58 (ChS), and 146.63 mg.g^-1 (ChT). The adsorbent displayed enhanced adsorption properties in comparison with raw chitosan by an intensification of the electrostatic interaction between amino groups and hexavalent chromium. Finally, the reusability was investigated, and significant results were observed (84.33 ± 4.87%) in the adsorption process after 4 cycles.     

Thermosets resins prepared from soybean oil and lignin derivatives with high biocontent,superior thermal properties,and biodegradability

A bio-based monomer, methacrylated vanillyl alcohol (MVA), had been synthesized from vanillyl alcohol with methacrylate anhydride (MAA) via a solvent-free, efficient method. The synthesis of MVA was confirmed by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (¹H NMR). It was used to copolymerize with acrylated epoxidized soybean oil (AESO) to prepare a bio-based resin (MVA–AESO). Excess MAA of MVA synthesis was further used to modify AESO with hydroxyl groups, generating (MVA–MAESO) with higher unsaturation degree. Their chemical structure and modification were characterized using ¹³C NMR and Fourier transform infrared analyses. Pure AESO and MVA resins were used to compare with MVA–AESO and MVA–MAESO in terms of their viscosity, curing performance, mechanical, and thermal properties. The synthesized MVA–AESO and MVA–MAESO resins showed much lower viscosities than pure AESO due to the dilution of MVA. In addition, the incorporation of MVA reduced curing temperatures, activation energies which caused MVA–AESO and MVA–MAESO had higher curing degree than pure AESO. With the combination of MVA and modification of MAA, flexible AESO networks exhibited superior flexural properties, storage modulus, glass-transition temperature, and thermal stability. Furthermore, the biodegradation of the formulated bio-based resins were also investigated. Results showed that the addition of monomer and the increase in the content of CC bonds did not significantly affect the biodegradability of AESO, which may be due to the fact that the degradable groups of AESO were not affected. This environmentally friendly, low (volatile organic) resin, prepared by a high efficiency and environmental protection synthetic route, can potentially replace typical petroleum-based thermosets for the production environmentally friendly thermosetting resins. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48827.     

Preparation and characterization of a novel gelatin–poly(vinyl alcohol) hydrogel film loaded with Zataria multiflora essential oil for antibacterial–antioxidant wound‐dressing applications

This study was performed to evaluate the properties of poly(vinyl alcohol) (PVA), gelatin, and PVA–gelatin dispersions and films enriched with Zataria multiflora essential oil (ZO). The results reveal that the ζ potential, particle size, and viscosity values and the antioxidant and antibacterial activities of the dispersions changed significantly with the addition of ZO to the polymer matrix. Changes in the properties of the dispersions suggested the presence of interactions between PVA or gelatin and ZO. Such interactions could affect the mechanical and water‐barrier properties of the films. ZO induced remarkable decreases in the tensile strength, elastic modulus, and swelling and increases in the elongation at break, solubility, and water‐vapor permeability of the films. Scanning electron microscopy analyses proved the impact of ZO on the film morphology, which affected the film properties, including the mechanical and water‐barrier properties. The addition of ZO to the polymer led to a coarse film microstructure because of the hydrophobic ZO aggregates, which produced discontinuities in the film matrix. ZO considerably increased the antioxidant and antibacterial activities of the dispersions. Pseudomonas aeruginosa was the most resistant bacteria. The improved antioxidant and antimicrobial activities of the PVA–ZO and gelatin–ZO indicated that such products could effectively be used as wound dressings. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45351.     

Utilization of ramon seeds (Brosimum alicastrum swarts) as a new source material for thermoplastic starch production

The development and characterization of biodegradable polymers deriving from renewable natural sources has attracted much attention. The aim of this work was to partially characterize a thermoplastic starch obtained from the starch of seeds from the ramon tree (TPS‐RS) as an option to substitute thermoplastic starch from corn (TPS‐CS), in some of its applications. At 55% of relative humidity (RH), TPS‐RS had higher tensile strength and deformation than TPS‐CS. X‐ray diffraction analysis showed similar values in residual crystallinity (percentage of crystallinity that remains after plasticization process) in both TPS. The SEM micrographs showed a few remnant granular structures in the TPS‐RS. The FTIR showed a greater intensity in band at 1016 cm^?1 in the TPS‐CS and TPS‐RS in comparison with their corresponding native starch, indicating an increase in the amorphous region after plasticization. The TGA analysis showed greater thermal stability in TPS‐CS (340 °C) compared with TPS‐RS (327 °C). In addition, the glass transition temperature in both TPS was 24 °C. The results obtained represent a starting point to potentialize the use of TPS‐RS instead of TPS‐CS for the development of new biodegradable materials for practical applications in different areas. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44235.     

Recent developments in polymers derived from industrial lignin

Lignin is an aromatic polymer that makes up 15–30% of the cell walls of terrestrial plants. While lignin's role in facilitating water transport through the vasculature, providing rigidity and acting as a defense against pests and pathogens is important for the plant's survival, industries that process plant biomass for the production of biofuels and bio‐based chemicals have historically primarily been interested in the cell wall polysaccharides, especially cellulose. Consequently, lignin is generated in large quantities as a by‐product that is often burned to generate heat and electricity, or that is used in low‐value applications. It is becoming clear that, rather than treating it as waste, lignin is very suitable for the production of enhanced composites, carbon fibers, and nanomaterials, which offers both economic and environmental benefits. This review highlights recent uses of these polymers as adsorbents, flocculants, adhesives, anti‐oxidants, energy storing films, and vehicles for drug delivery and gene therapy. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42069.     

Hydrolytic degradation and crystallization behavior of linear 2‐armed and star‐shaped 4‐armed poly(l‐lactide)s: Effects of branching architecture and crystallinity

“Linear” aliphatic polyesters composed of two poly(l ‐lactide) arms attached to 1,3‐propanediol and “star‐shaped” ones composed of four poly(l ‐lactide) arms attached to pentaerythritol (2‐L and 4‐L polymers, respectively) with number‐average molecular weight (M_n) = 1.4–8.4 × 10⁴g/mol were hydrolytically degraded at 37°C and pH = 7.4. The effects of the branching architecture and crystallinity on the hydrolytic degradation and crystalline morphology change were investigated. The degradation mechanism of initially amorphous and crystallized 2‐L polymers changed from bulk degradation to surface degradation with decreasing initial M_n; in contrast, initially crystallized higher molecular weight 4‐L polymer degraded via bulk degradation, while the degradation mechanism of other 4‐L polymers could not be determined. The hydrolytic‐degradation rates monitored by molecular‐weight decreases decreased significantly with increasing branch architecture and/or higher number of hydroxyl groups per unit mass. The hydrolytic degradation rate determined from the molecular weight decrease was higher for initially crystallized samples than for initially amorphous samples; however, that of 2‐L polymers monitored by weight loss was larger for initially amorphous samples than for initially crystallized samples. Initially amorphous 2‐L polymers with an M_n below 3.5 × 10⁴g/mol crystallized during hydrolytic degradation. In contrast, the branching architecture disturbed crystallization of initially amorphous 4‐L polymers during hydrolytic degradation. All initially crystallized 2‐L and 4‐L polymers had δ‐form crystallites before hydrolytic degradation, which did not change during hydrolytic degradation. During hydrolytic degradation, the glass transition temperatures of initially amorphous and crystallized 2‐L and 4‐L polymers and the cold crystallization temperatures of initially amorphous 2‐L and 4‐L polymers showed similar changes to those reported for 1‐armed poly(l ‐lactide). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41983.