Unsaturated Poly Research Articles

Synthesis and Characterization of New Unsaturated Degradable Poly(ether ester amide)s Containing Ethylene Oxide Moieties

A series of novel biodegradable unsaturated poly(ether ester amide)s (PEEAs) have been successfully prepared through interfacial polycondensation of 1,6-hexanediamine and unsaturated diacylchlorides containing ethylene oxide moieties linked to maleic anhydride by ester. The structures of PEEAs are verified by FT-IR and NMR spectra. The DSC and TGA measurements demonstrate the obtained polymers are amorphous and stable up to 300°C under nitrogen. Synthesized PEEAs show good hydrophilicity and improved solubility. The rate of hydrolytic degradation performed in the phosphate buffer solution (pH = 7.2) at 37°C increases with increasing the number of ether linkages per repeat unit in polymers. The degradation results indicate that PEEAs are hydrolyzable in a rapid and steady way.

Mechanical Strength of Glass-fibers Cloth (GFC) Reinforced Novel Environment Degradable Unsaturated Poly(ester-amide) Composites

A new type of degradable unsaturated poly(ester-amide), viz. maleic anhydride-phthalic anhydride-ethylene glycol-neopentylene glycol-caprolactam copolymer was prepared by melt polycondensation and characterization. The glass-fiber cloth (GFC) was used to boost up the new unsaturated poly(ester-amide). Mechanical strength of GFC/unsaturated poly(ester-amide) composites with different GFC content was measured. The results show mechanical strength of GFC/unsaturated poly(ester-amide) composites has maximum values (compressive strength 174.6 MPa, flexural strength 283.8 MPa, impact strength 123.1 KJ/m2), as GFC content increased, the cross-linked unsaturated poly(ester-amide) could be hydrolyzed completely in 1.0 M NaOH standard solution at room temperature.

Synthesis and characterization of a potential material as internal fixation of bone fracture

A new unsaturated poly (ester–amide) viz phthalic anhydride–maleic anhydride–hexane diamine–ethylene glycol–neopentylene glycol copolymer was prepared by melt polycondensation and characterized after sealed end with benzyl alcohol. Mechanical properties and degradation behavior of the cross-linked unsaturated poly (ester–amide) were measured. Moreover, the hydrolysis behavior of cross-linked unsaturated poly (ester–amide) in 1.0 mol/L NaOH standard solution at room temperature was also studied. At the same time, preliminary biocompatibility under mice skin was evaluated. All the preliminary results suggested that the copolymer might be a potential bone internal fixation material.

Dynamic mechanical properties and thermal degradation process of the compositions obtainedfrom unsaturated poly(ester urethanes) cross-linked with styrene

Dynamic mechanical and thermal properties of poly(ester urethanes) (PEU) cross-linked with styrene have been studied. The investigated polyurethanes were obtained from 4,4′-diphenylmethane diisocyanate and unsaturated oligo(alkyleneester)diol based on cis-2-butene-1,4-diol. The conducted analyses dealt with the correlation between the chemical structure of poly(ester urethanes) and their ability to phase separate as well as their thermal stability. The products of PEU thermal degradation were characterized using infrared spectroscopy.

Calcium polyphosphate fibers/unsaturated poly(ester‐amide) composites for bone‐fixation materials

AbstractA new type of unsaturated poly(ester‐amide) viz maleic anhydride‐phthalic anhydride‐propylene glycol‐neopentylene glycol‐glycin copolymer was prepared by melt polycondensation and characterized after sealed end with cyclohexanol. Mechanical strength of the crosslinked unsaturated poly(ester‐amide) with different heat‐treatment conditions was measured. Calcium polyphosphate fibers (CPPF) were used to boost up the new unsaturated poly(ester‐amide), mechanical strength, degradation, and hydrolysis behavior of CPPF/unsaturated poly(ester‐amide) composites with different CPPF content were measured. All the preliminary results suggested that the CPPF/unsaturated poly(ester‐amide) composites might be potentially used as a new type of bone‐fixation material. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers

A new type of unsaturated poly(ester-amide): Synthesis and compressive strength

A new type of unsaturated poly(ester-amide) was prepared by melt polycondensation and characterized after sealed end with benzyl alcohol by Fourier transform infrared spectroscopy, gel permeation chromatography (GPC) and thermal gravimetric analysis (TGA). The compressive strength of unsaturated poly(ester-amide) with different heat treatment conditions was measured after depth cross-linked. The degradation properties of depth cross-linked unsaturated poly(ester-amide) were studied in pH 7.4 phosphate buffer at 37 °C and the compressive strength loss was measured. Hydrolysis behavior of depth cross-linked unsaturated poly(ester-amide) was also carried out in 1.0 mol/L NaOH standard solution at room temperature. All the preliminary results suggested that the copolymer might be potentially used as a new type of bone fixation material.

Preparation of unsaturated poly(ε‐caprolactone) with a new titanium alkoxide initiator

AbstractTitanium alkoxides are widely used in the ring‐opening polymerization of ε‐caprolactone. In this study, functional poly(ε‐caprolactone) was synthesized with a new titanium initiator by a two‐step procedure: First, the titanium initiator, with an unsaturated group, was prepared by a classical organic reaction between 2‐hydroxyethylmethacrylate or 2‐allyloxyethanol with titanium tetrapropoxide; then, we initiated the polymerization of the ε‐caprolactone monomer in a glass reactor or twin‐screw extruder. By means of NMR spectroscopy, the structures of the initiators and polymers were determined. When 2‐hydroxyethylmethacrylate was used, there was a side reaction (transesterification) during the preparation of the initiator, and so it was impossible to obtain the expected product. With 2‐allyloxyethanol, the designed titanium initiator was synthesized with high purity, and the allyl moiety remained intact after the polymerization of ε‐caprolactone. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Effect of Cyclopentadienyl and Anionic Donor Ligands on Monomer Reactivities in Copolymerization of Ethylene with 2-Methyl-1-pentene by Nonbridged Half-Titanocenes−Cocatalyst Systems

Copolymerization of ethylene (E) with 2-methyl-1-pentene (2M1P) took place with rather efficient 2M1P incorporation by using the Cp*TiCl2(O-2,6-iPr2C6H3) (1)−MAO catalyst system, whereas the 2M1P incorporations by the Cp2ZrCl2, [Me2Si(C5Me4)(NtBu)]TiCl2, Cp‘TiCl2(NCtBu2) [Cp‘ = Cp (3), Cp* (4)], and Cp*TiCl3−MAO catalyst systems were negligible under the same conditions. The effects of substituents in both the cyclopentadienyl and the aryloxide ligands toward the catalytic activities and the 2M1P incorporations were explored, and use of both Cp* and 2,6-diisopropylphenoxy ligands was found to be important to obtain poly(ethylene-co-2M1P)s with rather efficient and uniform 2M1P incorporations as well as with notable catalytic activities. No distinct differences in the 2M1P incorporations were seen in the copolymerization by 1 in the presence of various cocatalysts [methylaluminoxane (MAO), methylisobutylaluminoxanes (MMAOs), borates], and the nature of ligands directly affects the 2M1P incorporation. Copolymerizations of ethylene with 7-methyl-1,6-octadiene (MOD) by 1,3,4−MAO catalyst systems proceeded at remarkable rates with efficient exclusive incorporation of monoolefins (without incorporating trisubstituted olefin), affording high molecular weight unsaturated poly(ethylene-co-MOD)s with high MOD contents. The MOD contents in the resultant copolymers in the ethylene/MOD copolymerization by 1,3,4−MAO catalyst systems were thus closely related to those in the ethylene/1-octene copolymerizations under similar conditions.

Biodegradation of unsaturated poly(ester-amide)s and their hydrogels

The biodegradability of both unsaturated (UPEA) and saturated (SPEA) poly(ester-amide)s and a series of hydrogels (UPEA-G) fabricated from UPEA and poly(ethylene glycol) diacrylate (PEG-DA) was examined as a function of PEA chemical structures in both phosphate buffered saline (PBS) and α-chymotrypsin solutions. Based on the weight loss data, α-chymotrypsin had a much more profound effect on the hydrolyses of UPEA, SPEA polymers (up to 32% weight loss on day 1 for FPBe) and UPEA-G hydrogels (up to 32% weight loss on day 31 for FPBe-G28) than a PBS buffer (less than 10% for polymers and 16% for hydrogels). The changes in elastic moduli and the interior morphology of the hydrogels in both PBS buffer and α-chymotrypsin solutions were also monitored for 2 months, and the hydrogels’ crosslinking density ( n e) and molecular weight between crosslinks ( M c) before and after biodegradation were then examined as a function of biodegradation time, enzyme concentration, and different chemical structure of precursors. The differences in biodegradation rates among PEA polymer and UPEA-G hydrogels are ascribed to differences in hydrophilicity and saturated or unsaturated structure of the polymers and hydrogel precursors. Our results showed that, by changing the concentration of α-chymotrypsin, the type of UPEA precursors and their feed ratio, the UPEA-G hydrogels could have controllable biodegradability, which is quite desirable for a wide range of biomedical and pharmaceutical applications.

Synthesis, characterization, and biodegradation of copolymers of unsaturated and saturated poly(ester amide)s

AbstractA new family of biodegradable copolymers of unsaturated poly(ester amide)s (UPEAs) and saturated poly(ester amide)s (SPEAs) based on L‐phenylalanine, aliphatic dicarboxylic acids, and aliphatic dialcohols was synthesized by solution polycondensation and characterized. These unsaturated/saturated poly(ester amide) copolymers (USPEAs) were obtained in fairly good yields with N,N‐dimethylacetamide as the solvent. The molecular weights (Mn and Mw) of the USPEAs measured by GPC ranged from 15 to 60 kg/mol with a molecular weight distribution of 1.07–1.63. The chemical structures of the USPEAs were confirmed by both IR and NMR spectra. The USPEA copolymers had glass transition temperatures lower than that of pure UPEA but higher than that of pure SPEA. An increase in the unsaturated component in the USPEA copolymers led to an increase in their glass transition temperatures. The solubility of the copolymers was good in N,N‐dimethylacetamide and dimethyl sulfoxide but poor in water, acetone, methanol, and ethyl acetate. The preliminary in vitro biodegradation properties of the USPEA copolymers were investigated in both pure phosphate buffered saline (PBS) buffer and α‐chymotrypsin solutions. The copolymers showed significantly faster weight loss in an enzyme solution than in a pure PBS buffer. Upon the adjustment of the unsaturated‐to‐saturated diester monomer feed ratio, the obtained USPEA copolymers could have controlled chemical and physical properties, such as glass transition temperatures, solubility, and biodegradability, which could easily extend their applications to biomedical and pharmaceutical areas. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1595–1606, 2007

Tailor‐made unsaturated poly(ester‐ amide) network that contains monomeric lactate sequences

AbstractA novel unsaturated poly(ester‐amide) network (UPEAN) that contains isolated CC double bonds, monomeric lactate sequences, rigid benzyl side‐groups, amide groups and crosslinking points has been designed and synthesized. The structure of the intermediate and UPEAN was verified with Fourier transform infrared spectroscopy. Pores in UPEAN generated in situ were examined with scanning electron microscopy. Differential scanning calorimetry analysis shows that UPEAN is amorphous and its glass transition temperature is around 34 °C. It is found that UPEAN exhibits thermosensitive shape‐recovery characteristics. The maximum percentage weight loss of UPEAN is 10 and 42% after immersing the samples in active sludge at ambient temperature for 146 days and in 0.1 mol L−1 phosphate‐buffer saline at 37 °C for 103 days, respectively, which suggests that UPEAN is degradable. Copyright © 2007 Society of Chemical Industry

Crosslinking of poly(silyl ester)s containing fumaryloxyl units in the main chain and characteristics of the crosslinked products

AbstractTwo unsaturated poly(silyl ester)s that contained innoxious fumaryloxyl units in the main chain were prepared by the polycondensation reaction of 1,5‐dichloro‐1,1,5,5‐tetramethyl‐3,3‐diphenyltrisiloxane or 1,3‐dichlorotetramethyldisiloxane with di‐tert‐butyl fumarate under nitrogen at 100°C for 1–3 days. To investigate the crosslinking reaction of the unsaturated poly(silyl ester)s, the two unsaturated poly(silyl ester)s were crosslinked in the presence of 2,2′‐azobisisobutyronitrile as a radical initiator. After the crosslinking, the unsaturated poly(silyl ester)s, which were viscous liquids, turned into solid products. The characterization of the two poly(silyl ester)s and the crosslinked products included infrared spectroscopy, 1H‐NMR spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. Comparisons were made between the linear poly(silyl ester)s and the crosslinked poly(silyl ester)s. After the crosslinking, the important resonance signal for ethenylene (CC) disappeared, and this showed that the crosslinking reaction was carried out progressively. The glass‐transition temperatures of the crosslinked poly(silyl ester)s were higher than those of the uncross‐ linked poly(silyl ester)s, and the thermal stability of the crosslinked poly(silyl ester)s was better than that of uncrosslinked poly(silyl ester)s. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1221–1225, 2007

Controlled release of paclitaxel from biodegradable unsaturated poly(ester amide)s/poly(ethylene glycol) diacrylate hydrogels

Biodegradable hydrogels (FPBe-G) were synthesized by the photopolymerization of two precursors: FPBe, a fumurate-based unsaturated poly(ester amide) (UPEA), and poly(ethylene glycol) diacrylate (PEG-DA). Depending on the feed ratio of these two precursors, the resultant FPBe-G hydrogels showed different crosslinking levels of network structure, mesh sizes (ξ) and matrix morphology. When a lipophilic drug, paclitaxel, was preloaded into FPBe-G hydrogels, the two-month drug-release kinetics from FPBe-G hydrogels in both pure PBS buffer and α-chymotrypsin media were measured. The paclitaxel-preloaded FPBe-G hydrogels in a α-chymotrypsin solution had significantly faster drug release rate than the corresponding hydrogels in a pure PBS buffer due to an enzyme catalyzed biodegradation of FPBe-G hydrogels. Sustained paclitaxel releases over a two-month period without initial burst release were also achieved by using hydrogels having certain feed ratios of hydrogel precursors. These paclitaxel release data correlated well with the molecular mesh size (ξ), molecular weight between cross-links (M c) and matrix morphological structure of FPBe-G hydrogels.

Preparation and characterization of unsaturated poly(ester‐imide) based on 1,4‐bis[2′‐trifluoromethyl‐4′‐(4″‐glycolformate)‐trimellitimidophenoxy]benzene

AbstractA novel diimidodialcohol monomer, 1,4‐bis[2′‐trifluoromethyl‐4′‐(4″‐glycolformate)‐ trimellitimidophenoxy]benzene (BGTB), was synthesized and characterized. It was reacted with isophthalic acid, maleic anhydride and propylene glycol to produce a novel unsaturated poly(ester‐imide) (BGTB‐UPEI) with imide and trifluoromethyl groups in the polymer backbone. The BGTB‐UPEI resin was diluted with reactive monomer (styrene) to give a low‐viscous poly(ester‐imide)/styrene (BGTB‐UPEI/St) mixed solution, which was then thermally cured to yield thermosetting BGTB‐UPEI/St composite. The effect of processing parameters such as the curing temperature and curing time, reactive monomer concentration and initiator amount on the curing reaction was systematically investigated. Experimental results indicated that the thermally cured BGTB‐UPEI/St composite exhibited much better thermal, mechanical, electrical insulating properties and chemical resistance than the standard unsaturated polyester/polystyrene composite. Copyright © 2006 Society of Chemical Industry

Preparation and characterization of a novel thermally stable unsaturated poly(ester-imide) based on 1,4-bis[2′-trifluoromethyl-4′-(4″-carboxylic acid)trimellitimido phenoxy]benzene

A novel thermally stable unsaturated poly(ester-imide) (UPEI-50) was prepared by thermal polycondensation of a diimidodicarboxylic acid monomer, 1,4-bis[2′-trifluoromethyl-4′-(4″-carboxylic acid)trimellitimido phenoxy]benzene (BTTB), maleic anhydride and 1,2-propylene glycol. The poly(ester-imide) resin obtained was found to be easily dissolved in glycidyl methacrylate (GMA) to give a homogeneous resin composition with low viscosity, which was then thermally cured into thermosetting poly(ester-imide)/glycidyl polymethacrylate polymer composite (UPEI-50/GMA). Effects of curing processing parameters such as the curing temperature and curing time, the reactive monomer concentration and the initiator amount etc. on curing reaction were systematically investigated. Experimental results indicated that the thermally cured UPEI-50/GMA polymer composite exhibited outstanding thermal stability, mechanical and electrical insulating properties.

Flame Retardant Unsaturated Poly(Ester Amide) Resins Based on Epoxy Resins

ABSTRACT Novel flame retardant unsaturated poly(ester amide) resins (FR-UPEAs) were prepared by the reaction of brominated epoxy resins (BER) with unsaturated aliphatic bisamic acids using a base catalyst. These FR-UPEAs were characterized by elemental analysis and number average molecular weight determination by non-aqueous conductometric titrations. The curing of these FR-UPEAs was carried out by using benzoyl peroxide (BPO) as a catalyst and was monitored on a differential scanning calorimeter (DSC). Based on DSC data, the glass fiber reinforced composites (i.e., laminates) of these FR-UPEAs have been fabricated and their chemical, mechanical, and electrical properties have been evaluated. The composites were analyzed for their self-extinguishing time. The unreinforced cured samples of FR-UPEAs resins were analyzed thermogravimetrically.

Synthesis and characterization of novel biodegradable unsaturated poly(ester amide)/poly(ethylene glycol) diacrylate hydrogels

AbstractA series of novel biodegradable hydrogels were designed and synthesized from four types of unsaturated poly(ester amide) (UPEA) and poly(ethylene glycol) diacrylate (PEG‐DA) precursors by UV photocrosslinking. These newly synthesized biodegradable UPEA/PEG‐DA hydrogels were characterized by their gel fraction (Gf), equilibrium swelling ratio (Qeq), compressive modulus, and interior morphology. The effect of the precursor feed ratio (UPEAs to PEG‐DA) on the properties of the hydrogels was also studied. The incorporation of UPEA polymers into the PEG‐DA hydrogels increased their hydrophobicity, crosslinking density (denser network), and mechanical strength (higher compressive modulus) but reduced Qeq. When different types of UPEA precursors were coupled with PEG‐DA at the same feed ratio (20 wt %), the resulting hydrogels had similar Qeq values and porous three‐dimensional interior morphologies but different Gf and compressive modulus values. These differences in the hydrogel properties were correlated to the chemical structures of the UPEA precursors; that is, the different locations of the >CC< double bonds in individual UPEA segments resulted in their different reactivities toward PEG‐DA to form hydrogels. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3932–3944, 2005

Synthesis and characterization of novel biodegradable unsaturated poly(ester amide)s

AbstractA series of novel biodegradable unsaturated poly(ester amide)s (UPEAs) were synthesized through the solution polycondensation of two unsaturated monomers, di‐p‐nitrophenyl fumarate and L‐phenylalanine 2‐butene‐1,4‐diol diester p‐toluene sulfonate, and four other saturated monomers in different combinations. The UPEAs were obtained in fairly good yields with N,N‐dimethylacetamide (DMA) as the solvent. The number‐average and weight‐average molecular weights of the UPEAs, measured by gel permeation chromatography, ranged from 10 to 30 kg/mol, they had a rather narrow molecular weight distribution of 1.40. The chemical structures of the novel biodegradable UPEAs were confirmed by both IR and NMR spectra. The UPEAs had higher glass‐transition temperatures than saturated PEAs of similar structures, and their glass‐transition temperatures were affected more by the CC double bond located in the diamide part than by those in the diester part. The solubility of the polymers was poor in water but better in DMA and dimethyl sulfoxide. With the availability of these inherent CC double bonds in the UPEA backbones, these UPEAs have the functionality of CC bonds, such as photochemical reactivity or the ability to react with or be modified by other bioactive or other environmentally sensitive compounds, and this can easily extend their applications to biomedical and pharmaceutical areas. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1463–1477, 2005

Interacting Blends of Novel Unsaturated Polyester Amide Resin with Methyl Methacrylate

Novel unsaturated poly (ester-amide) resins (UPEAs) were prepared by the reaction between an epoxy resin, namely diglycidyl ether of bisphenol–A (DGEBA) and unsaturated aliphatic bisamic acids, using a base catalyst. These UPEAs were then blended with a vinyl monomer namely, methyl methacrylate (MMA) to produce a homogeneous resin syrup. The curing of these UPEAs-MMA resin blends was carried out by using benzoyl peroxide (BPO) as a catalyst and was monitored by using a differential scanning calorimeter (DSC). The glass fibre reinforced composites (i.e. laminates) of this UPEA-MMA resin blends were fabricated using the DSC data. The chemical, mechanical and electrical properties of the glass fibre composites have also been evaluated. The unreinforced cured samples of the UPEA-MMA resin blends were also analysed by thermogravimetry (TGA).

Biodegradable polymeric bone cement formed from hydroxyapatite, poly (propylene fumerate), poly (vinyl pyrrolidone) and benzoyl peroxide

Polymeric cement is a new biocement material that is able to give immediate support to the implant area by inducing bone repair and a regeneration process through appropriate biodegradation processes. The aim of this study is to produce a polymeric cement using hydroxyapatite as absorbable filler, unsaturated polyester poly (propylene fumarate), poly (vinyl pyrrolidone) and benzoyl peroxide. The presence of hydroxyapatite is believed to enhance bioactivity. The hydroxyapatite powder used in this study was synthesised via precipitation, while poly (propylene fumarate) was synthesised using a direct esterification method. The cement was prepared, cast to form cylindrical specimens and subjected to compression testing. The crosslinking effect is achieved through the action of a mixture of poly (vinyl pyrrollidone) and benzoyl peroxide, which acted as initiator. Cement specimens were aged under simulated physiological conditions. The products were characterised using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was shown that the incorporation of bioceramic particles in biodegradable polymers rendered the cement bioactive and able to induce the formation of bonelike apatite on its surface.