超支化聚磷酸酯改性PP的研究

以新型的超支化聚磷酸酯(HPPE)对聚丙烯(PP)进行共混改性,研究了HPPE的用量和分子量对PP/HPPE复合材料性能的影响,还通过扫描电子显微镜(SEM)观察其试样冲击断面的微观形态并研究其增韧机理.结果表明,HPPE对PP/HPPE复合材料的冲击强度影响明显,当HPPE-1用量为3份时冲击强度可提高143.56%;熔体流动速率也有提高,但拉伸强度、弯曲强度和维卡软化点温度有微小下降,其增韧机理为两相"海-岛"结构增韧.     

Toughness and strength improvement of diglycidyl ether of bisphenol‐A by low viscosity liquid hyperbranched epoxy resin

This article reports on the use of low viscosity liquid thermosetting hyperbranched poly(trimellitic anhydride‐diethylene glycol) ester epoxy resin (HTDE) as an additive to an epoxy amine resin system. Four kinds of variety molecular weight and epoxy equivalent weight HTDE as modifiers in the diglycidyl ether of bisphenol‐A (DGEBA) amine systems are discussed in detail. It has been shown that the content and molecular weight of HTDE have important effect on the performance of the cured system, and the performance of the HTDE/DGEBA blends has been maximum with the increase of content and molecular weight or generation of HTDE. The impact strength and fracture toughness of the cured systems with 9 wt % second generation of HTDE are 58.2 kJ/m² and 3.20 MPa m^1/2, which are almost three and two times, respectively, of DGEBA performance. Furthermore, the tensile and flexural strength can be enhanced about 20%. The glass transition temperature and Vicat temperature, however, are found to decrease to some extent. The fracture surfaces are evaluated by using scanning electron microscopy, which showed that the homogeneous phase structure of the HTDE blends facilitates an enhanced interaction with the polymer matrix to achieve excellent toughness and strength enhancement of the cured systems, and the “protonema” phenomenon in SEM has been explained by in situ reinforcing and toughening mechanism and molecular simulation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2504–2511, 2006     

Toughness and reinforcement of diglycidyl ether of bisphenol-A by hyperbranched poly(trimellitic anhydride-butanediol glycol) ester epoxy resin

Hyperbranched epoxy resin shows best comprehensive performance in epoxy resin system and is considered as a kind of toughness and reinforcement additive. This article reports on the use of novel hyperbranched poly(trimellitic anhydride-butanediol glycol) ester epoxy resin (HTBE) prepared by us as a functional additive to an epoxy amine resin system. The effect of molecular weight and content of the HTBE on the performance of the diglycidyl ether of bisphenol-A (DGEBA)/HTBE hybrid resin are discussed in detail, and their performance has maximum with the increase of content and molecular weight of HTBE. The impact strength and fracture toughness of the hybrid resin containing 9 wt% second generation of HTBE are 48.2 kJ/m² and 2.71 MPa m^1/2, and which almost are 2.77 and 1.5 times of DGEBA performance respectively. Furthermore, the tensile and flexural strength can also be enhanced about 17%. The fracture surface micrograph of hybrid resin shows no microphase separation of the HTBE/DGEBA blends that facilitates an enhanced interaction to achieve excellent toughness and strength enhancement of the cured systems by scanning electron microscope (SEM). A novel situ reinforcing and toughening mechanism and model are discovered and confirmed by SEM, molecular simulation, and dynamic mechanical thermal analysis technology. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Preparation and properties of polydimethylsiloxane‐modified epoxy resins

In this work, polydimethylsiloxane (PDMS) with different molecular weight were used to modify diglycidyl ether of bisphenol A (DGEBA). A PDMS‐block‐DGEBA copolymer that acted as a compatibilizer was prepared via DGEBA, hydroxy terminated PDMS, and silane coupling agent in the presence of a catalyst. The reaction mechanisms and compatibilizing effects of the block copolymer were studied by means of Fourier transform infrared (FTIR) spectrum analysis and observation under scanning electron microscopy (SEM). The thermal and mechanical behaviors were analyzed as well. Results indicated that the block copolymer has good compatibilizing effect, and PDMS with low molecular weight could be dispersed in the DGEBA matrix more evenly. Moreover, the PDMS modified DGEBA systems had higher impact strength and lower weight loss rate than those of the pristine DGEBA system. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1683–1690, 2000     

Synthesis and performance of a novel nitrogen‐containing cyclic phosphate for intumescent flame retardant and its application in epoxy resin

A novel nitrogen‐containing cyclic phosphate (NDP) was synthesized and well characterized by ¹H, ¹³C, ³¹P NMR, mass spectra and elemental analysis. NDP was used as an additive intumescent flame retardant (AIFR) to impart flame retardancy and dripping resistance for diglycidyl ether of bisphenol‐A epoxy resin (DGEBA) curied by 4,4′‐diaminodiphenylsulfone (DDS) with different phosphorus content. The flammability, thermal stability, and mechanical properties of NDP modified DGEBA/DDS thermosets were investigated by UL‐94 vertical burning test, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and Izod impact strength and flexural property tests. The results showed that NDP modified DGEBA/DDS thermosets exhibited excellent flame retardancy, moderate changes in glass transition temperature and thermal stability. When the phosphorus content reached only 1.5 wt %, the NDP modified DGEBA/DDS thermoset could result in satisfied flame retardancy (UL‐94, V‐0). The TGA curves under nitrogen and air atmosphere suggested that NDP had good ability of char formation, and there existed a distinct synergistic effect between phosphorus and nitrogen. The flame retardant mechanism was further realized by studying the structure and morphology of char residues using FT‐IR and scanning electron microscopy (SEM). It indicated that NDP as phosphorus‐nitrogen containing flame retardant worked by both of the condensed phase action and the vapor phase action. Additionally, the addition of NDP decreased slightly the flexural strength of the flame retarded DGEBA epoxy resins, and increased the Izod impact strength of these thermosets. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41859.     

The synthesis and characterization of a novel phosphorus–nitrogen containing flame retardant and its application in epoxy resins

A novel, halogen‐free, phosphorus–nitrogen containing flame retardant 2[4‐(2,4,6‐Tris{4‐[(5,5‐dimethyl‐2‐oxo‐2λ⁵‐[1,3,2]dioxaphosphinan‐2‐yl)hydroxymethyl]phenoxy}‐(1,3,5)‐triazine (TNTP) was successfully synthesized in a three‐step process, and characterized by FTIR, NMR spectroscopy, mass spectra, and elemental analysis. A series of modified DGEBA epoxy resin with different loadings of TNTP were prepared and cured by 4,4‐diaminodiphenylsulfone (DDS). Thermal gravimetric analysis and vertical burning test (UL‐94) were used to evaluate the flame retardancy of TNTP on DGEBA epoxy resin. The results showed that TNTP had a great impact on flame retardancy. All modified thermosets by using TNTP exhibited higher T_g than pure DGEBA/DDS. The loading of TNTP at only 5.0 wt % could result in satisfied flame retardancy (UL‐94, V‐0) together with high char residue (27.3%) at 700°C. The addition of TNTP could dramatically enhance the flame retardancy of DGEBA epoxy resins, which was further confirmed by the analysis of the char residues by scanning electron microscopy and FTIR. Furthermore, no obviously negative effect was found on the Izod impact strength and flexural property of DGEBA epoxy resins when TNTP loading limited in 5.0 wt %. DGEBA/DDS containing 2.5 wt % TNTP could enhance Izod impact strength from 10.47 to 10.94 kJ m^?2, and showed no appreciable effect on the flexural property (85.20 MPa) comparing with pure DGEBA/DDS (87.03 MPa). Results indicated that TNTP as a phosphorus–nitrogen synergistic intumescent flame retardant could be used for DGEBA epoxy resin. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41079.     

Preparation of hyperbranched epoxy resin containing nitrogen heterocycle and its toughened and reinforced composites

Low‐viscosity hyperbranched epoxy resin‐containing nitrogen heterocycle (HTPE) is synthesized from epichlorohydrin (ECH), dimethylol propionic acid (DMPA), and tris(2‐hydrooxyethyl)‐isocyanurate. The structure and properties of HTPE are characterized by FTIR, GPC, and molecular simulation. The performance of HTPE/diglycidyl ether of bisphenol‐A (DGEBA) composites first increase and then decrease with the increase of the content and molecular weight of HTPE. Compared to those of pure DGEBA, the impact strength, fracture toughness, tensile, and flexural strength of HTPE‐2/DGEBA composite can be enhanced by about 192%, 39%, 18%, and 23%, respectively. The absence of microphase separation and the presence of lots of “protonema” on the fracture surface of the composites are explicated by an in situ reinforcing and toughening mechanism. The intramolecular cavity of HTPE and the strong interaction between HTPE and DGEBA are two key factors to toughening and reinforcing DGEBA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Hyperbranched polysiloxane‐based diglycidyl ether of bisphenol a epoxy composite for low k dielectric application

A new type of diglycidyl ether of bisphenol A (DGEBA) epoxy‐based hybrids has been developed by the incorporation of varying percentages of glycidyl‐terminated hyperbranched polysiloxane (HPSiE) into DGEBA resin and are characterized for their physicochemical, thermal, mechanical, and dielectric behaviors by modern analytical techniques. Data resulted from different studies indicate that the incorporation of HPSiE into DGEBA epoxy resin significantly improved the impact strength, thermal, and dielectric properties with an increase in the HPSiE loading. The contact angle [water and diiodomethane (DI)] increase with increases according to the weight percentages of HPSiE, which indicates the HPSiE‐modified DGEBA shows hydrophobic in nature. The resulting epoxy‐based hybrid composites can be used effectively for different industrial and engineering applications for better performance with improved longevity. POLYM. COMPOS., 34:904–911, 2013. © 2013 Society of Plastics Engineers     

Synthesis and characterization of a new phosphorus‐containing furan‐based epoxy curing agent as a flame retardant

In this study, 5‐hydroxymethyl‐2‐furfural (HMF) was used as a renewable resource for preparing an epoxy curing agent (furan‐based flame retardant, FBF), and a phosphorus‐containing functional group was also incorporated to enhance the flame retardancy of FBF. FBF was easily synthesized, and the total yield was 83%. 2‐Methyl imidazole was chosen as an accelerant to reduce the activation energy for the reaction of FBF with diglycidyl ether of bisphenol A (DGEBA). The DGEBA cured with FBF showed a low glass transition temperature and cross‐linking density compared with those of DGEBA cured with isophorondiamine (IPDA) and 4,4′‐diaminodiphenylmethane (DDM). However, the FBF‐cured DGEBA exhibited a comparable tensile strength with that of the DGEBA‐IPDA and DGEBA‐DDM systems (81.96 MPa) and a significantly higher tensile modulus (1721 MPa) owing to the H‐bonding via oxygens of the phosphorus group of FBF in the network structure. The DGEBA cured with FBF showed a high char yield and a high limitation of oxygen index value (29.7%) compared with those of the IPDA‐ and DDM‐cured ones. The cone calorimeter measurement also showed that the DGEBA‐FBF system had a low heat release rate, total heat release, and smoke production rate, indicating the improved flame retardancy mediated by FBF.     

Curing and thermal behavior of epoxy resin in the presence of silicon‐containing amide amines

The article describes the synthesis and characterization of silicon‐containing amide amines obtained by the reaction of bis(4‐chlorobenzoyl)dimethylsilane with 4,4′‐diaminodiphenyl ether, 4,4′‐diaminodiphenyl methane, 4,4′‐diaminodiphenyl sulfone/3,3′‐diaminodiphenyl sulfone, bis(3‐aminophenyl)methyl phosphine oxide, and tris(3‐aminophenyl)phosphine oxide with dimethyl acetamide as a solvent. Structural characterization of amide amines was done with Fourier transform infrared and ¹H‐NMR spectroscopy. We used these aromatic amide amines as curing agents to investigate the effect of structure and molecular size on the curing and thermal behavior of diglycidyl ether of bisphenol A (DGEBA). The curing behavior of DGEBA in the presence of stoichiometric amounts of silicon‐containing aromatic amide amines was investigated by differential canning calorimetry. A broad exothermic transition in the temperature range of 200–300°C was observed in all the samples. The peak exotherm temperature was lowest in the case of phosphorus‐containing amides and was highest in the case of ether‐containing amides. Thermal stability of the isothermally cured resins was evaluated with dynamic thermogravimetry in a nitrogen atmosphere. A significant improvement in the char yield was observed with silicon‐containing amines, and it was highest in case of samples with both silicon and phosphorus as flame‐retarding elements. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1345–1353, 2003     

Toughening epoxy resins with solid acrylonitrile–butadiene rubber

The feasibility of using solid acrylonitrile–butadiene rubbers (NBR) with 19 and 33% w/w acrylonitrile to toughen diglycidyl ether of bisphenol A (DGEBA) epoxy resins has been investigated. Thermal analysis experiments revealed a two‐phase morphology of these rubber‐modified epoxies. However, the higher content of acrylonitrile in the rubber caused better compatibility between NBR and the epoxy resin. The rubber with 33% acrylonitrile was found to be an effective toughening agent for DGEBA epoxy resins. Fracture surface studies and also the high tensile strength of crosslinked high molecular weight NBR suggest that the toughening effect should arise from rubber bridging and tearing mechanisms. © 2000 Society of Chemical Industry     

Effect of core–shell zinc hydroxystannate nanoparticle–organic macromolecule composite flame retardant prepared by masterbatch method on flame‐retardant behavior and mechanical properties of flexible poly(vinyl chloride)

Macromolecule flame retardant melamine‐dicyandiamide‐formaldehyde‐phosphoric acid (denoted as MDFP) was used as the shell material to synthesize zinc hydroxystannate@MDFP (denoted as ZHS@MDFP), a novel composite flame retardant with core–shell structure, via masterbatch method. The morphology and structure of ZHS@MDFP were analyzed by means of transmission electron microscopy, X‐ray powder diffraction, Fourier transform infrared spectrometry, and thermal analysis. Moreover, the effect of ZHS@MDFP as a flame retardant on the flame‐retardant behavior and mechanical properties of flexible poly(vinyl chloride) (denoted as PVC) was investigated. It has been found that as‐synthesized ZHS@MDFP composite flame retardant has core–shell structure. Besides, as‐synthesized ZHS@MDFP as a core–shell flame retardant is superior to ZHS in increasing the limiting oxygen index and decreasing the smoke density rating of PVC, which is because the decomposition of MDFP shell as the blowing agent expands the char layer thereby improving the flame‐retarding capability of ZHS core. More importantly, ZHS@MDFP does not cause damage to the tensile strength and elongation at break of PVC matrix, which implies that the MDFP shell favors to improve the compatibility between ZHS and flexible PVC matrix. POLYM. ENG. SCI., 54:1983–1989, 2014. © 2013 Society of Plastics Engineers     

Study on the Performance of Diglycidyl Ether of Bisphenol-A/Hyperbranched Aromatic Polyester Epoxy Resin (HTME) System and Their Toughness Mechanism

This paper reports on the use of liquid hyperbranched aromatic polyester epoxy resin (HTME) as an additive to an epoxy resin/amine system. Four kinds of different molecular weight and epoxy equivalent weight HTME as modifiers in the diglycidyl ether of bisphenol-A (DGEBA) amine systems are discussed in detail. It was shown that the content and molecular weight of HTME have important effect on the performance of the cured system, and the performance of the HTME/DGEBA blends has maximum with the increase of content and molecular weight or generation of HTME. The impact strength and fracture toughness of the cured system with 9 wt.% second or three generation of HTME are almost 2.77 and 1.71 times, respectively, DGEBA performance; furthermore, the tensile and flexural strength can be enhanced about 17% and 20%, respectively. The glass transition temperature and Vicat temperature, however, are found to decrease to some extent. The scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), and molecular simulation technology are used to study the situ reinforcing and toughening mechanism. The three-dimensional size and structure shape of HTME-2 are displayed by molecular simulation technology.     

Joint flame‐retardant effect of triazine‐rich and triazine/phosphaphenanthrene compounds on epoxy resin thermoset

To obtain a more efficient flame‐retardant system, the extra‐triazine‐rich compound melamine cyanurate (MCA) was coworked with tri(3‐9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide‐2‐hydroxypropan‐1‐yl)?1,3,5‐triazine‐2,4,6‐trione (TGIC–DOPO) in epoxy thermosets; these were composed of diglycidyl ether of bisphenol A (DGEBA) epoxy resin and 4,4′‐diaminodiphenyl methane (DDM). The flame‐retardant properties were investigated by limited oxygen index measurement, vertical burning testing, and cone calorimeter testing. In contrast to the DGEBA/DDM (EP for short) thermoset with a single TGIC–DOPO, a better flame retardancy was obtained with TGIC–DOPO/MCA/EP. The 3% TGIC–DOPO/2% MCA/EP thermoset showed a lower peak heat‐release rate value, a lower effective heat of combustion value, fewer total smoke products, and lower total yields of carbon monoxide and carbon dioxide in comparison with 3% TGIC–DOPO/EP. The results reveal that MCA and TGIC–DOPO worked jointly in flame‐retardant thermosets. The dilution effect of MCA, the quenching effect of TGIC–DOPO, and their joint action inhibited the combustion intensity and imposed a better flame‐retardant effect in the gas phase. The 3% TGIC–DOPO/2% MCA/EP thermoset also exhibited an increased residue yield, and more compositions with triazine rings were locked in the residues; this implied that MCA/TGIC–DOPO worked jointly in the condensed phase and promoted thermoset charring. The results reveal the better flame‐retardant effect of the MCA/TGIC–DOPO system in the condensed phase. Therefore, the joint incorporation of MCA and TGIC–DOPO into the EP thermosets increased the flame‐retardant effects in both the condensed and gas phases during combustion. This implied that the adjustment to the group ratio in the flame‐retardant group system endowed the EP thermoset with better flame retardancy. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43241.     

Novel synergistic flame‐retardant system of Mg–Al–Co–LDHs/DPCPB for ABS resins

Acrylonitrile‐butadiene‐styrene (ABS) resins are widely used in many sectors of the industry due to excellent mechanical properties, low temperature resistance, heat resistance, and chemical resistance. However, its flammability constitutes a key limitation in their applications. Consequently, development of flame‐retarding ABS resins is imperative. Herein, we report a novel synergistic system composed of Mg–Al–Co–layered double hydroxides (LDHs) prepared via a co‐precipitation method, and [4‐(diphenoxy‐phosphorylamino)‐6‐phenyl‐[l,3,5] triazin‐2‐y1]‐phosphoramidic acid diphenyl ester (DPCPB), a novel intumescent flame retardant. The properties of the as‐prepared LDHs/DPCPB/ABS composites are evaluated using standard combustion performance tests including limiting oxygen index (LOI) and vertical burning test (UL‐94). Novel ABS resins with the composition of ABS/DPCPB = 100/25 and ABS/DPCPB/LDHs = 100/2l/4 exhibit higher LOIs, 23.9 and 24.7, respectively, compared to 18.1 for the pure ABS. Meanwhile, they meet the V‐2 and A‐1 level, respectively, in UL‐94 tests. Moreover, the prepared composites exert flame‐retarding effects in gas phase and condensed phase simultaneously. Our results reveal synergistic effects between Mg–Al–Co–LDHs and DPCPB for the flame retardation of ABS resins. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46319.     

新型脂肪族超支化环氧树脂的制备及其改性作用

采用一步法合成了新型脂肪族超支化环氧树脂HTPE-3,利用FT-IR对其结构进行了表征。研究了双酚A型环氧树脂E-51/HTPE-3杂化树脂的力学性能和热性能。结果显示,杂化树脂的韧性和强度随HTPE-3含量的增加先增加后降低,具有极大值;当HTPE-3质量分数为12%左右时,与纯E-51树脂相比,杂化树脂的冲击强度和断裂韧性分别提高了169.8%和35.2%,拉伸强度和弯曲强度分别提高了6.5%,10.0%,维卡软化点温度、玻璃化转变温度和热分解温度略有下降。     

Flame‐Retarded Epoxy Resins with a Curing Agent of DOPO‐Triazine Based Anhydride

A 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO)‐triazine based anhydride (2,4,6‐tris‐(DOPO‐methylformatephthalic anhydride‐phenoxy)‐1,3,5‐triazine (TDA)) is synthesized and used as a halogen‐free flame retardant co‐curing agent for diglycidyl ether of bisphenol A/methylhexahydrophthalic anhydride (DGEBA/MHHPA) system. The conjugation of anhydride group is increased by the utilization of TDA, leading to the reduction in the curing activation energy. The cured epoxy resin passes V‐0 rating of UL 94 test with the limiting oxygen index of 32.7 vol% when the phosphorus content is only 1.5 wt%. The flame‐retarding action of triazine ring and DOPO moiety is investigated by the residue analysis and the characterization of pyrolysis gas. Due to the presence of bulky aromatic subunits in the molecular structure of TDA, the flame‐retarded epoxy resins maintain the high glass transition temperature of DGEBA/MHHPA. Besides, the moisture absorption is diminished following the usage of TDA.

     

Synergistic barrier flame‐retardant effect of aluminium poly‐hexamethylenephosphinate and bisphenol‐A bis(diphenyl phosphate) in epoxy resin

Two flame retardants, aluminium poly‐hexamethylenephosphinate (APHP) and bisphenol‐A bis(diphenyl phosphate) (BDP), were incorporated into diglycidyl ether of bisphenol A (DGEBA) thermoset with 4,4′‐diaminodiphenyl sulfone (DDS) as curing agent, and then the synergistic flame‐retardant behaviors of the cured thermosets were investigated. Compared with thermosets containing 10 wt% APHP and 10 wt% BDP alone, the sample with 3.3 wt% APHP and 6.7 wt% BDP (3.3%APHP/6.7%BDP/EP; EP is DGEBA/DDS) possessed a better flame‐retardant effect since its limited oxygen index reached 35.0% and in the UL94 test it passed the V‐0 rating. The cone calorimeter test revealed that the 3.3%APHP/6.7%BDP/EP sample generated less gaseous fragments and more smoke particles instead of fuels and verified that APHP and BDP exhibited an outstanding synergistic effect on the barrier effect. Macroscopic digital photos and micrographs from scanning electron microscopy further disclose that BDP facilitated the formation of a flexible film covering holes in the residue. The flexible film was combined with aluminium phosphate particles which were produced by decomposed APHP, thereby forming a char layer with increased barrier effect. The synergistic barrier effect from APHP and BDP imposed a better flame‐retardant performance for epoxy thermosets. © 2017 Society of Chemical Industry     

High performance modification of hyperbranched polyborate on diglycidyl ether of bisphenol‐a resin

High performance epoxy resin was obtained by introducing hyperbranched polyborate (HBPB) into diglycidyl ether of bisphenol A (DGEBA) resin to overcome the defects such as low char yield and poor toughness of DGEBA resin. By virtue of the massive functional end groups, hyperbranched and rigid boron‐containing structures of HBPB, the thermal resistance of DGEBA resin cured with diamino diphenyl sulfone (DDS) can be greatly improved. Moreover, with the toughening effect of hyperbranched structures of HBPB, the mechanical properties such as flexural strength and interlaminar shear strength of the carbon fiber reinforced DGEBA‐DDS composite could be greatly increased by HBPB without a decrease on modulus and glass transition temperature of DGEBA‐DDS resin. POLYM. COMPOS. 36:424–432, 2015. © 2014 Society of Plastics Engineers     

Fracture and adhesion behaviors of epoxy resins modified with poly(amine‐quinone)

An amine‐quinone monomer, i.e. 2,5‐bis(4,4′‐methylenedianiline)‐1,4‐benzoquinone (BB), was synthesized by the Michael addition of 4,4′‐diaminodiphenyl methane with 1,4‐benzoquinone. To evaluate the effect of BB content on the glass transition temperature (T_g) and crosslinking density (ρ) of cured diglycidyl ether of bisphenol A (DGEBA)/BB systems, storage modulus and loss factor measurements were obtained using dynamic mechanical analysis. The mechanical properties of the systems were determined in terms of the fracture toughness, impact strength, and adhesion strength. As a result, the ρ values of the systems were found to decrease systematically as the BB content increased. The fracture toughness and adhesion strength of the systems increased with increasing BB content. These results indicate that the addition of BB into epoxy resins increases the free volume of the epoxy network and absorbs the deformation energy, resulting in an improvement of the mechanical properties of the DGEBA/BB systems. Copyright © 2006 Society of Chemical Industry