View PDF VersionPrevious Article
 
DOI: 10.1039/C5RA10255C (Paper) RSC Adv., 2015, 5, 59804-59811

The dependence of the non-linear creep properties of TATB-based polymer bonded explosives on the molecular structure of the polymer binder: (II) effects of the comonomer ratio in fluoropolymers

Congmei Lin, Shijun Liu, Zhong Huang, Guansong He, Feiyan Gong, Yonggang Liu and Jiahui Liu*
Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang, Sichuan 621900, P. R. China. E-mail: huiihuii@163.com; Fax: +86-816-2495856; Tel: +86-816-2482005

Received 30th May 2015 , Accepted 3rd July 2015

First published on 3rd July 2015

Abstract

1,3,5-triamino-2,4,6-trinitrobenzene (TATB) based polymer bonded explosives (PBXs), with three polymer binders containing different molecular structures, were studied by non-linear time dependent creep tests at different temperatures and stresses. Three fluoropolymers, i.e. F2311, F2313, and F2314 with molar ratios of comonomer vinylidene fluoride (VDF) and chlorotrifluoroethylene (CTFE) of 1[thin space (1/6-em)]:[thin space (1/6-em)]1, 1[thin space (1/6-em)]:[thin space (1/6-em)]3, and 1[thin space (1/6-em)]:[thin space (1/6-em)]4 were chosen as polymer binders. The experimental results suggested that all of the materials showed temperature, stress and molecular structure sensitivity. With the decrease of temperature and stress, the creep resistance of the three TATB-based PBXs was improved with reduced creep strain, decreased steady-state creep strain rate, and prolonged creep failure time. Replacement of F2311 with F2313 in the binder system lead to a creep strain decrease and creep failure time rise. With further increasing of the CTFE content in fluoropolymers from 75% to 80%, the creep resistance performances were enhanced for TATB/F2314 composites under pressures from 1 to 9 MPa, compared with TATB/F2313 composites. The creep strain–time plots for TATB-based PBXs could be accurately fit using the six-element mechanical model. The long-term creep behaviors of TATB-based PBXs were predicted based on the time-temperature superposition (TTS) concept. In addition, the dynamic behaviors and mechanical properties of fluoropolymers and TATB-based PBXs were also studied and analyzed in detail.

1. Introduction

Polymer bonded explosives (PBXs) based on explosive crystals and polymer binder are widely used in many defense and industrial fields.1–3 Generally, PBXs are comprised of 90–95% weight of explosive crystals and 5–10% weight of polymeric binders.4 It is now well accepted that although the ratio of the polymer binder component is limited to a low value, the component and proportion of the polymer binder has a marked influence on the properties of PBX, such as thermal decomposition behaviors, mechanical properties, failure form, aging resistance, and sensitivity.5–10

As a typical representative, fluoropolymer is one kind of the most commonly used binders with the advantages of good physical and chemical stability, excellent aging resistance and heat resistance, and great compatibility with other components in composite explosives.11–15 Several PBX materials have been formulated with fluoropolymer as a binder in the last decades, such as LX-17 (92.5% 1,3,5-triamino-2,4,6-trinitrobenzene TATB and 7.5% fluoropolymer kel-F800 by weight) and PBX-9502 (95% TATB and 5% kel-F800 by weight).16–18 There are many reports on the experiment and simulation study of fluoropolymer and its PBXs. Bourne et al.19 presents experimental data on equation-of-state and shock-induced damage evolution of the fluoropolymer Kel-F800. It is revealed that Kel-F800 shows decreasing spall strength with increasing stress. Gustavsen et al.17 have conducted a series of shock initiation experiments on PBX 9502 cooled to −55 °C. It is found that wave profiles from embedded gauges are qualitatively similar to those observed at 23 °C. However, at −55 °C, PBX 9502 is much less sensitive than at 23 °C. Zhang et al.20 have reported the aggregate behaviors of fluoropolymers F2311, F2312, F2313 and F2314 in TATB-based PBX with the dissipative particle dynamics method. The self-aggregate behaviors and the poor wrap property of fluoropolymers in the TATB-based PBX are consistent with the experimental observation. The ‘insert’ model for β-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)-based PBX has been proposed to study the mechanical properties of HMX/F2311 PBX. It is revealed that the rigidity is weakened and the ductility is improved by adding a small amount of F2311 in the crystalline HMX.21 Similar results that the ductility of crystalline TATB can be effectively improved by blending fluorine-containing polymers in small amounts have been found using molecular dynamics simulations.22

It is recognized that despite the polymer content being very low, the creep property of the polymer is the main factor in influencing the creep damage properties of PBX.23 However, few reports have been found with respect to the influences of molecular structure of the polymer binder on the creep performance of PBX.24,25 In our previous wok, the studies on the effects of the comonomer type of fluoropolymers on the three-point bending creep behaviors of TATB-based PBXs have been conducted.26 The experimental results show that compared with a copolymer of VDF and CTFE, the incorporation of tetrafluoroethylene and hexafluoropropylene comonomers in fluoropolymer results in a decrease of the steady-state creep strain rate and the maximal creep strain values and an increase of creep rupture time for TATB-based PBXs.

In order to make clear the effects of molecular structure of polymer binder on the non-linear viscoelastic properties of PBX, in this work, creep characterization tests were performed for TATB-based PBXs with three fluoropolymers containing different comonomer ratios (including F2311, F2313, and F2314). Moreover, the dynamic and static mechanical properties and morphologies of the composites were investigated and discussed to understand the relative mechanisms.

2. Experimental section

2.1 Materials

TATB was supplied by Institute of Chemical Materials, CAEP, China. Three fluoropolymers (F2311, F2313, and F2314) with the molecular structures of –[–(–CF2–CH2–)a–(–CF2–CFCl–)b–]n– were provided by Zhonghao Chenguang Chemical Industry Co., Ltd China. The molar ratios (a[thin space (1/6-em)]:[thin space (1/6-em)]b) of comonomer vinylidene fluoride (VDF) and chlorotrifluoroethylene (CTFE) in F2311, F2313, and F2314 were 1[thin space (1/6-em)]:[thin space (1/6-em)]1, 1[thin space (1/6-em)]:[thin space (1/6-em)]3, and 1[thin space (1/6-em)]:[thin space (1/6-em)]4, respectively.

2.2 Fabrication of TATB-based PBXs

Three formulations which contained TATB as explosive crystal and copolymer of VDF and CTFE as polymer matrix were designed. TATB-based PBXs with F2311, F2313, and F2314 as polymer binder were labeled as PBX-1, PBX-2, and PBX-3, respectively. The molding powder of TATB-based PBXs was prepared with water suspension methods. Afterwards, the molding powder product was pressed in a mould and transformed into explosive pellets.

2.3 Characterizations

Dynamic mechanical analysis (DMA) was conducted with a dynamic mechanical analyzer (DMA 242C, NETZSCH, Germany) in a three-point bending mode with specimens' dimensions of 30.0 mm long × 10.0 mm wide × 1.5 mm thick. The tests were performed at 1 Hz with a constant heating rate of 1 °C min−1 ranging from −50 to 100 °C.

All static mechanical properties were examined by a universal testing machine (5582, INSTRON, USA). At least three specimens of each composite were tested, and the average values were reported.

The morphologies and structures of the fracture surface of various TATB-based formulations were identified by a CamScan Apollo 300 (UK) scanning electron microscopy (SEM).

A Netzsch DMA 242C instrument was also used to detect the short-term (less than 5400 s) creep behaviors of various TATB-based PBXs in a three-point bending mode under different temperatures and stresses.

3. Results and discussion

3.1 Characterization of various fluoropolymers

The viscoelastic properties of the materials, including the information of storage modulus and loss factor (tan[thin space (1/6-em)]delta) of polymers within the measured temperature range could be characterized by dynamic mechanical analysis.27 Fig. 1 shows the storage modulus and loss factor curves of three fluoropolymers with different VDF/CTFE molar ratios. It is found that the storage modulus of fluoropolymers reduce with increasing temperature. Due to the symmetrical substitution on the quaternary carbon for polyvinylidene fluoride (PVDF), the barrier to internal rotation of polymer main chain is low with good chain flexibility and the glass transition of PVDF is visible at about −30 °C.28 Compared with PVDF, the substituent groups are manifolded and the glass transition temperature of polychlorotrifluoroethylene (PCTFE) investigated by Khanna29 is reported to be 75 °C. As expected, an improvement in the glass transition temperature of fluoropolymers is also obtained by the decreased VDF/CTFE molar ratio. Consequently, F2311, F2313, and F2314 have the glass transition temperatures of 12.6 °C, 44.2 °C, and 55.2 °C, respectively.
image file: c5ra10255c-f1.tif
Fig. 1 Dynamic mechanical properties for fluoropolymers with different comonomer ratio: (a) storage modulus (E′), (b) loss factor (tan[thin space (1/6-em)]δ).

The tensile properties of three fluoropolymers at room temperature have been determined and listed in Table 1. The results indicate that the tensile strength increases with the decrease of VDF/CTFE molar ratio in fluoropolymers. Compared with F2311, the tensile strengths of F2313 and F2314 are increased by 324.8% and 398.8%.

Table 1 Tensile properties of three fluoropolymers
sample F2311 F2313 F2314
Tensile strength/MPa 4.19 17.8 20.9
Elongation at break/% 1338.0 325.6 211.0

3.2 Dynamic and static mechanical properties

Dynamic mechanical properties of TATB-based PBXs are reported in Fig. 2. All composites exhibit a decreased storage modulus with increasing temperature. It can be also seen from Fig. 2 that the molecular structure of polymer binder has obvious effects on the PBX's dynamic mechanical properties. The expected improvement in the storage modulus derived from the replacement of F2311 with F2313 and F2314 as polymer matrices is observed. An inflexion or a peak value, corresponding to the Tg of corresponding polymer binders, exists in the loss factor curves for the TATB-based PBXs. The PBXs becomes soft above this temperature, leading to a sharp drop of storage modulus.
image file: c5ra10255c-f2.tif
Fig. 2 Dynamic mechanical properties of TATB-based PBXs: (a) storage modulus (E′), (b) loss factor (tan[thin space (1/6-em)]δ).

The compressive and tensile mechanical properties were measured using the compressive and Brazilian tests on a circular cylinder with 20 mm in diameter by 6–20 mm in height. A description of the method and equipment of Brazilian tests is given elsewhere.30 Table 2 shows the representative resulting mechanical properties of three TATB-based PBXs at room temperature.

Table 2 Comparison of mechanical properties for three explosives
Sample Compressive strength/MPa Compressive elongation at break/% Tensile strength/MPa Tensile elongation at break/%
PBX-1 14.23 3.85 3.20 1.04
PBX-2 24.27 3.09 4.32 0.369
PBX-3 25.81 1.96 4.76 0.143

It can be found from Table 2 that the molecular structure of polymer binder also markedly affects the static mechanical behaviors of the TATB-based PBXs. Compared with PBX-1, a pronounced increase of strength can be noticed for PBX-2 and PBX-3 at room temperature.

3.3 Morphology analysis

The SEM micrographs of the fracture surface for TATB-based PBXs with F2311, F2313, F2314 as polymer binders which are obtained after dynamic mechanical measurements are shown in Fig. 3. It can be clearly seen that filamentous binder exists at the fracture surface of all PBXs, indicating that binder breakage is a kind of the main rupture mode. In addition, the amount of filamentous binder evidently increases with decreasing VDF/CTFE molar ratio.
image file: c5ra10255c-f3.tif
Fig. 3 SEM images of the fracture surface: (a) PBX-1, (b) PBX-2, (c) PBX-3.

3.4 Three-point bending creep behaviors of TATB-based PBXs

3.4.1 Stress dependence. The three-point bending creep tests are performed to characterize the creep response of TATB-based PBXs with different fluoropolymers at the stress levels of 1–9 MPa (60 °C). Fig. 4 shows typical creep data for three samples. The creep performance parameters of TATB-based PBXs, including steady-state creep strain rate, creep failure strain and creep failure time are summarized in Table 3. Clearly, the creep strain of TATB-based PBXs increases with the increase of stress level. The increase of applied stress from 1 MPa to 1.5 MPa of PBX-1 leads to the increase of creep strain in the whole time range. In the case of the more highly loaded material tests (2 MPa), the specimen fractures occur at 705 s. Similar change trends of creep behaviors with stress are also displayed in PBX-2 and PBX-3.
image file: c5ra10255c-f4.tif
Fig. 4 Stress dependent creep strain of TATB-based PBXs at 60 °C: (a) PBX-1; (b) PBX-2; (c) PBX-3.
Table 3 The creep performance parameters of TATB-based PBXs under different loading stresses at 60 °C
Sample Experimental conditions Steady-state creep strain rate/s−1 Creep rupture strain Creep rupture time/s
PBX-1 60 °C/1 MPa 9.237 × 10−9 >3.222 × 10−4 >5400
60 °C/1.5 MPa 2.653 × 10−8 >5.005 × 10−4 >5400
60 °C/2 MPa 3.818 × 10−7 7.015 × 10−4 705
PBX-2 60 °C/1 MPa 5.091 × 10−9 >2.532 × 10−4 >5400
60 °C/4 MPa 1.489 × 10−8 >7.108 × 10−4 >5400
60 °C/7 MPa 1.494 × 10−7 7.580 × 10−4 2115
60 °C/9 MPa 1.031 × 10−6 6.879 × 10−4 210
PBX-3 60 °C/1 MPa 1.601 × 10−9 >9.274 × 10−5 >5400
60 °C/4 MPa 1.397 × 10−8 >6.356 × 10−4 >5400
60 °C/7 MPa 5.152 × 10−8 1.020 × 10−3 4155
60 °C/9 MPa 6.022 × 10−7 7.423 × 10−4 660

It is evident from Fig. 4 and Table 3 that the molar ratio of comonomer VDF and CTFE in fluoropolymers has a significant impact on the creep response of TATB-based PBXs. The application of F2313 in PBX-2 results in an 44.9% steady-state creep strain rate and 21.4% maximal creep strain at 5400 s decrease as compared to F2311 in PBX-1, when a stress of 1 MPa is used at 60 °C. As it is shown, no creep fracture occurs up to 7 MPa for PBX-2, while creep fracture occurs at 705 s under 2 MPa for PBX-1. With regard to PBX-3, the application of F2314 binder leads to a further increase of creep resistance. For example, it is found that the steady-state creep strain rate and the creep rupture time of the PBX-3 at 60 °C/7 MPa are 5.152 × 10−8 s−1 and 4155 s. With respect to the composite PBX-2 that contains F2313 binder, the steady-state creep strain rate is reduced by 65.5% and the creep rupture time is increased by 96.5%. Such an obvious rise in creep resistance could be attributed to the higher mechanical strength and glass transition temperature with decreasing VDF/CTFE molar ratio. Compared with F2311, due to the restrained movement of molecular chains in polymer binders F2313 and F2314, the friction between F2313 and F2314 chains is enhanced and thus induces the increased creep resistance of PBX-2 and PBX-3.

3.4.2 Temperature dependence. The constant-stress, three-point bending creep tests are also performed at temperatures ranging from as low as 30 °C, up to 80 °C. In the tests, 1 MPa is carefully selected as the applied stress within the elastic range. The results are displayed in Fig. 5. As expected, the high temperature can bring large creep strain and accelerate the deformation of TATB-based PBXs because of the temperature-activated softening of the polymer matrix.31 The highest creep strain is observed for PBX-1, which is much higher than that for the PBX-2 and PBX-3 systems at all temperatures.
image file: c5ra10255c-f5.tif
Fig. 5 Temperature dependent creep strain of TATB-based PBXs under 1 MPa: (a) PBX-1; (b) PBX-2; (c) PBX-3.
3.4.3 Creep modeling and analysis. In order to understand the influences of comonomer ratio in fluoropolymers on the creep behaviors of TATB-based PBXs, the six-element mechanical model which is one of the most effective models with high precision is applied in this work. The six-element mechanical model is a combination of a Maxwell element and two Kelvin–Voigt elements.26 According to the model, the total strain of polymer composite material PBX is the sum of four essentially separate parts and could be determined by:
 
image file: c5ra10255c-t1.tif(1)
where ε(t) denotes a function of creep strain ε with creep time t, ε1 is the instantaneous elastic deformation, ε2 and ε3 are the high elastic deformation, ε4 is the viscous flow deformation, σ0 is the initial stress, E1 is the elastic modulus of instantaneous elastic deformation, E2 and E3 are the elastic modulus of high elastic deformation, τ2 and τ3 are the relaxation time, η4 is the bulk viscosity, respectively.

Fig. 6 shows the experimental and fitting curves of creep behaviors at various temperatures according to six-element mechanical model, and the six parameters (E1, E2, E3, τ2, τ3, and η4) are defined and summarized in Table 4. It can be clearly seen that the modeling curves show a satisfactory agreement with the experimental data of TATB-based PBXs. Results show that the E2, E3, and η4 of explosives have the same change trend whether for different type explosives or at different temperatures, which indicates they can be used to characterize the creep resistance of explosive material. The increased values of E2, E3, and η4 with decreasing temperature indicate the reinforced mechanical properties of the amorphous regions and increased resistance to viscous flow. Among the modeled six parameters (E1, E2, E3, τ2, τ3, and η4), the parameters E2 and E3 seem to increase with decreasing VDF/CTFE molar ratio in fluoropolymers. It can be attributed to the fact that the higher content of CTFE monomers in polymer binder leads to the blockage of molecular thermodynamic movement and an increase of the rigidity of material. In addition, due to the restricted relative slide of molecular chain, the values of η4 also increase with decreasing VDF/CTFE molar ratio in fluoropolymers.


image file: c5ra10255c-f6.tif
Fig. 6 Modeling results of creep strain curves of TATB-based PBXs under 1 MPa predicted by six-element mechanical model: (a) PBX-1; (b) PBX-2; (c) PBX-3.
Table 4 The simulated parameters of six-element model for TATB-based PBXs under different test conditions
Sample Test condition E1/MPa E2/MPa τ2/s E3/MPa τ3/s η4/MPa s
PBX-1 30 °C/1 MPa 4.394 × 105 4.328 × 104 554.30 1.241 × 104 14.41 3.483 × 108
45 °C/1 MPa 4.159 × 105 1.429 × 104 651.14 9.312 × 103 23.23 1.505 × 108
60 °C/1 MPa 1.200 × 107 9.558 × 103 649.35 5.674 × 103 42.99 1.248 × 108
80 °C/1 MPa 1.129 × 106 5.895 × 103 670.74 5.571 × 103 47.54 7.889 × 107
PBX-2 30 °C/1 MPa 1.176 × 106 1.036 × 105 515.85 3.016 × 104 15.71 5.016 × 108
45 °C/1 MPa 6.690 × 105 2.607 × 104 739.07 1.557 × 104 25.39 3.601 × 108
60 °C/1 MPa 4.376 × 105 1.468 × 104 526.74 6.297 × 103 20.97 2.082 × 108
80 °C/1 MPa 1.300 × 105 9.542 × 103 525.30 6.234 × 103 13.38 1.570 × 108
PBX-3 30 °C/1 MPa 1.859 × 106 8.275 × 105 243.01 5.439 × 104 15.91 1.261 × 109
45 °C/1 MPa 2.468 × 106 6.494 × 104 1401.03 2.271 × 104 25.74 9.222 × 108
60 °C/1 MPa 6.503 × 106 1.921 × 104 682.68 1.751 × 104 32.64 2.604 × 108
80 °C/1 MPa 1.497 × 106 1.278 × 104 517.99 1.206 × 104 38.89 2.565 × 108

3.4.4 Prediction of long-term creep behaviors. For the binary TATB/fluoropolymer systems, the creep strains which were measured at a temperature range of 30–80 °C (Fig. 5) and a stress of 1 MPa are used to construct the three-point bending master curves of creep strain at the reference temperature of 30 °C. Fig. 7 gives the representative double logarithmic plots for TATB-based PBXs at different temperatures under 1 MPa. It can be seen that the shape of double logarithmic plots of the individual creep process are similar. Therefore, long-term predictions are easily obtained based on time-temperature superposition (TTS) concept, as presented in Fig. 8. Since the PBX's mechanical properties are dominated by the binder, the master curves of creep strain for PBXs also depend on the molecular structure of polymer binder. The results reveal that the replacement of F2311 by F2313 and F2314 leads to a creep strain decrease within the time scale. The significantly improved creep resistance is due to the mobility restriction of polymer chains with decreasing VDF/CTFE molar ratio.
image file: c5ra10255c-f7.tif
Fig. 7 Double logarithmic plots of three-point bending creep strain for TATB-based PBXs under 1 MPa: (a) PBX-1; (b) PBX-2; (c) PBX-3.

image file: c5ra10255c-f8.tif
Fig. 8 Three-point bending creep strain master curves of pure TATB and TATB-based PBXs.

4. Conclusions

The present work investigated and compared the creep behaviors of PBXs based on three types of fluoropolymers, i.e. F2311, F2313, and F2314, with different molar ratios of comonomer vinylidene fluoride (VDF) and chlorotrifluoroethylene (CTFE) at various temperatures and stresses. Dynamic mechanical analysis and static mechanical measurement results revealed that the glass transition temperature of fluoropolymer shifted to higher temperatures and the mechanical strength was enhanced with the decrease of VDF/CTFE molar ratio. Consequently, the decrease of VDF/CTFE molar ratio in fluoropolymers remarkably improved the mechanical strength and the creep resistance of TATB-based PBXs. The TATB/F2313 composites showed a significant reduction in the creep deformation and a dramatically increase in the creep failure time, compared to that of the TATB/F2311 composites. The improved creep properties of the composites were likely attributed to the inhibited mobility of F2313 molecular chains. The molar ratio of comonomer VDF and CTFE for polymer binder change from 1[thin space (1/6-em)]:[thin space (1/6-em)]3 (F2313) to 1[thin space (1/6-em)]:[thin space (1/6-em)]4 (F2314) results in a further modification of creep behaviors. Based on the analytical modeling (six-element mechanical model) and experimental results, the influences of molecular structure of polymer binder on the creep performance of TATB-based PBXs were discussed. The long-term creep behavior, which was predicted based on time-temperature superposition (TTS) concept, suggested that the TATB/F2314 composites provided much lower creep response compared to that of the TATB/F2311 and TATB/F2313 composites. The research presented here indicated that changing the molecular structure in polymer binder, such as comonomer molar ratio, is an effective way to tune the creep performance of the PBXs.

References

  1. S. F. Trevino and D. A. Wiegand, J. Energ. Mater., 2008, 26, 79–80 CrossRef CAS PubMed.
  2. A. Wuillaume, A. Beaucamp, F. David-Quillot and C. Eradès, Propellants, Explos., Pyrotech., 2014, 39, 390–396 CrossRef CAS PubMed.
  3. Q. Yan, S. Zeman and A. Elbeih, Thermochim. Acta, 2012, 537, 1–12 CrossRef CAS PubMed.
  4. P. W. Cooper and S. R. Kurowski, Introduction to the Technology of Explosives, Wiley-VCH, New York, pp. 21–23, 1996 Search PubMed.
  5. S. F. Trevino and D. A. Wiegand, J. Energ. Mater., 2008, 26, 79–80 CrossRef CAS PubMed.
  6. C. M. Tarver and J. G. Koerner, J. Energ. Mater., 2008, 26, 1–28 CrossRef CAS PubMed.
  7. D. M. Hoffman, J. Energ. Mater., 2001, 19, 163–193 CrossRef CAS PubMed.
  8. H. F. Rizzo, J. R. Humphrey and J. R. Kolb, Growth of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). II. Control of growth by use of high Tg polymeric bingers, Propellants, Explos., Pyrotech., 1981, 6, 27–36 CrossRef CAS PubMed.
  9. J. Xiao, X. Ma, W. Zhu, Y. Huang, H. Xiao, H. Huang and J. Li, Propellants, Explos., Pyrotech., 2007, 32, 355–359 CrossRef CAS PubMed.
  10. X. Ma, J. Xiao, H. Huang, X. Ju, J. Li and H. Xiao, Chin. J. Chem., 2006, 24, 473–477 CrossRef CAS PubMed.
  11. L. L. Stevens, D. M. Dattelbaum, M. Ahart and R. J. Hemley, J. Appl. Phys., 2012, 112, 023523 CrossRef PubMed.
  12. Q. L. Yan, S. Zeman and A. Elbeih, Thermochim. Acta, 2013, 562, 56–64 CrossRef CAS PubMed.
  13. C. Lin, J. Liu, G. He, L. Chen, Z. Huang, F. Gong, Y. Liu and S. Liu, RSC Adv., 2015, 5, 35811–35820 RSC.
  14. C. Lin, J. Liu, S. Liu, X. Tu, Z. Huang, Y. Li and J. Zhang, Chin. J. Energ. Mater., 2014, 22, 798–803 Search PubMed.
  15. D. M. Hoffman, Polym. Eng. Sci., 2003, 43, 139–156 CAS.
  16. C. Souers, P. Lewis, M. Hoffman and B. Cunningham, Propellants, Explos., Pyrotech., 2011, 36, 335–340 CrossRef PubMed.
  17. R. L. Gustavsen, R. J. Gehr, S. M. Bucholtz, R. R. Alcon and B. D. Bartram, J. Appl. Phys., 2012, 112, 074909 CrossRef PubMed.
  18. W. Small IV, E. A. Glascoe and G. E. Overturf, Thermochim. Acta, 2012, 545, 90–95 CrossRef PubMed.
  19. N. K. Bourne and G. T. Gray III, J. Appl. Phys., 2005, 98, 123503 CrossRef PubMed.
  20. Y. Zhang, G. Ji, F. Zhao, Z. Gong, D. Wei, L. Chen and W. Li, Mol. Simul., 2011, 37, 237–242 CrossRef CAS PubMed.
  21. J. Xiao, W. Zhu, X. Ma, H. Xiao, H. Huang and J. Li, Mol. Simul., 2008, 34, 775–779 CrossRef CAS PubMed.
  22. J. Xiao, X. Ma, W. Zhu, Y. Huang, H. Xiao, H. Huang and J. Li, Propellants, Explos., Pyrotech., 2007, 32, 355–359 CrossRef CAS PubMed.
  23. Y. Ding, Y. Pan, R. Cai, X. Yu and Y. Yang, Chin. J. Energ. Mater., 2000, 8, 87–90 Search PubMed.
  24. C. Lin, S. Liu, X. Tu, Z. Huang, Y. Li, L. Pan and J. Zhang, Propellants, Explos., Pyrotech., 2015, 40, 189–196 Search PubMed.
  25. C. Lin, J. Liu, F. Gong, G. Zeng, Z. Huang, L. Pan, J. Zhang and S. Liu, RSC Adv., 2015, 5, 21376–21383 RSC.
  26. C. Lin, S. Liu, Z. Huang, G. He, F. Gong, Y. Liu and J. Liu, RSC Adv., 2015, 5, 30592–30601 RSC.
  27. X. Wang, L. Gong, L. Tang, K. Peng, Y. Pei, L. Zhao, L.-B. Wu and J. Jiang, Composites, Part A, 2015, 69, 288–298 CrossRef CAS PubMed.
  28. P. Frübing, F. Wang and M. Wegener, Appl. Phys. A: Mater. Sci. Process., 2012, 107, 603–611 CrossRef.
  29. Y. P. Khanna and R. Kumar, Polymer, 1991, 32, 2010–2013 CrossRef CAS.
  30. M. Wen, W. Tang, X. Zhou, H. Pang and F. Zhu, Chinese J. Energ. Mater., 2013, 21, 490–494 CAS.
  31. M. Ganss, B. K. Satapathy, M. Thunga, R. Weidisch, P. Potschke and A. Janke, Macromol. Rapid Commun., 2007, 28, 1624–1633 CrossRef CAS PubMed.
This journal is © The Royal Society of Chemistry 2015
Click here to see how this site uses Cookies. View our privacy policy here.