The temperature-induced crystallisation (TIC) and strain-induced crystallisation (SIC) of natural rubber (NR)/isoprene rubber (IR) blends varying in blend ratio were mainly studied by dilatometers and wide-angle X-ray diffraction measurements (WAXD). The dilatometers results showed that the real half-life of crystallisation (t1/2) values of unvulcanised NR/IR blends were 50% less than the theoretical half-life of crystallisation values. From WAXD measurements, the degree of crystallisation of vulcanised NR/IR with IR content samples 30, 50 and 70% at strain 500% were larger than theoretical crystallinity values by 17.17, 19.99 and 29.69%. NR can significantly improve the property of crystallinity of IR during TIC and SIC processes. The results can be ascribed to the end-linked networks existing in NR which can simultaneously induce amorphous NR and IR chains into crystalline order in NR/IR blends and increase the crystallinity and crystallisation rate during TIC and SIC process.
AllenPW, JonesKP. In: RobertsAD, editor. Chapter 1: Foreword. Preface. A historical perspective of the rubber industry. Natural rubber science and technology. Oxford, UK: Oxford University Press; 1988. p. 1–34.
2.
LiangY, GuoY, WangE, Details of molecular organization during strain-induced crystallization in natural rubber/clay systems as revealed by real-time mechano-optical behavior. Macromolecules. 2015;48(7):2299–2304. doi: 10.1021/acs.macromol.5b00231
3.
CandauN, ChazeauL, ChenalJM, Strain induced crystallization and melting of natural rubber during dynamic cycles. Phys Chem Chem Phys. 2015;17(23):15331–15338. doi: 10.1039/C5CP00384A
4.
ChenL, ZhouW, SuF, Filler-induced heterogeneous distribution of stretch-induced crystallization in natural rubber: An in-situ synchrotron-radiation micro-focused scanning X-ray diffraction study. Polymer. 2017;115:217–223. doi: 10.1016/j.polymer.2017.03.043
5.
KangMK, JeonHJ, SongHH, Strain-induced crystallization of blends of natural rubber and ultra high cis-polybutadiene as studied by synchrotron X-ray diffraction. Macromol Res. 2016;24(1):31–36. doi: 10.1007/s13233-016-4014-8
6.
CheJ, BurgerC, TokiS, Crystal and crystallites structure of natural rubber and synthetic cis-1,4-polyisoprene by a new two dimensional wide angle X-ray diffraction simulation method. I. Strain-induced crystallization. Macromolecules. 2013;46(11):4520–4528. doi: 10.1021/ma400420k
7.
ClamrothR, KempermannT.Comparison of methods for the determination of tear strength. Polym Test. 1986;6(1):3–35. doi: 10.1016/0142-9418(86)90031-0
8.
GentAN, KawaharaS, ZhaoJ.Crystallization and strength of natural rubber and synthetic cis-1, 4-polyisoprene. Rubber Chem Technol. 1998;71(4):668–678. doi: 10.5254/1.3538496
9.
JosephR, GeorgeKE, FrancisDJ.Studies on the cure characteristics and vulcanizate properties of 50/50 NR/SBR blend. J Appl Polym Sci. 1988;35(4):1003–1017. doi: 10.1002/app.1988.070350415
10.
RamesanMT, AlexR, KhanhNV.Studies on the cure and mechanical properties of blends of natural rubber with dichlorocarbene modified styrene-butadiene rubber and chloroprene rubber. React Funct Polym. 2005;62(1):41–50. doi: 10.1016/j.reactfunctpolym.2004.08.002
11.
CookS.Blends of natural rubber. 1st ed.London: Chapman and Hall; 1998.
12.
Sae-OuiP, SirisinhaC, ThepsuwanU, Influence of accelerator type on properties of NR/EPDM blends. Polym Test. 2007;26(8):1062–1067. doi: 10.1016/j.polymertesting.2007.07.004
13.
BoochathumP, ChiewnawinS.Vulcanization of cis- and trans-polyisoprene and their blends: Crystallization characteristics and properties. Eur Polym J. 2001;37(3):429–434. doi: 10.1016/S0014-3057(00)00138-5
14.
JiangH, YueH, ZhaoJY, Molecular dynamics simulation of the mechanical properties of NR/TPI. Adv Mater Res. 2012;560–561:1114–1118. doi: 10.4028/www.scientific.net/AMR.560-561.1114
15.
QuL, HuangG, NieY, Strain-induced crystallization behavior of natural rubber and trans-1,4-polyisoprene crosslinked blends. J Appl Polym Sci. 2010;120(3):1346–1354. doi: 10.1002/app.33243
16.
BekkedahlN.Forms of rubber as indicated by temperature-volume relationship. Rubber Chem Technol. 1935;8(1):5–22. doi: 10.5254/1.3548287
17.
GentAN.Crystallization and the relaxation of stress in stretched natural-rubber vulcanizates. Trans Faraday Soc. 1954;50(1):521–533. doi: 10.1039/tf9545000521
18.
TrabelsiS, AlbouyP-A, RaultJ.Crystallization and melting processes in vulcanized stretched natural rubber. Macromolecules. 2003;36(20):7624–7639. doi: 10.1021/ma030224c
19.
TokiS, SicsI, RanS, New insights into structural development in natural rubber during uniaxial deformation by in situ synchrotron X-ray diffraction. Macromolecules. 2002;35(17):6578–6584. doi: 10.1021/ma0205921
20.
MitchellGR.A wide-angle X-ray study of the development of molecular orientation in crosslinked natural rubber. Polymer. 1984;25(11):1562–1572. doi: 10.1016/0032-3861(84)90148-4
21.
TosakaM, MurakamiS, PoompradubS, Orientation and crystallization of natural rubber network as revealed by WAXD using synchrotron radiation. Macromolecules. 2004;37(9):3299–3309. doi: 10.1021/ma0355608
22.
TosakaM, SenooK, SatoK, Detection of fast and slow crystallization processes in instantaneously-strained samples of cis-1,4-polyisoprene. Polymer. 2012;53(3):864–872. doi: 10.1016/j.polymer.2011.12.035
23.
ZhaoF, ZhaoS, WeinaB, Characterization of elastomer networks by NMR parameters part I. KGK Rubberpoint. 2007;60(10):554–558.
24.
De CandiaF, RomanoG.Melting behavior of cis-polybutadiene crystallized under stress. J Appl Polym Sci. 1989;38(2):249–256. doi: 10.1002/app.1989.070380205
25.
GentAN, ZhangLQ.Strain-induced crystallization and strength of elastomers. I. cis-1,4-polybutadiene. J Polym Sci Polym Phys. 2001;39(7):811–817. doi: 10.1002/1099-0488(20010401)39:7<811::AID-POLB1055>3.0.CO;2-C
26.
BekkedahlN.Crystallization of natural rubber. Rubber Chem Technol. 1967;40(3):25–47. doi: 10.5254/1.3539082
27.
HuneauB.Strain-induced crystallization of natural rubber: a review of X-ray diffraction investigations. Rubber Chem Technol. 2011;84(3):425–452. doi: 10.5254/1.3601131
28.
KnillCJ, KennedyJF. In: BrandrupJ, ImmergutEH, GrulkeEA, editors. VI. Solid state properties: crystallographic data and melting points for various polymers. Polymer handbook 4th ed. New York: Wiley; 1999. xiii+2288 p., ISBN 0-471-16628-6 (£226-00). Carbohydrate Polymers, 2001, 46:295. p. VI 1-192.
29.
TokiS, CheJ, RongL, Entanglements and networks to strain-induced crystallization and stress–strain relations in natural rubber and synthetic polyisoprene at various temperatures. Macromolecules. 2013;46(13):5238–5248. doi: 10.1021/ma400504k
30.
GentAN.Crystallization in natural rubber. IV. Temperature dependence. J Polym Sci. 1955;18(89):321–334. doi: 10.1002/pol.1955.120188901
31.
GentAN, ZhangLQ.Strain-induced crystallization and strength of rubber. Rubber Chem Technol. 2002;75(5):923–934. doi: 10.5254/1.3547692
32.
FraserRDB, MacraeTP, MillerA, Digital processing of fibre diffraction patterns. J Appl Crystallogr. 1976;9(2):81–94. doi: 10.1107/S0021889876010674
33.
CheJ, BurgerC, TokiS, Crystal and crystallites structure of natural rubber and peroxide-vulcanized natural rubber by a two-dimensional wide-angle X-ray diffraction simulation method. II. Strain-induced crystallization versus temperature-induced crystallization. Macromolecules. 2013;46(46):9712–9721. doi: 10.1021/ma401812s
34.
ImmirziA, TedescoC, MonacoG, Crystal structure and melting entropy of natural rubber. Macromolecules. 2005;38:1223–1231. doi: 10.1021/ma047935a
35.
TokiS, FujimakiT, OkuyamaM.Strain-induced crystallization of natural rubber as detected real-time by wide-angle X-ray diffraction technique. Polymer. 2000;41(14):5423–5429. doi: 10.1016/S0032-3861(99)00724-7
36.
TokiS, SicsI, RanS, Molecular orientation and structural development in vulcanized polyisoprene rubbers during uniaxial deformation by in situ synchrotron X-ray diffraction. Polymer. 2003;44(19):6003–6011. doi: 10.1016/S0032-3861(03)00548-2
37.
TokiS, SicsI, HsiaoBS, Structural developments in synthetic rubbers during uniaxial deformation by in situ synchrotron X-ray diffraction. J Polym Sci, Polym Phys. 2004;42(6):956–964. doi: 10.1002/polb.10679
38.
NieY, GuZ, WeiY, Feature of strain-induced crystallization of natural rubber revealed by experiments and simulations. Polym J. 2017;49(3):309–317. doi: 10.1038/pj.2016.114
39.
EdwardsSF, VilgisTA.The effect of entanglements in rubber elasticity. Polymer. 1986;27:483–492. doi: 10.1016/0032-3861(86)90231-4
40.
RajkumarG, SquireJM, ArnottS.A new structure for crystalline natural rubber. Macromolecules. 2006;39(20):7004–7014. doi: 10.1021/ma0600310
