Growth Kinetics of Polyethylene Single Crystals. I. Growth of (110) Faces of Crystals from Dilute Solutions in Xylene

Cooper, Matthew A.; Manley, R. St. John

doi:10.1021/ma60044a024

Cited by 52 publications

(30 citation statements)

References 11 publications

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“…7 the variation of the growth rate with molecular weight is shown at three crystallization temperatures for the concentrations 0.1, 0.01 and 0.001 wt%. The profiles ok these curves are substantially the same as those obtained using xylene as the solvent (1). One difference between the two solvents may be noted towards the low molecular ends ok the curves: the decrease ok the growth rate with decreasing molecular weight is less marked when the solvent is decalin.…”

Section: With Reference To the Solvent P R O Perties And The T W O Nsupporting

confidence: 56%

“…T h e trends in the g r o w t h rate of polyethylene single crystals as g r o w n f r o m the t w o solvents, decalin and octane, will be c o mpared with the results presented earlier for xylene (1) (2, 3). Unfortunately since the variation of the equilibrium dissolution temperature ( T O ) with molecular w e i g h t is not k n o w n for decalin or octane, it is n o t possible to generate theoretical curves for the t w o nucleating mechanisms for these solvent systems ( T ° being required to define the undercooling).…”

Section: Growth Ratesmentioning

confidence: 73%

“…The polyethylene fractions were the same as those used in the previous work (1). The molecular weights and polydispersities are shown in tab.…”

Section: Methodsmentioning

confidence: 99%

“…1. Growth rates were measured at various temperatures and concentrations using experimental techniques identical to those described earlier (1). As before, the selfseeding method (7,8) was used to initiate crystal growth at the desired temperature and concentration.…”

Section: Methodsmentioning

confidence: 99%

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Growth kinetics of polyethylene single crystals: (II) Growth of {110} faces of crystals from dilute solutions in decalin and in octane

Cooper

Manley

1976

Colloid Polymer Sci

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Section: With Reference To the Solvent P R O Perties And The T W O Nsupporting

confidence: 56%

Section: Growth Ratesmentioning

confidence: 73%

“…The polyethylene fractions were the same as those used in the previous work (1). The molecular weights and polydispersities are shown in tab.…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Growth kinetics of polyethylene single crystals: (II) Growth of {110} faces of crystals from dilute solutions in decalin and in octane

Cooper

Manley

1976

Colloid Polymer Sci

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“…It is of special interest to note that Cooper and Manley [46] have found some evidence for the exist· ence of a regime I ~ regime II transition in polyethyl· ene fractions crystallized from dilute solution. We observe that the transition, though not as well·defined in the ailute solution case as in the case of crystalliza· tion from the melt, appears to occur at approximately the same undercooling in both cases.…”

Section: Regime I and Regime Ii In Other Polymersmentioning

confidence: 99%

On the growth rate of spherulites and axialites from the melt in polyethylene fractions: Regime I and regime II crystallization

Hoffman

Frolen

Ross

et al. 1975

J. RES. NATL. BUR. STAN. SECT. A.

483

262

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Th e growth rate C of th e cr ys tallin e bodi es a pp ea rin g in eac h of a se t of 35 c haracte rize d po ly. e th ylen e fracti ons ra ngin g from 3600 to 807 ,000 in molec ular we ight ha s been meas ured as a fun ction of th e unde rcoolin g tJ.T. In isoth e rmal c rys tallization, only ax ial ites we re found from M",= 3600 to 18 ,000.(For th ese run s, tJ.T < 17.5 °C.) From M".= 18 ,000 to M". "" 115,000 coa rse·grain ed non ·band e d s phe ru · lit es we re fo und for tJ.T > 17. 5 °C , and axialites for tJ.T < 17.5 °C : a rathe r s ha rp brea k occ urre d in th e log .o C ve r sus T data at tJ.T "" 17.5 0c. Th e morphologi ca l changes we re more gradual. Above Mil' "" 115,-000, only nea rly s tru ctureless " irregular" s ph erulit es we re found a t all und e rcoolin gs corres pondin g to isothermal growth. Typica l rin ged sphe rulites were o btain ed only on quenching. Wid e·a ng le x·ray data s howed that th e usu al orthorhombi c subce ll predominat ed in all th e morph ologies e ncount e re d. Lo w· angle x·ray data showed tha t th e s pec ime ns ex hibit e d lam e llar crystallization irres pectiv e of th e particular gross morphology involv ed. Th e growth rat e data on eac h fra c tion we re analyzed us in g /T (tJ.T )/]where / "" I to obtain va lu es of K" a nd Co. Th e va lue of Y in K,,= Ybuue/ (tJ.hj )k was obta ined fo r eac h morphology by a ppl ying th e "Z" test of La uritze n. Y = 4 for regim e I cr ys talli zation (s in gle s urface nucl eus leads to co mpl etio n of s ubs trat e) and Y =2 for regim e II cr ys talli za tio n (num e rous s urface nu c lei involve d in s ubstra te co mp letion). It wa s found that the axia lites obeyed regim e I kin e tics (Y=4), th e coarse·grain e d s phe rulit es regime II kin etics (Y = 2), and th e irregular s ph e r ulit es " mix e d " kineti cs (Y -3). Th e ass umpti on that th e sub strat e le ngth L in Laurit ze n's regim e theory was -5 I'-m led to the prediction of a rath e r s harp regim e 1 ..... regime II tran sition (corresponding to a break in the 10glO C versus T dat a) a t tJ.T "" 17 .5 °C, in accord with ex pe riment. Th e UUe value ca lc ulat ed fro m K" and Y for M". ;;. 20 ,000 was ap proxim ate ly co nst a nt with molec ular we ight and indep end e nt of morphology; th e limiting value of uU e from kineti c meas ure me nt s was about 1285 e rg'/c m 4 • corre· s ponding to Ue(x)=90.5 erg/e m ' and u= 14.2 erg/c m ' . (This valu e of Ut'{x) co mpare s favorably with u dcQ)= 93 ± 8 e rg/ cm ' from me ltin g point expe riment s.) T he in c rease of uUe and U e that too k place at low mol ec ul ar we ight s on up to -20 ,000 was treat e d usin g an expression given by Hoffman , viz , Ue=Udx) [(,.,+/3;) / (,.,+1)] where v=number of fo ld s per molecule, /3; = U"c;lIum)/Ud x) , I ntermittent hi gh and low values of U e were found ex p erim entally in thi s regio n , s howin g that j3 ; varied with in creas· in g mol ec ular we ight between 0.15 and -0.7. Theore tic al estimates of these upper and lowe r bound s for /3; are give n . Th e ...

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Crystallization Kinetics

Hobbs¹

2004

Encyclopedia of Polymer Science and Technology

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Crystallization kinetics is the area of polymer science that deals with the rate at which randomly ordered chains transform into highly ordered crystals, and includes every aspect of the resultant structure that is dependent on the route that was taken between those different states. It is a broad and mature area of scientific research, given and uncommon diversity when compared to the crystallization of small molecules because of the wide range of different chemistries and chain topologies that are available to macromolecules. These add layers of comlexity that can make it difficult to find generalizing principles. The article concentrates on principles and observations that have the widest applicability. Crystallizable polymers form semicrystalline materials containing chains or fractions of chains that are trapped in nonequilibrium, amorphous states. Because of this semicrystalline nature, the crystal morphology, rather than the underlying crystal structure, often controls the final properties of a polymer article. Because polymers crystallize so far from equilibrium conditions, a simple examination of the phase diagram gives us little insight into the crystal morphology that is formed or the route that is taken to its formation. To understand, and ultimately control, such behavior, it is necessary to gain an understanding of the kinetics of crystallization, as it is the kinetics of the process that define the structure and properties of the material.

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Growth Kinetics of Polyethylene Single Crystals. I. Growth of (110) Faces of Crystals from Dilute Solutions in Xylene

Cited by 52 publications

References 11 publications

Growth kinetics of polyethylene single crystals: (II) Growth of {110} faces of crystals from dilute solutions in decalin and in octane

Growth kinetics of polyethylene single crystals: (II) Growth of {110} faces of crystals from dilute solutions in decalin and in octane

On the growth rate of spherulites and axialites from the melt in polyethylene fractions: Regime I and regime II crystallization

Crystallization Kinetics

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