Carl Scliorlcininer" Leuna-Merseburg, Sektion Physik, DDR-4200 hlerseburg 13C-NMK-Messungen (22,635 MHz) wurden durchgefuhrt, uni die Sequenzmikrostruktur in Vinylacetat/Ethylacrylat/ Acrylslure-Terpol3.mere11 bei variiertem Etliylacrylatanteil und vernachlassigbarem Acrylsaureanteil zu bestimmen. Die Rcsonanzen des Metlii~ikol~lenstoffs wurden auf Triaden, die des Metliylenkolilerlstoffj der Hauptkette auf Diaden von Monomereinheiten zuruckgefuhrt. Aus den Teilstrukturhaufigkeiteii wurden folgeiide Mikrostrukturparameter bestimmt : niittlere Blockliingen, Blockzahl, Blockparameter iind Reaktivitatenprodukt r\'ACrEA und mit den fur statistische Verteilung bcrecli tieten Werten verglichen. l"-II~~P-uccnedoeauus pacripedeJLenus nocnedosarrienb~ocmeu e mepnonu&epux sumnayeritama c a m u a a~p u n a m o~ u atcpunosoli aucaomoli f l n~ onpeReneHm Mmpompymypbi nocneaonaTenmocTeii n Tepnonmepax n~l~a n a y e~a~a c aTmaHpmaToM II aKpanosoti K H C J I O T O~~ npa p a a n u q~b~x coaepmaHaRx aTunaKpsnaTa II n p e~e 6 p e r a e~o i a o n~ aKpmoBoi HHCJIOTM MeTmeHonoro ymepoaa m a m o t qenu RkiaRaMa MoHoMepHbIx ~R H H H~. no qacToTe qacTmHbIx CTPJ-KTY~ onpegeneHM cneaymqae napaMeTpM MHKpocTpyKTypbr: cpeaHm a s m a BJIOKOB, wcno Bno~on, napaMeTpbI B~O K O B H npompacnpeneaeirm.lVr-NMt< irioestigatiori of the sequence distribution in terpolyniers of vinyl acetate, ehyl ucrylate and acrylic acid rWNMH measurements were carried out in order to determine the microstructure of sequences in tcrpolymcrs of vinyl acetate, ethyl acrylate and acrylic acid with varying amounts of ethyl acrylate and negligible a~u o u n t of acrylic acid. The resoiiances of the metliin carbon were assigned t o triads, that of methylene carbon of the main chain to diads of the monomer units. The following microstructure parameters were determined from the particle frequency and compared with data calculated from the statistical distribution: mean block length, arnouut of blocks, block parameter aiid reactivily product r V A C r E A .npone&elrbI 13C-HMP-H3MepeHHR npH 22,635 Mrq. PeBOHaHCbI MeTAHOBOI' O yl'JIepOJ&a 06%ACHRKlTCH TpHanaMH, a BeaeHHe peaKTHBHOCTefi rgAU . r3A. 3 T H napaMeTpb1 CpaBHeHbI C ,L(aHHbIMH, BbI9HCJIeHHblMH RJIX CTaTMCTHSeCKOPO

Mechanical properties of thermoplastic polymers can be improved by incorporation of nanoscaled layered silicates. To achieve a significant improvement, the silicates have to be well exfoliated within the polymer matrix. However, it is not always possible to produce exfoliated nanocompounds with the standard procedure of melt compounding. As an alternative to melt compounding, an in situ process for the production of polyamide 6-nanocompounds is investigated. During the in situ production, the layered silicates are dispersed in the monomer caprolactam prior to the step of polymerization in a twin-screw extruder, leading to an intercalation of the silicate filler. The production of a polyamide compound containing 0, 2, and 4 wt % nanoscaled silicates was successful. Young's modulus was increased by $ 30-60%.

An in situ process for the production of polyamide‐6 nanocompounds is investigated as an alternative to melt compounding. During the in situ production, the layered silicates are dispersed in the monomer caprolactam before the polymerisation in a twin screw extruder, leading to an intercalation of the silicates. The production of a polyamide compound containing 0, 2 and 4 wt.‐% nanoscale silicates was successful. An improvement of the elastic modulus of approximately 30–60% was reached. The figure shows the TEM micrograph of a nanocompound containing 2 wt.‐% nanoclay at a magnification of 30 000×.magnified image

No abstract

Carl Schorlemmer" Leuna-Merseburg, Sektion Physik, DDR -4200 Merseburg Experimentelle Ergebnisse von Ultraschalldampfungsmessungen an Polyvinylacetatdispersioncn werden vorgestellt. Die MeBfrequenz variiert zwischen 150 kHz und 1 GHz. Das Dampfungsverhalten dieser Dispersionen wurde auBerhalb auftretender Relaxationen beobachtet. Die UberschuDdampfung zeigte bei allen Typen Proportionalitat zur Frequenz im Bereich von vier Dekaden. Dieses experimentelle Verhalten wurde rnit theoretischen Vorstellungen verglichen. Es erwies sich, daB die Schalldampfung in Polymerdispersionen in einem sehr groDen Frequenzbereich gut beschreibhar ist mit Modellen, die fur andere heterogene Systeme Anwendung finden. 0 nomoiqenuu ym-mpaaeyica ico~aouano-aucnepcnb,ncu nomuwpnmw cucmmantu nPHBOHRTCR pe3yJIbTaTbI U3MepeHUR IIOrJIO~eHHR yJIbTpa3ByKa AMClIePCHRMH IIOJIHBHHMJIaQeTaTa IIpU YaCTOTaX MempJ 150 HrQ U 1 rrq. CnOC06HOCTb 3TKX HIlCnePCHfi K IlOrJIO~eHUH, yJIbTpa3ByHa ll3yqaJIaCb B OTCyTCTBHe penancaqAoHHbIx npoqeccoB.Bcex o6paaqoa AHcnepcHfi 1436b1Toq~oe nornoqeHne o~a a a n o c b nponopqAoaanb-HMM sawore B gmanaao~e 9eTbIpeX IXOPRAKOB. 3~c n e p~~e~~a n b~o Ha6~110AaeMoe noseAeHtie AHcnepcnB cpamn-BaJIOCb C TeOPeTIlqCKUMEl Ilpe~CTaBJIeHHRMU. BbIJIO yCTaHOBJIeH0, 9TO nOrJIOWeHKe 3 B Y K a llOJIHMepHbIMH .QHClIepCH-RMEl B IlIHPOKOM AHana30He qaCTOT XOpOrUO OIIElCbIBaeTCR MOAeJIRMII, HClIOJIb3YeMbIMIl AJIH ApyrHX reTepOreHHbIX CIICTeM. The ultrasonic attenuation in colloid disperse polymer systemsThe ultrasonic attenuation of PVAC-dispersions outside the relaxation regions has been studied in the frequency range between 150 kHz and 1 GHz. With all studied samples the excess attenuation is proportional to the frequency over a range of four decades. Comparing the experimental results with theoretical model shows that sound attenuation in polymer dispersions can be explained by a model proposed for other heterogeneous systems.